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Reducing Carbon Dioxide Emissions: Using the Mole Concept.
ERIC Educational Resources Information Center
Provides an application of quantitative chemistry concepts in the context of motor vehicle emissions. Shows how carbon dioxide emissions from cars may be reduced by up to 25% by reducing motorway speeds from 70-75 mph to 60 mph. (Author/MM)
Myers, Alan
Can reducing black carbon emissions counteract global warming?
Field measurements and model results have recently shown that aerosols may have important climatic impacts. One line of inquiry has investigated whether reducing climate-warming soot or black carbon aerosol emissions can form a viable component of mitigating global warming. Black carbon is produced by poor combustion, from our example hard coal cooking fires for and industrial pulverized coal boilers. The authors review and acknowledge scientific arguments against considering aerosols and greenhouse gases in a common framework, including the differences in the physical mechanisms of climate change and relevant time scales. It is argued that such a joint consideration is consistent with the language of the United Nations Framework Convention on Climate Change. Results from published climate-modeling studies are synthesized to obtain a global warming potential for black carbon relative to that of CO{sub 2} (680 on a 100 year basis). This calculation enables a discussion of cost-effectiveness for mitigating the largest sources of black carbon. It is found that many emission reductions are either expensive or difficult to enact when compared with greenhouse gases, particularly in Annex I countries. Finally, a role for black carbon in climate mitigation strategies is proposed that is consistent with the apparently conflicting arguments raised during the discussion. Addressing these emissions is a promising way to reduce climatic interference primarily for nations that have not yet agreed to address greenhouse gas emissions and provides the potential for a parallel climate agreement. 31 refs., 3 figs., 1 tab.
Tami C. Bond; Haolin Sun [University of Illinois at Urbana-Champaign, Urbana, IL (US)
Institute a modest carbon tax to reduce carbon emissions, finance clean energy technology development, cut taxes, and reduce the deficit
The nation should institute a modest carbon tax in order to help clean up the economy and stabilize the nationĺs finances. Specifically, Congress and the president should implement a $20 per ton, steadily increasing carbon excise fee that would discourage carbon dioxide emissions while shifting taxation onto pollution, financing energy efficiency (EE) and clean technology development, and providing opportunities to cut taxes or reduce the deficit. The net effect of these policies would be to curb harmful carbon emissions, improve the nationĺs balance sheet, and stimulate job-creation and economic renewal.
Muro, Mark; Rothwell, Jonathan
Challenges for Reducing Emissions of Black Carbon from the Transport Sector in Urban Areas
NASA Astrophysics Data System (ADS)
The transport sector is a large contributor of harmful gaseous and particulate emissions in many urban areas. Black carbon is a component of short-lived particulate matter emitted predominantly by freight, public transport, and heavy- duty trucks. Controlling the emissions of black carbon from the transport sector is important for mitigating its impacts on climate, ecosystems, and human health. However, reducing the emissions of black carbon from mobile sources may be a challenging task in many developing urban areas due to economic, social, and technical constrains. Several emissions control technologies offer a proven approach for reducing emissions of black carbon from diesel-powered mobile sources, but the accurate quantification of associated emissions benefits in developing urban areas is not well documented. We describe recent advances for the estimation of black carbon emissions from the transport sector in real world driving conditions and present examples of the potential benefits of implementing various emission control technologies in Mexico. The results can help in the identification of key factors that hinder the implementation of control emissions for reducing emissions of black carbon elsewhere.
Zavala, M. A.; Molina, L. T.
Economic Effects of Using Carbon Taxes to Reduce Carbon Dioxide Emissions in Major OECD Countries.
National Technical Information Service (NTIS)
A tax on fossil fuels designed to obtain a 20 percent reduction in emissions of carbon dioxide by the year 2020 would lower output among major OECD nations by 1 to 3 1/2 percent. The tax required to achieve a 20% reduction in emissions of carbon dioxide b...
Arctic Black Carbon Initiative: Reducing Emissions of Black Carbon from Power & Industry in Russia
NASA Astrophysics Data System (ADS)
Deposition of black carbon (BC) on snow and ice is widely considered to have a climate warming effect by reducing the surface albedo and promoting snowmelt. Such positive climate feedbacks in the Arctic are especially problematic because rising surface temperatures may trigger the release of large Arctic stores of terrestrial carbon, further amplifying current warming trends. Recognizing the Arctic as a vulnerable region, the U.S. government committed funds in Copenhagen in 2009 for international cooperation targeting Arctic BC emissions reductions. As a result, the U.S. Department of State has funded three research and demonstration projects with the goal to better understand and mitigate BC deposition in the Russian Arctic from a range of sources. The U.S. Department of Energy's (DOE) Arctic BC initiative presented here is focused on mitigating BC emissions resulting from heat and power generation as well as industrial applications. A detailed understanding of BC sources and its transport and fate is required to prioritize efforts to reduce BC emissions from sources that deposit in the Russian Arctic. Sources of BC include the combustion of fossil fuels (e.g. coal, fuel oil, diesel) and the combustion of biomass (e.g. wildfires, agricultural burning, residential heating and cooking). Information on fuel use and associated emissions from the industrial and heat & power sectors in Russia is scarce and difficult to obtain from the open literature. Hence, our project includes a research component designed to locate Arctic BC emissions sources in Russia and determine associated BC transport patterns. We use results from the research phase to inform a subsequent assessment/demonstration phase. We use a back-trajectory modeling method (potential source contribution function - PSCF), which combines multi-year, high-frequency measurements with knowledge about atmospheric transport patterns. The PSCF modeling allows us to map the probability (by season and year) at course resolution (2.5░ x 2.5░ spatial resolution) that a particular region emits BC which deposits in the Russian Arctic. We utilize data from three Arctic measurement stations during the most recent decade: Alert, Northwest Territories, Canada; Barrow, Alaska; and Tiksi Bay, Russia. To understand more about individual Arctic BC sources, we conduct further research to improve inventory estimates of Russian industrial and energy sector BC emissions. By comparing inventory data on power plant locations and emissions from two publically-available databases (EDGAR-HTAP and CARMA databases) to each other and to additional observations from satellites and the AERONET observation network in Russia, we assess the accuracy of the Russian BC emission inventory in EDGAR-HTAP, a commonly used database for atmospheric transport modeling. We then use a global (GEOS-CHEM) atmospheric transport model to quantify the finer spatial distribution of BC within the Arctic. Lastly, we use data on Russian fuel use combined with published emissions factors to build a national-scale model of energy use and associated emissions from critical industrial and heat & power sources of BC. We use this model to estimate the technical potential of reducing BC emissions through proven mitigation efforts such as improvements in energy efficiency and in emission control technologies.
Cresko, J.; Hodson, E. L.; Cheng, M.; Fu, J. S.; Huang, K.; Storey, J.
Abstract This paper uses a numerical general equilibrium model to compare the costs of alternative policies for reducing carbon emissions in a second-best setting with a distortionary tax on labor. We examine a carbon tax, two energy taxes, and both narrow-based and br...
Flexible field emission of nitrogen-doped carbon nanotubes/reduced graphene hybrid films.
The outstanding flexible field emission properties of carbon hybrid films made of vertically aligned N-doped carbon nanotubes grown on mechanically compliant reduced graphene films are demonstrated. The bottom-reduced graphene film substrate enables the conformal coating of the hybrid film on flexible device geometry and ensures robust mechanical and electrical contact even in a highly deformed state. The field emission properties are precisely examined in terms of the control of the bending radius, the N-doping level, and the length or wall-number of the carbon nanotubes and analyzed with electric field simulations. This high-performance flexible carbon field emitter is potentially useful for diverse, flexible field emission devices. PMID:21104826
Lee, Duck Hyun; Lee, Jin Ah; Lee, Won Jong; Kim, Sang Ouk
Incorporation of catalytic dehydrogenation into fischer-tropsch synthesis to significantly reduce carbon dioxide emissions
A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO.sub.2 emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H.sub.2 level of coal-derived syngas for FTS. Additionally, the FTS-CDH process saves large amounts of water used by the WGS reaction and produces a valuable by-product, MWCNT.
Huffman, Gerald P.
New Hampshire Carbon Challenge: Reducing Residential Energy Use and Greenhouse Gas Emissions
NASA Astrophysics Data System (ADS)
The New Hampshire Carbon Challenge is an initiative of the Institute for the Study of Earth, Oceans and Space at the University of New Hampshire. Our goal is to educate New Hampshire residents about climate change and also encourage them to reduce their household greenhouse gas emissions by 10,000 pounds. The Northeast region is undergoing climate changes consistent with those expected due to increasing levels of CO2 in the atmosphere, while also contributing to climate change as the world's seventh largest source of CO2 emissions. In the USA, approximately 40 percent of CO2 emissions from fossil fuel combustion come from residential energy consumption for space heating, electricity usage, and transportation. Homeowners typically are not aware that modest energy reductions can result in significant carbon savings. Most campaigns that raise awareness of climate change and residential energy usage disseminate information to consumers through newspaper articles, brochures, websites, or other traditional means of communication. These information-only campaigns have not been very effective in changing residential energy consumption. Bombarded with information in their daily lives, the public has become quite adept at tuning most of it out. When much of the information they receive about climate change is confusing and contradictory, residents have even less incentive to change their behavior. The Challenge is unique in that it couples accurate information about climate change with concrete actions homeowners can take to reduce their carbon emissions. Our strategy is to utilize the tools of Community Based Social Marketing, which has been shown to be effective in changing behavior, and also to leverage existing networks including the NH Department of Environmental Services, UNH Cooperative Extension, faith-based communities, municipal energy committees and Climate Project volunteers, to effectively reach residents throughout the state. The response to our program has been very positive. We gave 74 presentations to 4000 NH residents since the program was launched in October 2006. We are currently developing web-based tools tailored to New Hampshire residents that will enable them to track reductions in their energy usage and connect those reductions to reduced emissions, and will provide us feedback as to which actions households are willing to take. This type of information exchange is essential in creating and sustaining an effective and scientifically accurate public outreach campaign.
Schloss, A. L.; Bartlett, D.; Blaha, D.; Skoglund, C.; Dundorf, J.; Froburg, E.; Pasinella, B.
Guidance for Determining Best Available Control Technology for Reducing Carbon Dioxide Emissions from Bioenergy Production.
National Technical Information Service (NTIS)
This guidance provides an illustration of reasoning that a Prevention of Significant Deterioration (PSD) permitting authority may use to support the conclusion that the best available control technology (BACT) for carbon dioxide (CO2) emissions at a bioen...
Carbonation of alkaline paper mill waste to reduce CO 2 greenhouse gas emissions into the atmosphere
The global warming of Earthĺs near-surface, air and oceans in recent decades is a direct consequence of anthropogenic emission of greenhouse gases into the atmosphere such as CO2, CH4, N2O and CFCs. The CO2 emissions contribute approximately 60% to this climate change. This study investigates experimentally the aqueous carbonation mechanisms of an alkaline paper mill waste containing about 55wt% portlandite
R. PÚrez-Lˇpez; G. Montes-Hernandez; J. M. Nieto; F. Renard; L. Charlet
The paper gives results of tests (to aid in developing emission rules) in July and August 1991 on a 360-tonne/day mass burn municipal waste combustor (MWC) at the Ogden Martin Systems of Stanislaus, Inc. facility near Crows Landing, CA. est results indicated that carbon (C) addit...
Economic effects of using carbon taxes to reduce carbon dioxide emissions in major OECD countries. Final report
A tax on fossil fuels designed to obtain a 20 percent reduction in emissions of carbon dioxide by the year 2020 would lower output among major OECD nations by 1 to 3 1/2 percent. The tax required to achieve a 20% reduction in emissions of carbon dioxide by 2020 ranged from $489.4 (Sweden) per metric ton of carbon to $2,427.9 (Japan) per ton of carbon. The tax required for the U.S. was $720.6 per ton. In the U.S., a tax per $100 per ton of carbon would equate to a tax of $70.68 per short ton of coal, $11.42 per barrel of oil, $1.66 per MCF of natural gas and 0.27 per gallon of gasoline. The study is part of a multi-phase effort to gauge the economic consequences of various measures being discussed by the international community to mitigate the possibility of global climate change by limiting emissions of carbon dioxide from fossil fuel use. The study assumed that the carbon tax program would be revenue neutral in that increased revenues from the carbon tax would be offset by reductions in personal income taxes.
Not Available
Biofuels from crop residue can reduce soil carbon and increase CO2 emissions
NASA Astrophysics Data System (ADS)
Removal of corn residue for biofuels can decrease soil organic carbon (SOC; refs , ) and increase CO2 emissions because residue C in biofuels is oxidized to CO2 at a faster rate than when added to soil. Net CO2 emissions from residue removal are not adequately characterized in biofuel life cycle assessment (LCA; refs , , ). Here we used a model to estimate CO2 emissions from corn residue removal across the US Corn Belt at 580 million geospatial cells. To test the SOC model, we compared estimated daily CO2 emissions from corn residue and soil with CO2 emissions measured using eddy covariance, with 12% average error over nine years. The model estimated residue removal of 6 Mg per ha-1 yr-1 over five to ten years could decrease regional net SOC by an average of 0.47-0.66 Mg C ha-1 yr-1. These emissions add an average of 50-70 g CO2 per megajoule of biofuel (range 30-90) and are insensitive to the fraction of residue removed. Unless lost C is replaced, life cycle emissions will probably exceed the US legislative mandate of 60% reduction in greenhouse gas (GHG) emissions compared with gasoline.
Liska, Adam J.; Yang, Haishun; Milner, Maribeth; Goddard, Steve; Blanco-Canqui, Humberto; Pelton, Matthew P.; Fang, Xiao X.; Zhu, Haitao; Suyker, Andrew E.
Use of videoconferencing in Wales to reduce carbon dioxide emissions, travel costs and time.
In September 2005 a telemedicine service was started to assist multidisciplinary teams in Wales to improve cancer services. In October 2006 and October 2007 users of videoconferencing equipment at one site completed questionnaires. During October 2006 a total of 18,000 km of car travel were avoided, equivalent to 1696 kg of CO(2) emission. During October 2007 a total of 20,800 km of car travel were avoided, equivalent to 2590 kg of CO(2) emission. We estimate that 48 trees would take a year to absorb that quantity of CO(2). The results of the surveys show that exploiting telemedicine makes better use of staff time, reduces the time spent travelling and assists in reducing climate change by limiting the emissions of CO(2). PMID:19364897
Lewis, Delyth; Tranter, Glynis; Axford, Alan T
Household actions can provide a behavioral wedge to rapidly reduce US carbon emissions
Most climate change policy attention has been addressed to long-term options, such as inducing new, low-carbon energy technologies and creating cap-and-trade regimes for emissions. We use a behavioral approach to examine the reasonably achievable potential for near-term reductions by altered adoption and use of available technologies in US homes and nonbusiness travel. We estimate the plasticity of 17 household action types in 5 behaviorally distinct categories by use of data on the most effective documented interventions that do not involve new regulatory measures. These interventions vary by type of action and typically combine several policy tools and strong social marketing. National implementation could save an estimated 123 million metric tons of carbon per year in year 10, which is 20% of household direct emissions or 7.4% of US national emissions, with little or no reduction in household well-being. The potential of household action deserves increased policy attention. Future analyses of this potential should incorporate behavioral as well as economic and engineering elements.
Dietz, Thomas; Gardner, Gerald T.; Gilligan, Jonathan; Stern, Paul C.; Vandenbergh, Michael P.
To reduce its carbon emissions, a Vermont college draws on the power of cows
NSDL National Science Digital Library
Green Mountain Becomes First Campus Powered by Vermont Dairy Cowshttp://www.greenmtn.edu/gmcjournal/pop_102306_cow_power.aspLocal farm leading way for green powerhttp://www.addisonindependent.com/?q=node/295CVPS Cow Power [Macromedia Flash Player]http://www.cvps.com/cowpower/Cow%20Power%20home.htmlThe Ashden Awards for Sustainable Energyhttp://www.ashdenawards.org/Vermont is a state that is known for its passion in developing alternative farming methods and independence in its political thought. Now it can lay claim to another important recent development in its long history. As of this week, Green Mountain College in the town of Poultney is believed to be the first college in the United States that will be powered by cows. To be accurate, however, it should be noted that the energy that will be shipped to Green Mountain via the Central Vermont Public Service├ó┬┬s ├ó┬┬Cow Power├ó┬┬ program. Power will be created from burning biogas created from cow manure. Initially, the college will derive approximately fifty percent of its energy needs for the main campus from this new energy source. It is estimated that this will allow the college to reduce its carbon emissions by approximately 3500 metric tons per year. There├ó┬┬s a great deal of interest in this program, and the school├ó┬┬s provost, Bill Throop recently commented that ├ó┬┬We want our students learning how to support sustainable communities right here in Vermont and this helps us lead by example.├ó┬┬ The first link will take visitors to a CNN news article on this recent development in creating a sustainable energy source on the campus of Green Mountain College. Moving along, the second link leads to a press release from the Green Mountain College Journal which provides some nice details on this new initiative. The third link leads to an article from this Monday├ó┬┬s Addison Independent, which reports on the efforts of the Foster Brothers Farm in Middlebury, Vermont to create a new company that will allow them to sell electricity produced, on farms across the United States. The fourth link will take users to a very fun and informative site provided by the Central Vermont Public Service which explains the niceties of their ├ó┬┬Cow Power├ó┬┬ program, and also includes a great segment on ├ó┬┬How Energy Happens├ó┬┬. The last and final link leads to the homepage of The Ashden Awards for Sustainable Energy. Here, visitors can learn about these rather interesting awards, which honor organizations that have made commitments to developing practical sustainable energy technologies.
Grinnell, Max
The sum of the parts: can we really reduce carbon emissions through individual behaviour change?
Individuals are increasingly being urged to 'do their bit' in the fight against climate change, with governments and pro-environmentalists insisting that the collective impact of small behaviour changes will result in a meaningful reduction in global carbon emissions. The following paper considers this debate, as well as offering personal contributions from two leading environmentalists: Dr Doug McKenzie-Mohr, environmental psychologist and author of Fostering Sustainable Behavior: Community-Based Social Marketing; and Dr Tom Crompton, change strategist for WWF and co-author of Meeting Environmental Challenges: The Role of Human Identity, who argues for the role of intrinsic value systems in achieving sustainable behaviour change. As well as considering the responsibility of the individual in mitigating climate change, the paper introduces the discipline of social marketing as an effective tool for facilitating individual behaviour change, drawing on evidence from the field to recommend the key characteristics of effective behaviour change programmes. PMID:20333949
Reynolds, Lucy
The Potential for Energy-Efficient Technologies to Reduce Carbon Emissions in the United States: Transport Sector
The world is searching for a meaningful answer to the likelihood that the continued build-up of greenhouse gases in the atmosphere will cause significant changes in the earth`s climate. If there is to be a solution, technology must play a central role. This paper presents the results of an assessment of the potential for cost-effective technological changes to reduce greenhouse gas emissions from the U.S. transportation sector by the year 2010. Other papers in this session address the same topic for buildings and industry. U.S.transportation energy use stood at 24.4 quadrillion Btu (Quads) in 1996, up 2 percent over 1995 (U.S. DOE/EIA, 1997, table 2.5). Transportation sector carbon dioxide emissions amounted to 457.2 million metric tons of carbon (MmtC) in 1995, almost one third of total U.S. greenhouse gas emissions (U.S. DOE/EIA,1996a, p. 12). Transport`s energy use and CO{sub 2} emissions are growing, apparently at accelerating rates as energy efficiency improvements appear to be slowing to a halt. Cost-effective and nearly cost-effective technologies have enormous potential to slow and even reverse the growth of transport`s CO{sub 2} emissions, but technological changes will take time and are not likely to occur without significant, new public policy initiatives. Absent new initiatives, we project that CO{sub 2} emissions from transport are likely to grow to 616 MmtC by 2010, and 646 MmtC by 2015. An aggressive effort to develop and implement cost-effective technologies that are more efficient and fuels that are lower in carbon could reduce emissions by about 12% in 2010 and 18% in 2015, versus the business-as- usual projection. With substantial luck, leading to breakthroughs in key areas, reductions over the BAU case of 17% in 2010 and 25% in 2015,might be possible. In none of these case are CO{sub 2} emissions reduced to 1990 levels by 2015.
Greene, D.L.
Potential for reduced methane and carbon dioxide emissions from livestock and pasture management in the tropics
We estimate the potential reductions in methane and carbon dioxide emissions from several livestock and pasture management options in the mixed and rangeland-based production systems in the tropics. The impacts of adoption of improved pastures, intensifying ruminant diets, changes in land-use practices, and changing breeds of large ruminants on the production of methane and carbon dioxide are calculated for two levels of adoption: complete adoption, to estimate the upper limit to reductions in these greenhouse gases (GHGs), and optimistic but plausible adoption rates taken from the literature, where these exist. Results are expressed both in GHG per ton of livestock product and in Gt CO2-eq. We estimate that the maximum mitigation potential of these options in the land-based livestock systems in the tropics amounts to approximately 7% of the global agricultural mitigation potential to 2030. Using historical adoption rates from the literature, the plausible mitigation potential of these options could contribute approximately 4% of global agricultural GHG mitigation. This could be worth on the order of $1.3 billion per year at a price of $20 per t CO2-eq. The household-level and sociocultural impacts of some of these options warrant further study, however, because livestock have multiple roles in tropical systems that often go far beyond their productive utility.
Thornton, Philip K.; Herrero, Mario
Black Carbon in the Arctic: Assessment of and efforts to reduce black carbon emissions from wildfires and agricultural burning in Russia
NASA Astrophysics Data System (ADS)
Black carbon and other short-lived climate forcers exert a warming effect on the climate but remain in the atmosphere for short time periods when compared to carbon dioxide. Black carbon is a significant contributor to increasing temperatures in the Arctic region, which has warmed at twice the global rate over the past 100 years. Black carbon warms the Arctic by absorbing incoming solar radiation while in the atmosphere and, when deposited onto Arctic ice, leading to increased atmospheric temperatures and snow and ice melt. Black carbon remains in the atmosphere for a short time period ranging from days to weeks; therefore, local atmospheric conditions at the time of burning determine the amount of black carbon transport to the Arctic. Most black carbon transport and deposition in the Arctic results from the occurrence of wildfires, prescribed forest fires, and agricultural burning at latitudes greater than 40 degrees north latitude. Wildfire affects some 10-15 million hectares of forest, forest steppe, and grasslands in Russia each year. In addition to wildfire, there is widespread cropland burning in Russia occurring in the fall following harvest and in the spring prior to tilling. Agricultural burning is common practice for crop residue removal as well as suppression of weeds, insects and residue-borne diseases. The goal of the United States Department of Agriculture (USDA) Black Carbon Initiative is to assess black carbon emissions from agricultural burning and wildfires in Russia and explore practical options and opportunities for reducing emissions from these two sources. The emissions assessment combines satellite-derived burned area measurements of forest and agricultural fires, burn severity information, ancillary geospatial data, vegetation and land cover maps, fuels data, fire emissions data, fire/weather relationship information, and smoke transport models to estimate black carbon transport and deposition in the Arctic. The assessment addresses necessary improvements to fire and burned area detection algorithms to improve agricultural burned area mapping accuracy. Efforts to explore practical options for reducing black carbon emissions from wildfires and agricultural burning in Russia have been focused on designing community-based fire prevention and education programs in Siberia and the Russia Far East, two regions prone to frequent human-caused fires. The initiative also seeks to identify practical alternatives to reduce black carbon emissions from agricultural burning and to help promote these alternatives through outreach to farmers and other agricultural organizations. This submission will explore the initial findings and results of the emissions assessment and discuss the progress and challenges associated with implementation of local-level fire prevention and mitigation efforts in Russia. The results of this initiative will help inform future policy and management tools to address black carbon emissions from wildfires and agricultural burning in Russia and perhaps additional interested countries.
Kinder, B.; Hao, W. M.; Larkin, N. K.; McCarty, G.; O'neal, K. J.; Gonzalez, O.; Luxenberg, J.; Rosenblum, M.; Petkov, A.
Strategies for Carbon Sequestration and Reducing Greenhouse Gas Emissions from Nursery Production Systems.
National Technical Information Service (NTIS)
Over the past three decades, climate change and its potential impacts on the global environment have received significant attention from the scientific community. Increased atmospheric carbon dioxide (CO2) concentration, along with other trace gases (i e....
C. H. Gilliam G. B. Runion H. A. Torbert S. A. Prior S. C. Marble
Societal Consequences of Carbon Dioxide Emissions: Impacts to Well Being of Reduced Fossil Fuel Dependence.
NASA Astrophysics Data System (ADS)
The threat of global warming raises important questions about ways human activities are altering the biophysical environment. The burning of fossil fuels by modern societies is a principal contributor to greenhouse gases implicated in climate change. Furthermore, there is growing concern about how global environmental changes anticipated due to global warming may impact the long-term sustainability of all societies. The threat of global warming challenges scientists and policy makers to further our understanding of relationships among fossil fuel consumption and CO_2, emissions on the one hand, and economic and social well-being on the other. This challenge is especially germane to the industrialized countries, for they are the largest consumers of fossil fuels. This study comprises a multiwave panel design focused on the period 1950-1985 for twenty-three highly industrialized nations. A trend analysis showed that CO _2 emissions diverged along three separate patterns after 1970, grouping countries into one of the three patterns, while measures of societal well -being continued on their historical trajectories. Numerous comparisons made via a path analysis showed that the amount of fossil fuel consumed had a continued positive impact on economic well-being. At the same time overall fossil fuel consumption had a declining and sometimes negligible direct effect on various dimensions of social well-being over the time period. On the general welfare and modern life-style dimensions, the positive impact of economic well-being overshadowed the impact of fossil fuel consumption. Both fossil fuel consumption and economic well-being had a declining negative influence on health and safety and an insignificant effect on life stress. The structure of energy use, reflected in gross land mass, appeared to have an important influence on fossil fuel consumption, with greater geographical dispersion leading to greater fossil fuel consumption. However while the structure of energy use appeared to have an important impact on economic well-being and modern life-style, it had a negligible impact on general welfare, health and safety and life stress.
Krebill-Prather, Rose Louise
The U.S. Federal Government's Efforts to Estimate an Economic Value for Reduced Carbon Emissions (Invited)
NASA Astrophysics Data System (ADS)
This presentation will summarize the technical process and results from recent U.S. Federal government efforts to estimate the ôsocial cost of carbonö (SCC); the monetized damages associated with an incremental increase in carbon dioxide emissions in a given year. The purpose of the SCC estimates is to make it possible for Federal agencies to incorporate the social benefits from reducing CO2 emissions into cost-benefit analyses of regulatory actions that have relatively small impacts on cumulative global emissions. An interagency working group initiated a comprehensive analysis using three integrated assessment models. The interagency group chose to rely on three of the most widely recognized peer-reviewed models to fairly represent differences in the way in which economic impacts from climate change are modeled (DICE, PAGE, and FUND). The main objective of this process was to develop a range of SCC values using a defensible set of input assumptions grounded in the existing scientific and economic literatures. In this way, key uncertainties and model differences transparently and consistently inform the range of SCC estimates used in the rulemaking process. This proved challenging since the literature did not always agree on the best path forward. In some cases the group agreed to a range of assumptions to allow for uncertainty analysis (e.g., they include 5 different socioeconomic scenarios in the Monte Carlo analysis to reflect uncertainty about how future economic and population growth and energy systems will develop over the next 100 years). The four values selected for regulatory analysis included three estimates based on the average SCC from three integrated assessment models over a range of discount rates, since there is wide disagreement on which to apply in an inter-generational context. The fourth value represents the 95th percentile SCC estimate across all three models at a 3 percent discount rate and is included to represent higher-than-expected impacts from temperature change further out in the tails of the SCC distribution. The interagency working group recognized that there are a number of serious challenges in attempting to assess the incremental economic impacts of CO2 emissions. A recent report from the National Academies of Science (NRC 2009) points out that any assessment will suffer from uncertainty, speculation, and lack of information about future emissions of greenhouse gases, the effects of emissions on the climate system, the impact of changes in climate on the physical and biological environment, and the translation of these environmental impacts into economic damages. In addition to highlighting key areas in need of future research in the interagency technical document, the Department of Energy and the Environmental Protection Agency are planning two workshops that will bring the very best climate modelers from the scientific and economic community together to discuss key gaps in the literature and how to improve current modeling capabilities. I will briefly summarize the main outcomes from the first of two workshops, scheduled to occur in November 2010.
Wolverton, A.
Potential for Woody Bioenergy Crops Grown on Marginal Lands in the US Midwest to Reduce Carbon Emissions
NASA Astrophysics Data System (ADS)
While cellulosic biofuels are widely considered to be a low carbon energy source for the future, a comprehensive assessment of the environmental sustainability of existing and future biofuel systems is needed to assess their utility in meeting US energy and food needs without exacerbating environmental harm. To assess the carbon emission reduction potential of cellulosic biofuels, we need to identify lands that are initially not storing large quantities of carbon in soil and vegetation but are capable of producing abundant biomass with limited management inputs, and accurately model forest production rates and associated input requirements. Here we present modeled results for carbon emission reduction potential and cellulosic ethanol production of woody bioenergy crops replacing existing native prairie vegetation grown on marginal lands in the US Midwest. Marginal lands are selected based on soil properties describing use limitation, and are extracted from the SSURGO (Soil Survey Geographic) database. Yield estimates for existing native prairie vegetation on marginal lands modeled using the process-based field-scale model EPIC (Environmental Policy Integrated Climate) amount to ~ 6.7▒2.0 Mg ha-1. To model woody bioenergy crops, the individual-based terrestrial ecosystem model ED (Ecosystem Demography) is initialized with the soil organic carbon stocks estimated at the end of the EPIC simulation. Four woody bioenergy crops: willow, southern pine, eucalyptus and poplar are parameterized in ED. Sensitivity analysis of model parameters and drivers is conducted to explore the range of carbon emission reduction possible with variation in woody bioenergy crop types, spatial and temporal resolution. We hypothesize that growing cellulosic crops on these marginal lands can provide significant water quality, biodiversity and GHG emissions mitigation benefits, without accruing additional carbon costs from the displacement of food and feed production.
Sahajpal, R.; Hurtt, G. C.; Fisk, J. P.; Izaurralde, R. C.; Zhang, X.
Carbon Dioxide Emission Estimates
NSDL National Science Digital Library
The Carbon Dioxide Information Analysis Center of the Oak Ridge National Laboratory provides this new data on carbon dioxide emissions from fossil fuel burning, hydraulic cement production, and gas flaring in 1995. Data for one degree grid cells can be downloaded from the site in addition to code for analysis of the data.
The role of market and technical downsizing in reducing carbon emissions from the Swedish new car fleet
Doubts have been raised on whether the car industry will manage to reach the goal set by the Voluntary Agreement with the\\u000a European Commission, unless tougher measures are taken to reduce CO2 emissions. Taking a stance from the concept of downsizing, we study the historical development of two strategies: first,\\u000a shifting the market toward smaller cars, market downsizing; second, a
Frances Sprei; Sten Karlsson
Forest carbon response to management scenarios intended to mitigate GHG emissions and reduce fire impacts in the US West Coast region
NASA Astrophysics Data System (ADS)
US West coast forests are among the most carbon dense biomes in the world and the potential for biomass accumulation in mesic coastal forests is the highest recorded (Waring and Franklin 1979, Hudiburg et al. 2009). Greenhouse gas (GHG) mitigation strategies have recently expanded to include forest woody biomass as bioenergy, with the expectation that this will also reduce forest mortality. We examined forest carbon response and life cycle assessment (LCA) of net carbon emissions following varying combinations of bioenergy management scenarios in Pacific Northwest forests for the period from 2010-2100. We use the NCAR CLM4 model combined with a regional atmospheric forcing dataset and account for future environmental change using the IPCC RCP4.5 and RCP 8.5 scenarios. Bioenergy management strategies include a repeated thinning harvest, a repeated clearcut harvest, and a single salvage harvest in areas with projected insect-related mortality. None of the bioenergy management scenarios reduce net emissions to the atmosphere compared to continued business-as-usual harvest (BAU) by the end of the 21st century. Forest regrowth and reduced fire emissions are not large enough to balance the wood removals from harvest. Moreover, the substitution of wood for fossil fuel energy and products is not large enough to offset the wood losses through decomposition and combustion. However, in some ecoregions (Blue Mountains and East Cascades), emissions from the thinning harvests begin to improve over BAU at the end of the century and could lead to net reductions in those ecoregions over a longer time period (> 100 years). For salvage logging, there is no change compared to BAU emissions by the end of the 21st century because the treatment area is minimal compared to the other treatments and only performed once. These results suggest that managing forests for carbon sequestration will need to include a variety of approaches accounting for forest baseline conditions and in some ecoregions, harvest reductions below current levels will sequester more carbon than additional harvest removals for bioenergy. References: Hudiburg, T., B. E. Law, D. P. Turner, J. Campbell, D. Donato, and M. Duane. 2009. Carbon dynamics of Oregon and Northern California forests and potential land-based carbon storage. Ecological Applications 19:163-180. Waring, R. H., and J. F. Franklin. 1979. Evergreen Coniferous Forests of the Pacific Northwest. Science 204:1380-1386.
Hudiburg, T. W.; Law, B. E.; Thornton, P. E.; Luyssaert, S.
Summary of the presentations at the international workshop on reducing carbon dioxide emissions from the developing world: Assessment of benefits, costs and barriers
The International Workshop on Reducing Carbon Dioxide Emissions from the Developing World: Assessment of Benefits, Costs and Barriers'' was the second workshop held as part of a project being conducted by the International Energy Studies Group of Lawrence Berkeley Laboratory, in collaboration with experts from leading institutions across the developing world. The goal of the project is to analyze long-range energy consumption in developing countries and its potential contribution to global climate change. The US Environmental Protection Agency (EPA) is supporting this work, the results of which already have made a key contribution to the technical analysis being used as the basis for discussion by the Energy and Industry Sub-group of the Intergovernmental Panel on Climate Change (IPCC). The main purpose of this workshop was two-fold: (1) to discuss the feasibility of implementing the efficiency improvements and fuel switching measures incorporated into the long-term energy scenarios created for 17 developing countries and (2) to examine the costs and benefits of reducing energy-related carbon dioxide emissions generated by developing countries.
Sathaye, J.; Goldman, N. (eds.)
Summary of the presentations at the international workshop on reducing carbon dioxide emissions from the developing world: Assessment of benefits, costs and barriers
The ``International Workshop on Reducing Carbon Dioxide Emissions from the Developing World: Assessment of Benefits, Costs and Barriers`` was the second workshop held as part of a project being conducted by the International Energy Studies Group of Lawrence Berkeley Laboratory, in collaboration with experts from leading institutions across the developing world. The goal of the project is to analyze long-range energy consumption in developing countries and its potential contribution to global climate change. The US Environmental Protection Agency (EPA) is supporting this work, the results of which already have made a key contribution to the technical analysis being used as the basis for discussion by the Energy and Industry Sub-group of the Intergovernmental Panel on Climate Change (IPCC). The main purpose of this workshop was two-fold: (1) to discuss the feasibility of implementing the efficiency improvements and fuel switching measures incorporated into the long-term energy scenarios created for 17 developing countries and (2) to examine the costs and benefits of reducing energy-related carbon dioxide emissions generated by developing countries.
Sathaye, J.; Goldman, N. [eds.
Electron Field Emission from Nanostructured Carbon Materials
Fabricating small structures has almost become fashionable and the rationale is that reducing one or more dimensions below some critical length changes the systems' physical properties drastically, where nanocrystalline diamond (n-D) and carbon nanotubes (CNTs) in the class of advanced carbon materials serve model examples. Emission of electrons at room temperature - cold electron emitters - are of vital importance
Sanju Gupta
Burner retrofits reduce brewery emissions
In 1988, the South Coast Air Quality Management District in California (SCAQMD) tightened its grip on industrial emissions of nitrogen oxides (NOx). The new statute, Rule 1146, mandates a 75% reduction in NOx emissions over a five-year period ending this July. Anheuser-Busch Inc.'s second-largest brewery in Van Nuys fell under the new law's jurisdiction. Under the new law, the maximum allowable NOx emission must be reduced from 120 to 30 ppm for the two largest boilers. There were two alternatives: either prevent its formation inside the boiler, or remove it from the off-gases via selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR). Prevention was chosen, because the NOx-removal technologies are unproven in the US on natural-gas-fired boilers. In addition, it was not known whether SCR or SNCR could respond to the wide swings in boiler demand. At any given time, loads between 30 and 100% of capacity would be required from the boilers. The brewery retrofitted the 125,000-lb/h boilers with Variflame burners, based upon an earlier retrofit at Anheuser-Busch's Merrimack, N.H., brewery. The paper describes this burner and its performance.
Not Available
Determination of elemental carbon emission.
The studies on elemental carbon content in the atmospheric air, performed at the air monitoring station in Katowice (Poland), have revealed violations of allowable maximum average annual and diurnal concentrations. Elemental carbon is introduced into the atmosphere mainly as soot generated from combustion processes. This work presents the determination of elemental carbon in emission generated from coal combustion processes. PMID:24221230
Mniszek, W; Wypych, J; Zielonka, U
An Evaluation of CO2 Emission Reduction through Carbonation Technology
Researchers around the world are studying on different carbon capture and storage (CCS) options to reduce global warming by reducing CO2 emission from various sources. Among all these options carbonation technology has some promising benefits over other technologies such as exothermic heat, availability of feed stocks, safe carbonated product and value added product and by-product, etc. In carbonation technology CO2
S. Moazzem; M. G. Rasul; M. M. K. Khan
Large Scale U.S. Unconventional Fuels Production and the Role of Carbon Dioxide Capture and Storage Technologies in Reducing Their Greenhouse Gas Emissions
This paper examines the role that carbon dioxide capture and storage technologies could play in reducing greenhouse gas emissions if a significant unconventional fuels industry were to develop within the United States. Specifically, the paper examines the potential emergence of a large scale domestic unconventional fuels industry based on oil shale and coal-to-liquids (CTL) technologies. For both of these domestic heavy hydrocarbon resources, this paper models the growth of domestic production to a capacity of 3 MMB/d by 2050. For the oil shale production case, we model large scale deployment of an in-situ retorting process applied to the Eocene Green River formation of Colorado, Utah, and Wyoming where approximately 75% of the high grade oil shale resources within the United States lies. For the CTL case, we examine a more geographically dispersed coal-based unconventional fuel industry. This paper examines the performance of these industries under two hypothetical climate policies and concludes that even with the wide scale availability of cost effective carbon dioxide capture and storage technologies, these unconventional fuels production industries would be responsible for significant increases in CO2 emissions to the atmosphere. The oil shale production facilities required to produce 3MMB/d would result in net emissions to the atmosphere of between 3000-7000 MtCO2 in addition to storing potentially 1000 to 5000 MtCO2 in regional deep geologic formations in the period up to 2050. A similarly sized domestic CTL industry could result in 4000 to 5000 MtCO2 emitted to the atmosphere in addition to potentially 21,000 to 22,000 MtCO2 stored in regional deep geologic formations over the same period up to 2050. Preliminary analysis of regional CO2 storage capacity in locations where such facilities might be sited indicates that there appears to be sufficient storage capacity, primarily in deep saline formations, to accommodate the CO2 from these industries. However, additional analyses plus detailed regional and site characterization is needed, along with a closer examination of competing storage demands.
Dooley, James J.; Dahowski, Robert T.
Cermet Filters To Reduce Diesel Engine Emissions
Pollution from diesel engines is a significant part of our nation's air-quality problem. Even under the more stringent standards for heavy-duty engines set to take effect in 2004, these engines will continue to emit large amounts of nitrogen oxides and particulate matter, both of which affect public health. To address this problem, the Idaho National Engineering and Environmental Laboratory (INEEL) invented a self-cleaning, high temperature, cermet filter that reduces heavy-duty diesel engine emissions. The main advantage of the INEEL cermet filter, compared to current technology, is its ability to destroy carbon particles and NOx in diesel engine exhaust. As a result, this technology is expected to improve our nation's environmental quality by meeting the need for heavy-duty diesel engine emissions control. This paper describes the cermet filter technology and the initial research and development effort.Diesel engines currently emit soot and NOx that pollute our air. It is expected that the U.S. Environmental Protection Agency (EPA) will begin tightening the regulatory requirements to control these emissions. The INEEL's self-cleaning, high temperature cermet filter provides a technology to clean heavy-duty diesel engine emissions. Under high engine exhaust temperatures, the cermet filter simultaneously removes carbon particles and NOx from the exhaust gas. The cermet filter is made from inexpensive starting materials, via net shape bulk forming and a single-step combustion synthesis process, and can be brazed to existing structures. It is self-cleaning, lightweight, mechanically strong, thermal shock resistant, and has a high melting temperature, high heat capacity, and controllable thermal expansion coefficient. The filter's porosity is controlled to provide high removal efficiency for carbon particulate. It can be made catalytic to oxidize CO, H2, and hydrocarbons, and reduce NOx. When activated by engine exhaust, the filter produces NH3 and light hydrocarbon gases that can effectively destroy the NOx in the exhaust. The following sections describe cermet filter technology and properties of the INEEL filter.
Kong, Peter
Motor vehicle emissions under reduced ambient temperature idle operating conditions
NASA Astrophysics Data System (ADS)
During winter months, motor vehicles are typically operated with extended preliminary idle periods. Total hydrocarbon, carbon monoxide, nitrogen oxides and formaldehyde emissions are examined under idle operation at 20,40 and 68░F with six gasoline fueled vehicles (including non-catalyst, early catalyst and late model catalyst) and a methanol-fueled prototype vehicle. The emissions were substantially reduced by the late model catalyst control technologies at all temperatures examined. Formaldehyde emissions were elevated with methanol fuel.
Baugh, James; Ray, William; Black, Frank; Snow, Richard
Tanning, in particular chrome leather production, is still characterised by an inefficient use of raw material and the production of highly polluted wastewater and solid wastes. A part of the emissions can be prevented by introducing clean tanning technologies, the remaining emissions can be treated. Clean production technologies and waste (water) treatment technologies should have a designed complimentarity. Anaerobic wastewater
J. W. van Groenestijn; J. S. A. Langerwerf; M. Lucas
Improving material management to reduce greenhouse gas emissions
Climate change due to greenhouse gas emissions caused by human actions is probably one of the major global environmental problems that we face today.\\u000aIn order to reduce the risk of climate change and the potential effects thereof,\\u000athe emission of greenhouse gases like carbon dioxide (CO2) and methane\\u000a(CH4 ) should be reduced.\\u000aMuch greenhouse gases are emitted due
Marko Peter Hekkert
Technology Opportunities to Reduce U.S. Greenhouse Gas Emissions
The rise in greenhouse gas emissions from fossil fuel combustion and industrial and agricultural activities has aroused international concern about the possible impacts of these emissions on climate. Greenhouse gases--mostly carbon dioxide, some methane, nitrous oxide and other trace gases--are emitted to the atmosphere, enhancing an effect in which heat reflected from the earth's surface is kept from escaping into space, as in a greenhouse. Thus, there is concern that the earth's surface temperature may rise enough to cause global climate change. Approximately 90% of U.S. greenhouse gas emissions from anthropogenic sources come from energy production and use, most of which are a byproduct of the combustion of fossil fuels. On a per capita basis, the United States is one of the world's largest sources of greenhouse gas emissions, comprising 4% of the world's population, yet emitting 23% of the world's greenhouse gases. Emissions in the United States are increasing at around 1.2% annually, and the Energy Information Administration forecasts that emissions levels will continue to increase at this rate in the years ahead if we proceed down the business-as-usual path. President Clinton has presented a two-part challenge for the United States: reduce greenhouse gas emissions and grow the economy. Meeting the challenge will mean that in doing tomorrow's work, we must use energy more efficiently and emit less carbon for the energy expended than we do today. To accomplish these goals, President Clinton proposed on June 26, 1997, that the United States ''invest more in the technologies of the future''. In this report to Secretary of Energy Pena, 47 technology pathways are described that have significant potential to reduce carbon dioxide emissions. The present study was completed before the December 1997 United Nations Framework Convention on Climate Change and is intended to provide a basis to evaluate technology feasibility and options to reduce greenhouse gas emissions. These technology pathways (which are described in greater detail in Appendix B, Technology Pathways) address three areas: energy efficiency, clean energy, and carbon sequestration (removing carbon from emissions and enhancing carbon storage). Based on an assessment of each of these technology pathways over a 30-year planning horizon, the directors of the Department of Energy's (DOE's) national laboratories conclude that success will require pursuit of multiple technology pathways to provide choices and flexibility for reducing greenhouse gas emissions. Advances in science and technology are necessary to reduce greenhouse gas emissions from the United States while sustaining economic growth and providing collateral benefits to the nation.
National Lab Directors, . .
Baseline map of carbon emissions from deforestation in tropical regions.
Policies to reduce emissions from deforestation would benefit from clearly derived, spatially explicit, statistically bounded estimates of carbon emissions. Existing efforts derive carbon impacts of land-use change using broad assumptions, unreliable data, or both. We improve on this approach using satellite observations of gross forest cover loss and a map of forest carbon stocks to estimate gross carbon emissions across tropical regions between 2000 and 2005 as 0.81 petagram of carbon per year, with a 90% prediction interval of 0.57 to 1.22 petagrams of carbon per year. This estimate is 25 to 50% of recently published estimates. By systematically matching areas of forest loss with their carbon stocks before clearing, these results serve as a more accurate benchmark for monitoring global progress on reducing emissions from deforestation. PMID:22723420
Harris, Nancy L; Brown, Sandra; Hagen, Stephen C; Saatchi, Sassan S; Petrova, Silvia; Salas, William; Hansen, Matthew C; Potapov, Peter V; Lotsch, Alexander
Baseline Map of Carbon Emissions from Deforestation in Tropical Regions
NASA Astrophysics Data System (ADS)
Policies to reduce emissions from deforestation would benefit from clearly derived, spatially explicit, statistically bounded estimates of carbon emissions. Existing efforts derive carbon impacts of land-use change using broad assumptions, unreliable data, or both. We improve on this approach using satellite observations of gross forest cover loss and a map of forest carbon stocks to estimate gross carbon emissions across tropical regions between 2000 and 2005 as 0.81 petagram of carbon per year, with a 90% prediction interval of 0.57 to 1.22 petagrams of carbon per year. This estimate is 25 to 50% of recently published estimates. By systematically matching areas of forest loss with their carbon stocks before clearing, these results serve as a more accurate benchmark for monitoring global progress on reducing emissions from deforestation.
Harris, Nancy L.; Brown, Sandra; Hagen, Stephen C.; Saatchi, Sassan S.; Petrova, Silvia; Salas, William; Hansen, Matthew C.; Potapov, Peter V.; Lotsch, Alexander
Electron Field Emission from Nanostructured Carbon Materials
NASA Astrophysics Data System (ADS)
Fabricating small structures has almost become fashionable and the rationale is that reducing one or more dimensions below some critical length changes the systems' physical properties drastically, where nanocrystalline diamond (n-D) and carbon nanotubes (CNTs) in the class of advanced carbon materials serve model examples. Emission of electrons at room temperature - cold electron emitters - are of vital importance for a variety of vacuum microelectronic devices - electron microscopes, photo multipliers, X-ray generators, lamps, and flat panel displays and microwave cathodes. Electron emitters may lead to otherwise difficult to obtain advantages in performance and/or design. This is the driving force to investigate the carbon-related materials as cold cathodes. In this talk, the performance of various forms of carbon in thin film form including diamond, n-D, and vertically aligned CNTs as cold cathodes for their potential use in field emission displays (FEDs) in terms of I-V characteristics and corresponding spatial imaging will be presented. Physics based models such as, NEA, surface modification, geometric enhancement, and microstructure alteration due to particle bombardment, and doping, will be described to support the experimental observations of electron field enhancement (low turn-on voltage, high current and emission site density) and its reliability from the abovementioned carbon-related materials. Other vacuum device applications such as thermionic power generators will be mentioned briefly.
Gupta, Sanju
Electricity Load and Carbon Dioxide Emissions: Effects of a Carbon Price in the Short Term
Stabilizing atmospheric carbon dioxide levels at acceptable levels will require a dramatic de-carbonization of the electric generation sector in the U.S. One increasingly discussed way to meet this policy goal is to put an explicit price on carbon emissions, either through a tax or a trading scheme. Increasing demand response has also been discussed as a way to reduce carbon
Adam Newcomer; Seth Blumsack; Jay Apt; Lester B. Lave; M. Granger Morgan
Method of reducing NOx emissions in gasoline vehicles
An unleaded fuel composition is described comprising a major amount of a hydrocarbon base fuel of the gasoline boiling range containing an amount effective to reduce NO[sub x] emissions from electronic port fuel injected engines of an ammonium compound selected from the group consisting of ammonium formate, ammonium propionate, ammonium dicitrate, ammonium carbamate, ammonium carbonate, ammonium acetate, and admixtures thereof.
Gwyn, J.E.
Reduced-carbon footprint concrete compositions
US Patent & Trademark Office Database
Reduced-carbon footprint concrete compositions, and methods for making and using the same, are provided. Aspects of the reduced-carbon footprint concrete compositions include CO.sub.2-sequestering carbonate compounds, which may be present in the hydraulic cement and/or aggregate components of the concrete. The reduced-carbon footprint concrete compositions find use in a variety of applications, including use in a variety of building materials and building applications.
Anthropogenic emissions of carbon monoxide.
Carbon monoxide (CO) is a colorless, nonirritating, odorless and tasteless gas. Carbon monoxide combines with hemoglobin far more readily than does oxygen, leading to tissue hypoxia. Thousands of people die annually from CO poisoning, and those recovering from acute exposure commonly suffer brain damage. Chronic poisoning is of particular concern to sufferers of coronary heart disease, pregnant women, and people with certain hematological disorders. Indoor emission sources, notably fuel-burning heating appliances, cause most unintentional deaths and cases of illness and should be the main focus of concern. Motor vehicle emissions pose a chronic health risk for occupationally exposed groups. Smoking is a major source of personal exposure. Recent exposure to CO is commonly evaluated by measuring blood carboxyhemoglobin levels, which are related to the concentration of atmospheric CO. Monitoring methods are reviewed here, and monitoring is considered in relation to air quality standards and guidelines. Finally, control measures for motor vehicles and indoor heating appliances are suggested. PMID:11048332
Horner, J M
Reducing the carbon footprint of Canadian peat extraction and restoration.
The Canadian horticultural peat industry generates carbon emissions through various methods of peat extraction, processing, and land-use changes. This study provides a carbon emissions analysis comparing the traditional vacuum harvest (VH) and block-cut (BC) extraction techniques to a new acrotelm transplant (AT) method that restores natural peatland function by preserving and replacing the surface layer vegetation as part of the extraction process. The relative global warming potential for each extraction method was determined by estimating carbon dioxide (CO2) and methane exchange for each phase of peat extraction, including emissions from land-use change and machinery fuel consumption. Preliminary findings, based on 1 y of measurements, indicate that the AT technique has the lowest annual carbon emissions compared to the VH and BC methods. Projected total carbon emissions from a 75-ha peatland after 50 y of extraction using the AT technique produced a sink of approximately 3300 t CO2 equivalents (CO2-e). This represents a marked reduction in total carbon emissions estimated for the VH (19 000 t CO2-e) and BC (29 000 t CO2-e) extraction techniques. This analysis suggests that the AT method reestablishes peat accumulation and peatland carbon storage function more effectively than the VH and BC methods, which are associated with delayed restoration efforts. Consequently, the AT technique has the potential to greatly reduce the carbon footprint of the Canadian horticultural peat industry. PMID:19739553
Waddington, James M; Plach, Janina; Cagampan, Jason P; Lucchese, Maria; Strack, Maria
Heat Pipes to Reduce Engine Exhaust Emissions.
National Technical Information Service (NTIS)
A fuel combustor employing heat transfer devices for improving combustion efficiency and reducing engine exhaust emissions is described. The fuel combustor consists of an elongated casing with an air inlet conduit portion at one end. An elongated heat pip...
D. F. Schultz
The Role of Carbon Capture, Sequestration and Emissions Trading in Achieving Short-Term Carbon Emissions Reductions
The near- to mid-term deployment of carbon capture and sequestration technologies can accelerate the process of significantly reducing emissions of carbon dioxide under a wide range of policy scenarios and reduce significantly the costs of complying with a climate change mitigation protocol -- by as much as$1 trillion over the period 2005-2050. These carbon capture and sequestration technologies also allow the continued use of fossil fuels, while reducing their carbon emissions and keeping the cost of electricity generated from fossil fuels competitive with other generation technologies.
Dooley, James J. (BATTELLE (PACIFIC NW LAB)); Kim, Son H. (BATTELLE (PACIFIC NW LAB)); Runci, Paul J. (BATTELLE (PACIFIC NW LAB)); D. Williams
Reducing pollutant emissions by fines removal
A method and apparatus for reducing pollutant emissions, and in particular, for reducing NO \\/SUB x\\/ and particulate emissions, from a spreader-stoker-fired furnace and from a fluidized bed combustor. A combustible material of various sized particles is obtained and those smaller particles which would normally combust during the suspension phase of the spreader-stoker-fired furnace or fluidized bed combustor are separated
D. W. Pershing; G. B. Martin; J. M. Munro
Carbon emission from farm operations.
This manuscript is a synthesis of the available information on energy use in farm operations, and its conversion into carbon equivalent (CE). A principal advantage of expressing energy use in terms of carbon (C) emission as kg CE lies in its direct relation to the rate of enrichment of atmospheric concentration of CO2. Synthesis of the data shows that estimates of emissions in kg CE/ha are 2-20 for different tillage operations, 1-1.4 for spraying chemicals, 2-4 for drilling or seeding and 6-12 for combine harvesting. Similarly, estimates of C emissions in kg CE/kg for different fertilizer nutrients are 0.9-1.8 for N, 0.1-0.3 for P2O5, 0.1-0.2 for K20 and 0.03-0.23 for lime. Estimates of C emission in kg CE/kg of active ingredient (a.i.) of different pesticides are 6.3 for herbicides, 5.1 for insecticides and 3.9 for fungicides. Irrigation, lifting water from deep wells and using sprinkling systems, emits 129+/-98 kg CE for applying 25 cm of water and 258+/-195 for 50 cm of water. Emission for different tillage methods are 35.3 kg CE/ha for conventional till, 7.9 kg CE/ha for chisel till or minimum till, and 5.8 kg CE/ha for no-till method of seedbed preparation. In view of the high C costs of major inputs, sustainable management of agricultural ecosystems implies that an output/input ratio, expressed either as gross or net output of C, must be >1 and has an increasing trend over time. PMID:15196846
Lal, R
A Simple Evaluation Method for Annual CO2 Emissions Reduced by Distribution Loss Minimization
Global warming caused by carbon dioxide (CO2) and other greenhouse gases is one of the serious environmental issues. Carbon dioxide is the biggest contributor to global warming. Many efforts to reduce emissions of CO2 are carrying out in various fields. In electrical power system field, various approaches to reduce CO2 emissions have been performed such as loss reduction, utilization of
Yasuhiro Hayashi; Hirotaka Takano; Junya Matsuki; Masao Yokoyama
Field emission study of carbon nanostructures
NASA Astrophysics Data System (ADS)
Recently, carbon nanosheets (CNS), a novel nanostructure, were developed in our laboratory as a field emission source for high emission current. To characterize, understand and improve the field emission properties of CNS, a ultra-high vacuum surface analysis system was customized to conduct relevant experimental research in four distinct areas. The system includes Auger electron spectroscopy (AES), field emission energy spectroscopy (FEES), field emission I-V testing, and thermal desorption spectroscopy (TDS). Firstly, commercial Mo single tips were studied to calibrate the customized system. AES and FEES experiments indicate that a pyramidal nanotip of Ca and O elements formed on the Mo tip surface by field induced surface diffusion. Secondly, field emission I-V testing on CNS indicates that the field emission properties of pristine nanosheets are impacted by adsorbates. For instance, in pristine samples, field emission sources can be built up instantaneously and be characterized by prominent noise levels and significant current variations. However, when CNS are processed via conditioning (run at high current), their emission properties are greatly improved and stabilized. Furthermore, only H2 desorbed from the conditioned CNS, which indicates that only H adsorbates affect emission. Thirdly, the TDS study on nanosheets revealed that the predominant locations of H residing in CNS are sp2 hybridized C on surface and bulk. Fourthly, a fabricating process was developed to coat low work function ZrC on nanosheets for field emission enhancement. The carbide triple-peak in the AES spectra indicated that Zr carbide formed, but oxygen was not completely removed. The Zr(CxOy) coating was dispersed as nanobeads on the CNS surface. Although the work function was reduced, the coated CNS emission properties were not improved due to an increased beta factor. Further analysis suggest that for low emission current (<1 uA), the H adsorbates affect emission by altering the work function. In high emission current (>10 uA), thermal, ionic or electronic transition effects may occur, which differently affect the field emission process.
Zhao, Xin
Carbon Emission Capstone (title provided or enhanced by cataloger)
NSDL National Science Digital Library
There are two ways to reduce net emissions of carbon dioxide: limit how much carbon dioxide is emitted into the atmosphere as we burn fossil fuels, or increase the rate at which it is absorbed. In this lesson, discussion topics include the Kyoto Protocol and the use of carbon credits to reduce emissions of carbon dioxide into the atmosphere. Students can listen to a National Public Radio show that reports on new research that both illuminates and further complicates the picture of how the Earth is warming. The lesson includes an activity in which students examine their personal annual carbon emissions (calculated in the previous exercise) and determine how many trees it would take to sequester these emissions. They will then extrapolate this number to the populations of their school campus and their county.
Pratte, John
Reducing Surfactant Adsorption in Carbonate Reservoirs
This paper compares the adsorption of anionic and cationic surfactants on carbonate minerals. It shows that, in general, cationic surfactants may exhibit significantly less adsorption on carbonate minerals than that exhibited by anionic surfactants. It is also shown that cationic surfactants adsorption on carbonates may be reduced dramatically by the presence of divalent cations, an environment in which the precipitation
Tabatabal Ahmadall; Marla Gonzalez; Jeffrey Harwell; John Scamehorn
Carbon emissions from tropical forest degradation caused by logging
NASA Astrophysics Data System (ADS)
The focus of land-use related efforts in developing countries to reduce carbon emissions has been on slowing deforestation, yet international agreements are to reduce emissions from both deforestation and forest degradation (REDD). The second ĹDĺ is poorly understood and accounted for a number of technical and policy reasons. Here we introduce a complete accounting method for estimating emission factors from selective timber harvesting, a substantial form of forest degradation in many tropical developing countries. The method accounts separately for emissions from the extracted log, from incidental damage to the surrounding forest, and from logging infrastructure, and emissions are expressed as units of carbon per cubic meter of timber extracted to allow for simple application to timber harvesting statistics. We applied the method in six tropical countries (Belize, Bolivia, Brazil, Guyana, Indonesia, and Republic of Congo), resulting in total emission factors of 0.99?2.33 Mg C m?3. In all cases, emissions were dominated by damage to surrounding vegetation and the infrastructure rather than the logs themselves, and total emissions represented about 3ľ15% of the biomass carbon stocks of the associated unlogged forests. We then combined the emission factors with country level logging statistics for nine key timber producing countries represented by our study areas to gain an understanding of the order of magnitude of emissions from degradation compared to those recently reported for deforestation in the same countries. For the nine countries included, emissions from logging were on average equivalent to about 12% of those from deforestation. For those nine countries with relatively low emissions from deforestation, emissions from logging were equivalent to half or more of those from deforestation, whereas for those countries with the highest emissions from deforestation, emissions from logging were equivalent to <10% of those from deforestation. Understanding how to account emissions and the magnitude of each emissions source resulting from tropical timber harvesting practices helps identify where there are opportunities to reduce emissions from the second ĹDĺ in REDD.
Pearson, Timothy R. H.; Brown, Sandra; Casarim, Felipe M.
Energy efficiency procedures for agricultural machinery used in onion cultivation (Allium fistulosum) as an alternative to reduce carbon emissions under the clean development mechanism at Aquitania (Colombia)
NASA Astrophysics Data System (ADS)
Climate change has both causes and consequences over agriculture. This paper focuses on the first element and presents scenarios for ASOLAGO -an onion cropper's association in Colombia with 250 members- to reduce their carbon footprint. It evaluates a case study at "La Primavera" farm using a methodology approved by the United Nations Framework Convention on Climate Change. Land preparation and crop irrigation were analyzed as stages in order to propose energy efficiency alternatives for both the farm and the association. They include field efficiency, fuel economy and energy efficiency from biofuels for the first stage as well as solar and wind energy supply for the second. A cost-benefit analysis to generate additional income selling additional power produced by the system to the National Grid was done.
Ochoa, K.; Carrillo, S.; Gutierrez, L.
Fossil fuel derivatives with reduced carbon. Phase I final report
This project involves the simultaneous production of clean fossil fuel derivatives with reduced carbon and sulfur, along with value-added carbon nanofibers. This can be accomplished because the nanofiber production process removes carbon via a catalyzed pyrolysis reaction, which also has the effect of removing 99.9% of the sulfur, which is trapped in the nanofibers. The reaction is mildly endothermic, meaning that net energy production with real reductions in greenhouse emissions are possible. In Phase I research, the feasibility of generating clean fossil fuel derivatives with reduced carbon was demonstrated by the successful design, construction and operation of a facility capable of utilizing coal as well as natural gas as an inlet feedstock. In the case of coal, for example, reductions in CO{sub 2} emissions can be as much as 70% (normalized according to kilowatts produced), with the majority of carbon safely sequestered in the form of carbon nanofibers or coke. Both of these products are value-added commodities, indicating that low-emission coal fuel can be done at a profit rather than a loss as is the case with most clean-up schemes. The main results of this project were as follows: (1) It was shown that the nanofiber production process produces hydrogen as a byproduct. (2) The hydrogen, or hydrogen-rich hydrocarbon mixture can be consumed with net release of enthalpy. (3) The greenhouse gas emissions from both coal and natural gas are significantly reduced. Because coal consumption also creates coke, the carbon emission can be reduced by 75% per kilowatt-hour of power produced.
Kennel, E.B.; Zondlo, J.W.; Cessna, T.J.
Hydrocarbon and carbon monoxide emissions from biomass burning in Brazil
Field measurements of hydrocarbon emissions from biomass burning in the cerrado (grasslands) and selva (tropical forest) regions of Brazil in 1979 and 1980 are characterized and quantified here. Regional consequences of burning activities include increased background mixing ratios of carbon monoxide and ozone, as well as reduced visibility, over extensive areas. Global extrapolation of the emission rate of hydrocarbons from
J. P. Greenberg; P. R. Zimmerman; L. Heidt; W. Pollock
Reducing GHG emissions in the United States' transportation sector
Reducing GHG emissions in the U.S. transportation sector requires both the use of highly efficient propulsion systems and low carbon fuels. This study compares reduction potentials that might be achieved in 2060 for several advanced options including biofuels, hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and fuel cell electric vehicles (FCEV), assuming that technical and cost reduction targets are met and necessary fueling infrastructures are built. The study quantifies the extent of the reductions that can be achieved through increasing engine efficiency and transitioning to low-carbon fuels separately. Decarbonizing the fuels is essential for achieving large reductions in GHG emissions, and the study quantifies the reductions that can be achieved over a range of fuel carbon intensities. Although renewables will play a vital role, some combination of coal gasification with carbon capture and sequestration, and/or nuclear energy will likely be needed to enable very large reductions in carbon intensities for hydrogen and electricity. Biomass supply constraints do not allow major carbon emission reductions from biofuels alone; the value of biomass is that it can be combined with other solutions to help achieve significant results. Compared with gasoline, natural gas provides 20% reduction in GHG emissions in internal combustion engines and up to 50% reduction when used as a feedstock for producing hydrogen or electricity, making it a good transition fuel for electric propulsion drive trains. The material in this paper can be useful information to many other countries, including developing countries because of a common factor: the difficulty of finding sustainable, low-carbon, cost-competitive substitutes for petroleum fuels.
Das, Sujit [ORNL; Andress, David A [ORNL; Nguyen, Tien [U.S. DOE
Structuring economic incentives to reduce emissions from deforestation within Indonesia
We estimate and map the impacts that alternative national and subnational economic incentive structures for reducing emissions from deforestation (REDD+) in Indonesia would have had on greenhouse gas emissions and national and local revenue if they had been in place from 2000 to 2005. The impact of carbon payments on deforestation is calibrated econometrically from the pattern of observed deforestation and spatial variation in the benefits and costs of converting land to agriculture over that time period. We estimate that at an international carbon price of $10/tCO2e, a ômandatory incentive structure,ö such as a cap-and-trade or symmetric tax-and-subsidy program, would have reduced emissions by 163ľ247 MtCO2e/y (20ľ31% below the without-REDD+ reference scenario), while generating a programmatic budget surplus. In contrast, a ôbasic voluntary incentive structureö modeled after a standard payment-for-environmental-services program would have reduced emissions nationally by only 45ľ76 MtCO2e/y (6ľ9%), while generating a programmatic budget shortfall. By making four policy improvementsŚpaying for net emission reductions at the scale of an entire district rather than site-by-site; paying for reductions relative to reference levels that match business-as-usual levels; sharing a portion of district-level revenues with the national government; and sharing a portion of the national government's responsibility for costs with districtsŚan ôimproved voluntary incentive structureö would have been nearly as effective as a mandatory incentive structure, reducing emissions by 136ľ207 MtCO2e/y (17ľ26%) and generating a programmatic budget surplus.
Busch, Jonah; Lubowski, Ruben N.; Godoy, Fabiano; Steininger, Marc; Yusuf, Arief A.; Austin, Kemen; Hewson, Jenny; Juhn, Daniel; Farid, Muhammad; Boltz, Frederick
Towards real energy economics: Energy policy driven by life-cycle carbon emission
Alternative energy technologies (AETs) have emerged as a solution to the challenge of simultaneously meeting rising electricity demand while reducing carbon emissions. However, as all AETs are responsible for some greenhouse gas (GHG) emissions during their construction, carbon emission ôPonzi Schemesö are currently possible, wherein an AET industry expands so quickly that the GHG emissions prevented by a given technology
R. Kenny; C. Law; J. M. Pearce
Aluminum: Reducing chloride emissions from aluminum production
Reynolds Metals Company (RMC), with assistance from a NICE{sup 3} grant, is developing for commercialization a closed-loop control process that greatly reduces chlorine emissions and increases plant efficiency while maintaining metal quality. The process still utilizes chlorine to remove impurities during aluminum processing, but is more effective than current methods. With the new technology chlorine in the stack is monitored and input chlorine is adjusted continuously. This optimization of chlorine use results in substantially less waste because less chlorine has to be bought or produced by aluminum manufacturers. This innovation is a significant improvement over conventional aluminum treatments, in which chlorine is injected in a more costly and wasteful manner. By the year 2010, the new technology has the potential to reduce the energy it takes to create chlorine by 8.4 billion Btu per year and to cut greenhouse gas emissions by 1,377 tons per year.
Simon, P.
Carbon emissions and sequestration potential of Central African ecosystems.
Joint Implementation under the Climate Change Convention and Clean Development Mechanism of the Kyoto Protocol require a scientific understanding of current carbon stocks, fluxes, and sequestration potential, especially in tropical ecosystems where there are large carbon reservoirs, significant carbon emissions, and large land areas available for reforestation. Central Africa contains 10% of the world's remaining tropical moist forests and has received little attention in carbon studies. In 1980, above-ground carbon stocks in the central African ecosystem were 28.92 Pg and were reduced to 24.79 Pg by 1990. Improved forest management aimed at increasing biomass density could sequester 18.32 Pg of carbon, and over 500,000 km2 formerly forested land will be available by 2050 for reforestation with a capacity to offset 10 Pg carbon. Understanding the spatial distribution of biomass carbon and sequestration potential will be essential for carbon trading initiatives through Joint Implementation and Clean Development Mechanism. PMID:11757283
Zhang, Q; Justice, C O
Reduced Martian Carbon: Evidence from Martian Meteorites
NASA Technical Reports Server (NTRS)
Identification of indigenous reduced carbon species on Mars has been a challenge since the first hypotheses about life on Mars were proposed. Ranging from the early astronomical measurements to analyses of samples from the Martian surface in the form of Martian meteorites. The first direct attempt to analyze the carbon species on the surface was in 1976 with the Viking GC-MS in-situ experiment which gave inconclusive results at two sites on Mars [1]. With the recognition in 1983 that samples of the Martian surface were already present on Earth in the form of Martian meteorites by Bogard and Johnson [2] new opportunities became available for direct study of Mars's samples in te rlraesbtrioalratories. Carbon isotopic compositional information suggested a reduced carbon component was present in the Martian meteorites [3-5]. Polycyclic aromatic hydrocarbons associated with carbonate globules in ALH84001 were later identified [6,7]. Jull et al [8] noted that an insoluble component was present within Nakhla and more than 75% of its C lacked any 14C, which is modern-day carbon contaminant. This carbon fraction was believed to be either indigenous (i..e. Martian) or ancient meteoritic carbon phase. Within the fractures of Nakhla and ALH84001, Fisk et al [9,10] identified reduced carbon-enriched areas. Gibson et al. [11] using a combination of NanoSIMS, Focused Electron microscopy, Laser Raman Spectroscopy and Stepped-Combustion Static Mass Spectrometry analyses the presence of possible indigenous reduced carbon components within the 1.3 Ga old Nakhla.
Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, SImon J.; Pillinger, COlin T.; Wright, Ian P.; Verchovsky, A. P.
Opportunities for reducing greenhouse gas emissions in tropical peatlands
The upcoming global mechanism for reducing emissions from deforestation and forest degradation in developing countries should include and prioritize tropical peatlands. Forested tropical peatlands in Southeast Asia are rapidly being converted into production systems by introducing perennial crops for lucrative agribusiness, such as oil-palm and pulpwood plantations, causing large greenhouse gas (GHG) emissions. The Intergovernmental Panel on Climate Change Guidelines for GHG Inventory on Agriculture, Forestry, and Other Land Uses provide an adequate framework for emissions inventories in these ecosystems; however, specific emission factors are needed for more accurate and cost-effective monitoring. The emissions are governed by complex biophysical processes, such as peat decomposition and compaction, nutrient availability, soil water content, and water table level, all of which are affected by management practices. We estimate that total carbon loss from converting peat swamp forests into oil palm is 59.4á▒á10.2áMg of CO2 per hectare per year during the first 25áy after land-use cover change, of which 61.6% arise from the peat. Of the total amount (1,486á▒á183áMg of CO2 per hectare over 25áy), 25% are released immediately from land-clearing fire. In order to maintain high palm-oil production, nitrogen inputs through fertilizer are needed and the magnitude of the resulting increased N2O emissions compared to CO2 losses remains unclear.
Murdiyarso, D.; Hergoualc'h, K.; Verchot, L. V.
Opportunities for reducing greenhouse gas emissions in tropical peatlands.
The upcoming global mechanism for reducing emissions from deforestation and forest degradation in developing countries should include and prioritize tropical peatlands. Forested tropical peatlands in Southeast Asia are rapidly being converted into production systems by introducing perennial crops for lucrative agribusiness, such as oil-palm and pulpwood plantations, causing large greenhouse gas (GHG) emissions. The Intergovernmental Panel on Climate Change Guidelines for GHG Inventory on Agriculture, Forestry, and Other Land Uses provide an adequate framework for emissions inventories in these ecosystems; however, specific emission factors are needed for more accurate and cost-effective monitoring. The emissions are governed by complex biophysical processes, such as peat decomposition and compaction, nutrient availability, soil water content, and water table level, all of which are affected by management practices. We estimate that total carbon loss from converting peat swamp forests into oil palm is 59.4 ▒ 10.2 Mg of CO(2) per hectare per year during the first 25 y after land-use cover change, of which 61.6% arise from the peat. Of the total amount (1,486 ▒ 183 Mg of CO(2) per hectare over 25 y), 25% are released immediately from land-clearing fire. In order to maintain high palm-oil production, nitrogen inputs through fertilizer are needed and the magnitude of the resulting increased N(2)O emissions compared to CO(2) losses remains unclear. PMID:21081702
Murdiyarso, D; Hergoualc'h, K; Verchot, L V
Degassing of reduced carbon from planetary basalts.
Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential. PMID:23569260
Wetzel, Diane T; Rutherford, Malcolm J; Jacobsen, Steven D; Hauri, Erik H; Saal, Alberto E
Degassing of reduced carbon from planetary basalts
Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential.
Wetzel, Diane T.; Rutherford, Malcolm J.; Jacobsen, Steven D.; Hauri, Erik H.; Saal, Alberto E.
Health and Climate Change 3 Public health benefits of strategies to reduce greenhouse-gas emissions: low-carbon electricity generation
In this report, the third in this Series on health and climate change, we assess the changes in particle air pollution emissions and consequent effects on health that are likely to result from greenhouse-gas mitigation measures in the electricity generation sector in the European Union (EU), China, and India. We model the effect in 2030 of policies that aim to
Anil Markandya; Ben G Armstrong; Simon Hales; Aline Chiabai; Patrick Criqui; Silvana Mima; Cathryn Tonne; Paul Wilkinson
Reducing Indoor Air Emissions from Dry-Process Photocopy Machines.
National Technical Information Service (NTIS)
The paper discusses reducing indoor air emissions from dry-process photocopy machines. These emissions include: volatile organic compounds (VOCs), ozone, and particles. By measuring emissions in a large test chamber, reviewing the literature, and interact...
K. W. Leovic C. M. Northeim J. A. Calcagni L. S. Sheldon D. A. Whitaker
Reducing fuel subsidy or taxing carbon? Comparing the two instruments from the economy, environment, and equity perspective for Indonesia
Reducing fuel subsidy and taxing carbon have a tendency toward reducing energy consumption and carbon emissions. However, both instruments may have differing impacts in their magnitudes of the emissions reduction and on the economy as a whole. Using INDONESIA-E3 (Economy-Equity-Environment) model, a computable general equilibrium (CGE) model which includes carbon emissions, carbon taxation, as well as, strong feature in distributional
Arief Anshory Yusuf; Arief Ramayandi
Reducing greenhouse gas emissions for climate stabilization: framing regional options
The Intergovernmental Panel on Climate Change (IPCC) has stated that stabilizing atmospheric CO{sub 2} concentrations will require reduction of global greenhouse gas (GHG) emissions by as much as 80% by 2050. Subnational efforts to cut emissions will inform policy development nationally and globally. We projected GHG mitigation strategies for Minnesota, which has adopted a strategic goal of 80% emissions reduction by 2050. A portfolio of conservation strategies, including electricity conservation, increased vehicle fleet fuel efficiency, and reduced vehicle miles traveled, is likely the most cost-effective option for Minnesota and could reduce emissions by 18% below 2005 levels. An 80% GHG reduction would require complete decarbonization of the electricity and transportation sectors, combined with carbon capture and sequestration at power plants, or deep cuts in other relatively more intransigent GHG-emitting sectors. In order to achieve ambitious GHG reduction goals, policymakers should promote aggressive conservation efforts, which would probably have negative net costs, while phasing in alternative fuels to replace coal and motor gasoline over the long-term. 31 refs., 3 figs., 1 tab.
Laura Schmitt Olabisi; Peter B. Reich; Kris A. Johnson; Anne R. Kapuscinski; Sangwon Suh; Elizabeth J. Wilson [University of Minnesota, Saint Paul, MN (United States). Ecosystem Science and Sustainability Initiative
Reducing VOC Press Emission from OSB Manufacturing
Current regulations require industry to meet air emission standards with regard to particulates, volatile organic compounds (VOCs), hazardous air pollutants (HAPs) and other gases. One of many industries that will be affected by the new regulations is the wood composites industry. This industry generates VOCs, HAPs, and particulates mainly during the drying and pressing of wood. Current air treatment technologies for the industry are expensive to install and operate. As regulations become more stringent, treatment technologies will need to become more efficient and cost effective. The overall objective of this study is to evaluate the use of process conditions and chemical additives to reduce VOC/HAPs in air emitted from presses and dryers during the production of oriented strand board.
Dr. Gary D. McGinnis; Laura S. WIlliams; Amy E. Monte; Jagdish Rughani: Brett A. Niemi; Thomas M. Flicker
Australian climate-carbon cycle feedback reduced by soil black carbon
Annual emissions of carbon dioxide from soil organic carbon are an order of magnitude greater than all anthropogenic carbon dioxide emissions taken together. Global warming is likely to increase the decomposition of soil organic carbon, and thus the release of carbon dioxide from soils, creating a positive feedback. Current models of global climate change that recognize this soil carbon feedback
Johannes Lehmann; Jan Skjemstad; Saran Sohi; John Carter; Michele Barson; Pete Falloon; Kevin Coleman; Peter Woodbury; Evelyn Krull
Historical and future carbon emissions from croplands
NASA Astrophysics Data System (ADS)
We examine past and future carbon emissions from global croplands, considering land-use change, changes in crop productivity, tillage practices, and residue removal. We find that emissions over the historical period are sensitive to the assumed productivity of arable land that is not planted in a given year and the assumed fraction of soil carbon that is released during land conversion. The role of this "other" arable land, both at present and over the historical period, is not well understood and should be examined further. The carbon balance of croplands over 21st century depends on changes in management practices, particularly the adoption of conservation tillage and the potential removal of residue for use as energy feedstocks. We find that croplands will not become large carbon sinks in the future, however, unless most crop residue is left on fields. Given the relatively low carbon "penalty" incurred by removal, residue use for energy feedstocks may be the preferred option.
Smith, S. J.
Allowable carbon emissions lowered by multiple climate targets.
Climate targets are designed to inform policies that would limit the magnitude and impacts of climate change caused by anthropogenic emissions of greenhouse gases and other substances. The target that is currently recognized by most world governments places a limit of two degrees Celsius on the global mean warming since preindustrial times. This would require large sustained reductions in carbon dioxide emissions during the twenty-first century and beyond. Such a global temperature target, however, is not sufficient to control many other quantities, such as transient sea level rise, ocean acidification and net primary production on land. Here, using an Earth system model of intermediate complexity (EMIC) in an observation-informed Bayesian approach, we show that allowable carbon emissions are substantially reduced when multiple climate targets are set. We take into account uncertainties in physical and carbon cycle model parameters, radiative efficiencies, climate sensitivity and carbon cycle feedbacks along with a large set of observational constraints. Within this framework, we explore a broad range of economically feasible greenhouse gas scenarios from the integrated assessment community to determine the likelihood of meeting a combination of specific global and regional targets under various assumptions. For any given likelihood of meeting a set of such targets, the allowable cumulative emissions are greatly reduced from those inferred from the temperature target alone. Therefore, temperature targets alone are unable to comprehensively limit the risks from anthropogenic emissions. PMID:23823728
Steinacher, Marco; Joos, Fortunat; Stocker, Thomas F
Managing Restored Wetlands in the Sacramento-San Joaquin Delta to Reduce Methane Emissions and Increase Carbon Uptake Laurie Koteen, Sara Knox, Cove Sturtevant, Joseph Verfaillie, Jaclyn Hatala, Dennis Baldocchi
NASA Astrophysics Data System (ADS)
The Sacramento-San Joaquin Delta of California is a region transformed by more than a century of agricultural practices. Beginning in the 19th century, substantial regions were first drained of water and then converted to cropland in order to take advantage of the area's rich peatland soils. In the intervening time period, soil oxidation and subsidence have led to huge peat losses of up to 10 m in some places, and river water now threatens to topple the levees that were erected to keep fields from flooding. Within this region, we have been monitoring greenhouse gas exchange of several agricultural sites, a degraded pasture, and two restored wetlands. Of these land use types, restoration of wetlands is of particular interest to Delta managers as these sites attain many of the region's most pressing ecological goals, including improved water quality, increased wildlife habitat, and soil accretion. In our current investigation, we hope to assess if wetland management activities can be implemented to achieve greenhouse gas management goals as well. While we find that the restored wetlands are able to take up and store a substantial amount of carbon via rapid growth rates, they also emit methane; a greenhouse gas 25 times more potent than COČ2. We are currently in the process of implementing two management activities with the goals of reducing methane emissions and increasing carbon uptake. Evidence from the wetland literature indicates that periodic lowering of the water table below the soil surface can reduce wetland methane emissions by: 1. Reintroducing oxygen into the soil column. This both supports growth of the methanotrophic bacteria that consume methane produced in the anaerobic zones of the soil column, and suppresses the methanogens that produce it. 2. Re-oxidization of formerly reduced compounds in the soil, (i.e. NO3-, SO42-) which can serve as alternative terminal electron acceptors of the decomposition byproducts (i.e. H2 and acetate) that lead to methane formation. Under these conditions, it becomes more energetically favorable for alternative chemical transformations to occur in which CO2 and not CH4Č is released. A second management activity would be implemented to see if wetland carbon uptake could be increased. As wetlands mature, perennial wetland vegetation often develops a significant thatch layer which can reduce photosynthesis of growing shoots by blocking radiation from leaf surfaces. Here we propose to remove the stalks of established vegetation. This would serve two goals: 1. Decomposing vegetation would be incorporated into the soil, leading to soil accretion, and 2. Thatch removal would liberate fledgling shoots, potentially increasing carbon uptake through subsequent seasons. A third investigation would compare CO2 and CH4 fluxes at an existing tower atop low salinity sediments with a new tower where site salinity is relatively high. This effort would inform new site selection efforts for wetland restoration projects. Sites located closer to the San Francisco Bay Area are tidally-influenced, and therefore have higher salinity than the impounded freshwater systems of our current study within the Delta region.
Koteen, L. E.; Knox, S. H.; Sturtevant, C. S.; Verfaillie, J. G.; Matthes, J. H.; Baldocchi, D. D.
Cumulative carbon emissions, emissions floors and short-term rates of warming: implications for policy.
A number of recent studies have found a strong link between peak human-induced global warming and cumulative carbon emissions from the start of the industrial revolution, while the link to emissions over shorter periods or in the years 2020 or 2050 is generally weaker. However, cumulative targets appear to conflict with the concept of a 'floor' in emissions caused by sectors such as food production. Here, we show that the introduction of emissions floors does not reduce the importance of cumulative emissions, but may make some warming targets unachievable. For pathways that give a most likely warming up to about 4░C, cumulative emissions from pre-industrial times to year 2200 correlate strongly with most likely resultant peak warming regardless of the shape of emissions floors used, providing a more natural long-term policy horizon than 2050 or 2100. The maximum rate of CO(2)-induced warming, which will affect the feasibility and cost of adapting to climate change, is not determined by cumulative emissions but is tightly aligned with peak rates of emissions. Hence, cumulative carbon emissions to 2200 and peak emission rates could provide a clear and simple framework for CO(2) mitigation policy. PMID:21115512
Bowerman, Niel H A; Frame, David J; Huntingford, Chris; Lowe, Jason A; Allen, Myles R
New insights into the interactions between carbon dioxide and ammonia emissions during sewage sludge composting.
This study aimed to investigate the role of carbon dioxide in reducing ammonia emissions. Three variations of a composting experiment were conducted in a laboratory-scale reactor, all of which exhibited the three typical composting phases. Approximately 70% of the ammonia emissions occurred within 96-144 h of the thermophilic stage. The maximum rate of change for the carbon dioxide emissions occurred at different times for different carbon source types, mixing rates, and addition times. The rate of change and total concentration of emitted carbon dioxide played a crucial role in ammonia emission due to their relationship to the intensity of ammonia assimilation. The addition of a carbon source that could be utilized by thermophilic microorganisms stimulated ammonia assimilation and thus reduced ammonia emissions. These findings suggested that the addition of a 7:3 mixture of sucrose and straw powder at 108 h is suitable for reducing ammonia emissions. PMID:23567706
Li, Yunbei; Li, Weiguang; Wu, Chuandong; Wang, Ke
A performance standards approach to reducing CO{sub 2} emissions from electric power plants
The CO{sub 2} emission performance standard policies outlined in this paper could complement a cap-and-trade program that puts a price on carbon and serve to significantly reduce the CO{sub 2} emissions from coal use for electricity generation. Emission performance standards have a long history in the United States and have been successfully used to control emissions of various air pollutants from electric generators. This paper explores the rationale for using emission performance standards and describes the various types of performance standard policies. Emission performance standards that address CO{sub 2} emissions could promote the deployment of carbon capture and storage technology coupled with new and existing coal-fueled electric power plants. 28 refs., 4 figs., 4 tabs.
Rubin, E.S. [Carnegie Mellon University, Pittsburgh, PA (United States)
Global demographic trends and future carbon emissions
Substantial changes in population size, age structure, and urbanization are expected in many parts of the world this century. Although such changes can affect energy use and greenhouse gas emissions, emissions scenario analyses have either left them out or treated them in a fragmentary or overly simplified manner. We carry out a comprehensive assessment of the implications of demographic change for global emissions of carbon dioxide. Using an energyľeconomic growth model that accounts for a range of demographic dynamics, we show that slowing population growth could provide 16ľ29% of the emissions reductions suggested to be necessary by 2050 to avoid dangerous climate change. We also find that aging and urbanization can substantially influence emissions in particular world regions.
O'Neill, Brian C.; Dalton, Michael; Fuchs, Regina; Jiang, Leiwen; Pachauri, Shonali; Zigova, Katarina
Carbon footprint and ammonia emissions of California beef production systems.
Beef production is a recognized source of greenhouse gas (GHG) and ammonia (NH(3)) emissions; however, little information exists on the net emissions from beef production systems. A partial life cycle assessment (LCA) was conducted using the Integrated Farm System Model (IFSM) to estimate GHG and NH(3) emissions from representative beef production systems in California. The IFSM is a process-level farm model that simulates crop growth, feed production and use, animal growth, and the return of manure nutrients back to the land to predict the environmental impacts and economics of production systems. Ammonia emissions are determined by summing the emissions from animal housing facilities, manure storage, field applied manure, and direct deposits of manure on pasture and rangeland. All important sources and sinks of methane, nitrous oxide, and carbon dioxide are predicted from primary and secondary emission sources. Primary sources include enteric fermentation, manure, cropland used in feed production, and fuel combustion. Secondary emissions occur during the production of resources used on the farm, which include fuel, electricity, machinery, fertilizer, and purchased animals. The carbon footprint is the net exchange of all GHG in carbon dioxide equivalent (CO(2)e) units per kg of HCW produced. Simulated beef production systems included cow-calf, stocker, and feedlot phases for the traditional British beef breeds and calf ranch and feedlot phases for Holstein steers. An evaluation of differing production management strategies resulted in ammonia emissions ranging from 98 ▒ 13 to 141 ▒ 27 g/kg HCW and carbon footprints of 10.7 ▒ 1.4 to 22.6 ▒ 2.0 kg CO(2)e/kg HCW. Within the British beef production cycle, the cow-calf phase was responsible for 69 to 72% of total GHG emissions with 17 to 27% from feedlot sources. Holstein steers that entered the beef production system as a by-product of dairy production had the lowest carbon footprint because the emissions associated with their mothers were primarily attributed to milk rather than meat production. For the Holstein system, the feedlot phase was responsible for 91% of the total GHG emission, while the calf-ranch phase was responsible for 7% with the remaining 2% from transportation. This simulation study provides baseline emissions data for California beef production systems and indicates where mitigation strategies can be most effective in reducing emissions. PMID:22952361
Stackhouse-Lawson, K R; Rotz, C A; Oltjen, J W; Mitloehner, F M
Economic instruments for mitigating carbon emissions: scaling up carbon finance in Chinaĺs buildings sector
The relevance and cost-effectiveness are key criteria for policymakers to select appropriate policy and economic instruments\\u000a for reducing carbon emissions. Here we assess the applicability of carbon finance instruments for the improvement in building\\u000a energy efficiency by adopting the high efficiency standards as well as advanced energy supply systems, building on a case\\u000a study in a northern city in China.
Jun Li; Michel Colombier
Policy Planning to Reduce Greenhouse Gas Emissions
NSDL National Science Digital Library
Preceded by the State Workbook: Methodologies for Estimating Greenhouse Gas Emissions, this document by the Environmental Protection Agency (EPA) serves to guide states in "identifying and evaluating options to mitigate emissions" affecting global climate change. Each of the report's three parts details climate change and policy options. Part one discusses the Initiation of Climate Change Programs. Part two describes sources of emissions and potential policy options. Part three completes the report by offering "guidance in preparing the State Action Plan." Appendices supply a glossary, references, state plans, and a specific example reduction plan.
Agency., United S.
Reduced Future Precipitation Makes Permanence of Amazonian Carbon Sinks Questionable
NASA Astrophysics Data System (ADS)
The tropical forests of the Amazon, considered as a tipping element in Earth's climate system, provide several ecosystem services including the maintenance of favourable regional climatic conditions in the region and storage of large amounts of carbon in their above- and below-ground pools. While it is nearly impossible, at present, to put a dollar value on these ecosystem services, the developed countries have started paying large sums of money to developing countries in the tropics to reduce deforestation. Norway recently committed up to $1 billion to the Amazon fund. The United Nations' Reducing Emissions from Deforestation and forest Degradation (REDD) program also financially supports national activities of 13 countries worldwide. The primary assumption inherent in paying for avoiding deforestation is that avoided land use change emissions contribute towards climate change mitigation. In addition, the standing forests that are spared deforestation contribute towards additional carbon sinks associated with the CO2 fertilization effect. Implicit in this reasoning is the understanding that the carbon sinks provided by avoided deforestation have some "permanence" associated with them, at least in the order of 50-100 years. Clearly, if "avoided deforestation" is essentially "delayed deforestation" then the benefits will not be long lasting. More importantly, changes in climate have the potential to adversely affect the permanence of carbon sinks, whether they are being paid for or not. This presentation will address the question of "permanence" by analyzing simulations of the second generation Canadian Earth system model (CanESM2) that are contributing results to the upcoming fifth Coupled Modeled Intercomparison Project (CMIP5). CanESM2 results for the future RCP 2.6, 4.5 and 8.5 scenarios show, that due to reduced future precipitation, the Amazonian region remains a net source of carbon over the 21st century in all scenarios. The carbon losses during the recent 2005 and 2010 droughts in the Amazonian region nearly wiped away the gains made during a decade indicating that the era of intact Amazonian forests acting as carbon sinks may be over. CanESM2 simulations imply that the future of the Amazonian region may look more like these drought years, suggesting that the future reduced precipitation over the region can indeed "tip over" the Amazonian forests.
Arora, V.
An approach to a black carbon emission inventory for Mexico by two methods.
A black carbon (BC) emission inventory for Mexico is presented. Estimate was performed by using two approaches, based on fuel consumption and emission factors in a top-down scheme, and the second from PM25 emission data and its correlation with black carbon by source category, assuming that black carbon=elemental carbon. Results show that black carbon emissions are in interval 53-473Gg using the fuel consumption approach and between 62 and 89 using the sector method. Black carbon key sources come from biomass burning in the rural sector, with 47 percent share to the National total. Mobile sources emissions account to 16% to the total. An opportunity to reduce, in the short-term, carbon dioxide equivalent (CO2-eq) emissions by reducing black carbon emissions would be obtained in reducing emissions mainly from biomass burning in rural housing sector and diesel emissions in the transport sector with important co-benefits in direct radiative forcing, public health and air quality. PMID:24561296
Cruz-N˙˝ez, Xochitl
Opportunities to reduce greenhouse gas emissions from households in Nigeria
Efforts to mitigate climate threats should not exclude the household as the household is a major driver of greenhouse gas\\u000a (GHG) emissions through its consumption patterns. This paper derives an emission index that could be used to estimate inventories\\u000a of carbon dioxide (CO2) emissions from kerosene combustion for lighting in Nigeria and also looks at the implications of solar pv
O. Adeoti; S. O. Osho
The Land Use Planning Imperative: Applying Carbon Emissions Analyses
NASA Astrophysics Data System (ADS)
Reversing global warming is the defining crisis of the 21st century and must be dealt with, in part, by reinventing the built environment. Current land use and planning frameworks are not aligned with scientific models which can aid in the reversal of carbon emissions at the local and regional scale. The disjunction between land use planning and the scientific methodologies for calculating the impacts of climate change beg for a stronger union between climate change science and land use planning. Buildings account for approximately 35 percent of the U.S. carbon emissions while the transportation sector accounts for approximately 27 percent (U.S. Department of Energy, Energy Information Administration, United States Environmental Protection Agency, 2007). To adopt energy efficiency measures and hence reduce carbon dioxide emissions at a site, city, or regional scale, land use planners and climate scientists must integrate their expertise to influence policy with precision and accuracy. Land use planners have influence over the design of the built environment in municipalities and institutions such as colleges and universities. In many ways, college and university campuses are microcosms of the land use patterns established historically; they demonstrate a lack of coordinated land use planning across the entire continent that is extremely dependent on the automobile and fossil fuels. Climate models predict that the average temperature at the Earth's surface could increase from 2.5 to 10.4║F above 1990 levels by the end of this century (United States Environmental Protection Agency, 2007). Further, it is estimated that the country will have to construct an additional 213 billion square feet of built space by the year 2030 to accommodate the increasing population. Planning and design will dictate the degree to which land use change will exacerbate trends of global warming. It commands an integration of the methodology to calculate carbon emissions with the science which demonstrates the impact of those emissions. This session presents a new approach and methodology for integrating calculating carbon emissions and land use planning to increase the accessibility of carbon dioxide emissions data, transforming our conception of how the built environment can function in a more sustainable way. The emergence of the public and institutional interest in reducing carbon emissions advances the question of how climate science may be applied and translated for a public audience to develop effective, measurable carbon reduction strategies. Building on the growing momentum in the higher education sector in the United States, land use planners are grappling with the integration of carbon reduction and the transformation of the built environment, particularly at college campuses. A critical first step in reducing carbon emissions is to complete a greenhouse gas inventory. In recent years, universities have adopted challenges to become climate neutral through operations, buildings, and transportation. This session will present two case studies at universities of how land use planning integrates scientific data and suggested methodology from the IPCC, the Chicago Climate Exchange, the Kyoto Protocol, and various other climate action registries in order to demonstrate a university's contribution to global warming. By developing a methodology for calculating CO2 emissions, land use planning and climate science can collectively formulate strategies for a more sustainable future.
Bray, E. N.; Havens, G.
A Simple Evaluation Method for Annual CO2 Emissions Reduced by Distribution Loss Minimization
NASA Astrophysics Data System (ADS)
Global warming caused by carbon dioxide (CO2) and other greenhouse gases is one of the serious environmental issues. Carbon dioxide is the biggest contributor to global warming. Many efforts to reduce emissions of CO2 are carrying out in various fields. In electrical power system field, various approaches to reduce CO2 emissions have been performed such as loss reduction, utilization of renewable energy, recycling of resources and so on. Especially, distribution loss minimization is effective to reduce CO2 emissions because reduction of distribution loss leads to save the energy. For example, the largest distribution system in Japan consists of about 19,000 feeders. Much CO2 emissions can be reduced by minimizing distribution loss of the largest distribution system. However, CO2 emissions reduced by distribution loss minimization for the largest Japanese distribution system have not been estimated so far. In this paper, the authors try to calculate annual CO2 emissions reduced by distribution loss minimization for a distribution system model based on partial actual data, which is composed by 19,000 distribution feeders, 95,358 sectionalizing switches and 73,849 load sections. In the trial calculation, reduced CO2 emissions are estimated by sequentially proceeding four procedures: (1) classification of distribution system model into several load areas, (2) determination of loss minimum configuration in each load area, (3) calculation of reduced annual distribution loss for each area, and (4) calculation of reduced annual CO2 emissions. As the result of the trial calculation, reduced annual CO2 emissions of 40 Î 106kg/year is estimated for the Japanese largest scaled 19,000 feeders distribution model.
Hayashi, Yasuhiro; Takano, Hirotaka; Matsuki, Junya; Yokoyama, Masao
Global civil aviation black carbon emissions.
Aircraft black carbon (BC) emissions contribute to climate forcing, but few estimates of BC emitted by aircraft at cruise exist. For the majority of aircraft engines the only BC-related measurement available is smoke number (SN)-a filter based optical method designed to measure near-ground plume visibility, not mass. While the first order approximation (FOA3) technique has been developed to estimate BC mass emissions normalized by fuel burn [EI(BC)] from SN, it is shown that it underestimates EI(BC) by >90% in 35% of directly measured cases (R(2) = -0.10). As there are no plans to measure BC emissions from all existing certified engines-which will be in service for several decades-it is necessary to estimate EI(BC) for existing aircraft on the ground and at cruise. An alternative method, called FOX, that is independent of the SN is developed to estimate BC emissions. Estimates of EI(BC) at ground level are significantly improved (R(2) = 0.68), whereas estimates at cruise are within 30% of measurements. Implementing this approach for global civil aviation estimated aircraft BC emissions are revised upward by a factor of ~3. Direct radiative forcing (RF) due to aviation BC emissions is estimated to be ~9.5 mW/m(2), equivalent to ~1/3 of the current RF due to aviation CO2 emissions. PMID:23844612
Stettler, Marc E J; Boies, Adam M; Petzold, Andreas; Barrett, Steven R H
Styrene emissions are coming under increasing study as the U.S. Environmental Protection Agency (EPA) develops maximum achievable control technology standards. During the manufacture of fiber-reinforced plastics/composites products, styrene, a volatile organic compound and a haz...
Biodegradable plastic reduces ammonia emission during composting
Ammonia is the greatest nuisance odor compound among the exhaust gases that evolve during the composting process, in which raw materials with high concentrations of nitrogen, such as wastewater sludge, are decomposed. In the present study, a reduction of NH3 emission during composting of wastewater sludge was tried by mixing biodegradable plastic into composting raw material. Biodegradable plastic acts as
K Nakasaki; A Ohtaki; H Takano
Implementation of Emission Trading in Carbon Dioxide Sequestration Optimization Management
NASA Astrophysics Data System (ADS)
As an effective mid- and long- term solution for large-scale mitigation of industrial CO2 emissions, CO2 capture and sequestration (CCS) has been paid more and more attention in the past decades. A general CCS management system has complex characteristics of multiple emission sources, multiple mitigation technologies, multiple sequestration sites, and multiple project periods. Trade-off exists among numerous environmental, economic, political, and technical factors, leading to varied system features. Sound decision alternatives are thus desired for provide decision supports for decision makers or managers for managing such a CCS system from capture to the final geologic storage phases. Carbon emission trading has been developed as a cost-effective tool for reducing the global greenhouse gas emissions. In this study, a carbon capture and sequestration optimization management model is proposed to address the above issues. The carbon emission trading is integrated into the model, and its impacts on the resulting management decisions are analyzed. A multi-source multi-period case study is provided to justify the applicability of the modeling approach, where uncertainties in modeling parameters are also dealt with.
Zhang, X.; Duncan, I.
Spatial and Temporal Patterns in Carbon Emissions to the Atmosphere
NASA Astrophysics Data System (ADS)
Data on global fossil-fuel emissions of CO2 to the atmosphere for year 2000 show that the range of national average per capita emissions, in metric tons of carbon per person, includes values of 5.40 for the United States, 2.61 for Germany, 0.29 for India and 0.04 for Liberia. This range is more than two orders of magnitude. Similar data on national fossil-fuel emissions for the United States vary by more than an order of magnitude, from 34.18 metric tons of carbon per person for Wyoming to 2.70 for California. The state data also show differing patterns of change over time. The Kyoto Protocol would require ratifying developed countries to reduce greenhouse gas emissions to quantified negotiated targets. The concept of contraction and convergence (C&C) has been widely touted as a possible basis for ultimate, more strict limits on greenhouse gas emissions. The idea of C&C is that per-capita emissions of CO2 for all countries would converge toward some common value that is consistent with stabilization of global climate. The U.S., on the other hand, has proposed intensity-based emissions targets whereby goals would be defined in terms of emissions per unit of gross domestic product, or perhaps emissions per unit of output for specific activities. This paper describes the data set on U.S. CO2 emissions by state, and begins to explore the patterns between states and over time.
Broniak, C. T.; Blasing, T. J.; Marland, G.
High-resolution forest carbon stocks and emissions in the Amazon
Efforts to mitigate climate change through the Reduced Emissions from Deforestation and Degradation (REDD) depend on mapping and monitoring of tropical forest carbon stocks and emissions over large geographic areas. With a new integrated use of satellite imaging, airborne light detection and ranging, and field plots, we mapped aboveground carbon stocks and emissions at 0.1-ha resolution over 4.3 million ha of the Peruvian Amazon, an area twice that of all forests in Costa Rica, to reveal the determinants of forest carbon density and to demonstrate the feasibility of mapping carbon emissions for REDD. We discovered previously unknown variation in carbon storage at multiple scales based on geologic substrate and forest type. From 1999 to 2009, emissions from land use totaled 1.1% of the standing carbon throughout the region. Forest degradation, such as from selective logging, increased regional carbon emissions by 47% over deforestation alone, and secondary regrowth provided an 18% offset against total gross emissions. Very high-resolution monitoring reduces uncertainty in carbon emissions for REDD programs while uncovering fundamental environmental controls on forest carbon storage and their interactions with land-use change.
Asner, Gregory P.; Powell, George V. N.; Mascaro, Joseph; Knapp, David E.; Clark, John K.; Jacobson, James; Kennedy-Bowdoin, Ty; Balaji, Aravindh; Paez-Acosta, Guayana; Victoria, Eloy; Secada, Laura; Valqui, Michael; Hughes, R. Flint
Science at the Theater: Just say no to carbon emissions
April 26, 2010 Science at the Theater: Learn about three efforts our grandchildren may thank us for: cheap solar energy, bringing energy efficiency to China, and learning how to store carbon deep underground. Can solar energy be dirt cheap? We're all potentially billionaires when it comes to solar energy. The trick is learning how to convert sunlight to electricity using cheap and plentiful materials. Ramamoorthy Ramesh, an innovative materials scientist at Berkeley Lab, will discuss how he and other researchers are working to make photovoltaic cells using the most abundant elements in the Earth's crust -- materials that are literally as common as dirt. Energy efficiency in China Nan Zhou is a researcher with Berkeley Labs China Energy Group. She will speak about Chinas energy use and the policies that have been implemented to increase energy efficiency and reduce CO2 emission growth. Her work focuses on building China's capacity to evaluate, adopt and implement low-carbon development strategies. Zhou has an architecture degree from China, and a Master and Ph.D. in Engineering from Japan. Understanding geologic carbon sequestration Even with continued growth of renewable energy sources such as wind and solar, fossil fuels will likely remain cheap and plentiful for decades to come. Geologist Curt Oldenburg, who heads Berkeley Lab's Geologic Carbon Sequestration Program, will discuss a strategy to reduce carbon emissions from coal and natural gas. It involves pumping compressed CO2 captured from large stationary sources into underground rock formations that can store it for geological time scales.
Science at the Theater: Just say no to carbon emissions
April 26, 2010 Science at the Theater: Learn about three efforts our grandchildren may thank us for: cheap solar energy, bringing energy efficiency to China, and learning how to store carbon deep underground. Can solar energy be dirt cheap? We're all potentially billionaires when it comes to solar energy. The trick is learning how to convert sunlight to electricity using cheap and plentiful materials. Ramamoorthy Ramesh, an innovative materials scientist at Berkeley Lab, will discuss how he and other researchers are working to make photovoltaic cells using the most abundant elements in the Earth's crust -- materials that are literally as common as dirt. Energy efficiency in China Nan Zhou is a researcher with Berkeley Labs China Energy Group. She will speak about Chinas energy use and the policies that have been implemented to increase energy efficiency and reduce CO2 emission growth. Her work focuses on building China's capacity to evaluate, adopt and implement low-carbon development strategies. Zhou has an architecture degree from China, and a Master and Ph.D. in Engineering from Japan. Understanding geologic carbon sequestration Even with continued growth of renewable energy sources such as wind and solar, fossil fuels will likely remain cheap and plentiful for decades to come. Geologist Curt Oldenburg, who heads Berkeley Lab's Geologic Carbon Sequestration Program, will discuss a strategy to reduce carbon emissions from coal and natural gas. It involves pumping compressed CO2 captured from large stationary sources into underground rock formations that can store it for geological time scales.
Ramamoorthy Ramesh
Science at the Theater: Just say no to carbon emissions
April 26, 2010 Science at the Theater: Learn about three efforts our grandchildren may thank us for: cheap solar energy, bringing energy efficiency to China, and learning how to store carbon deep underground. Can solar energy be dirt cheap? We're all potentially billionaires when it comes to solar energy. The trick is learning how to convert sunlight to electricity using cheap and plentiful materials. Ramamoorthy Ramesh, an innovative materials scientist at Berkeley Lab, will discuss how he and other researchers are working to make photovoltaic cells using the most abundant elements in the Earth's crust -- materials that are literally as common as dirt. Energy efficiency in China Nan Zhou is a researcher with Berkeley Labs China Energy Group. She will speak about Chinas energy use and the policies that have been implemented to increase energy efficiency and reduce CO2 emission growth. Her work focuses on building China's capacity to evaluate, adopt and implement low-carbon development strategies. Zhou has an architecture degree from China, and a Master and Ph.D. in Engineering from Japan. Understanding geologic carbon sequestration Even with continued growth of renewable energy sources such as wind and solar, fossil fuels will likely remain cheap and plentiful for decades to come. Geologist Curt Oldenburg, who heads Berkeley Lab's Geologic Carbon Sequestration Program, will discuss a strategy to reduce carbon emissions from coal and natural gas. It involves pumping compressed CO2 captured from large stationary sources into underground rock formations that can store it for geological time scales.
Ramamoorthy Ramesh
Utilizing intake-air oxygen-enrichment technology to reduce cold- phase emissions
Oxygen-enriched combustion is a proven, serious considered technique to reduce exhaust hydrocarbons (HC) and carbon monoxide (CO) emissions from automotive gasoline engines. This paper presents the cold-phase emissions reduction results of using oxygen-enriched intake air containing about 23% and 25% oxygen (by volume) in a vehicle powered by a spark-ignition (SI) engine. Both engineout and converter-out emissions data were collected by following the standard federal test procedure (FTP). Converter-out emissions data were also obtained employing the US Environmental Protection Agency`s (EPA`s) ``Off-Cycle`` test. Test results indicate that the engine-out CO emissions during the cold phase (bag 1) were reduced by about 46 and 50%, and HC by about 33 and 43%, using nominal 23 and 25% oxygen-enriched air compared to ambient air (21% oxygen by volume), respectively. However, the corresponding oxides of nitrogen (NO{sub x}) emissions were increased by about 56 and 79%, respectively. Time-resolved emissions data indicate that both HC and CO emissions were reduced considerably during the initial 127 s of the cold-phase FTP, without any increase in NO, emissions in the first 25 s. Hydrocarbon speciation results indicate that all major toxic pollutants, including ozone-forming specific reactivity factors, such as maximum incremental reactivity (NUR) and maximum ozone incremental reactivity (MOIR), were reduced considerably with oxygen-enrichment. Based on these results, it seems that using oxygen-enriched intake air during the cold-phase FTP could potentially reduce HC and CO emissions sufficiently to meet future emissions standards. Off-cycle, converter-out, weighted-average emissions results show that both HC and CO emissions were reduced by about 60 to 75% with 23 or 25% oxygen-enrichment, but the accompanying NO{sub x}, emissions were much higher than those with the ambient air.
Poola, R.B.; Ng, H.K.; Sekar, R.R. [Argonne National Lab., IL (United States); Baudino, J.H. [Autoresearch Labs., Inc., Chicago, IL (United States); Colucci, C.P. [National Renewable Energy Lab., Golden, CO (United States)
Carbon velvet field-emission cathode
NASA Astrophysics Data System (ADS)
Explosive field emission cathodes comprise an important class of cathodes for high power microwave tubes, having the advantages of light weight as well as requiring no heater for electron emission. Generally, however, this class of cathodes suffers from large amounts of outgassing, nonuniform emission, and very high emittance. This article describes a new class of carbon velvet cathodes that have been coated with a cesium iodide (CsI) salt. We discuss two manifestations of the cathode. We review the lifetime and operation of the cathodes with two different pulse durations, as well as the outgassing from the cathodes during operation. Lifetimes in excess of 980 000 pulses have been obtained, with an outgassing rate of 3.5 atoms per electron. Finally, we discuss the uniformity and emittance of tufted carbon cathodes that have been coated with CsI salt. For comparison, we relate these results to those previously obtained from other cathodes in this class. The cathodes have an emittance of 2.5? mm rad, as compared to the theoretical value, based on computation, of 2.3? mm rad. These new cathodes differ greatly from cathodes such as polymer velvet and tufted carbon fiber cathodes in that no volatiles reside on the cathode and in that a unique coating technique allows the cathodes to function. This new class of cathodes offers a potential replacement for existing thermal cathodes, in that no heater is required for superior operation with low outgassing and long lifetime. Physics.
Shiffler, D.; Ruebush, M.; Haworth, M.; Umstattd, R.; Lacour, M.; Golby, K.; Zagar, D.; Knowles, T.
A Study on the Development of Low-carbon Economy in Shandong Province-Based on Empirical Analysis on the Influence Factor of Carbon Emission
The idea of low-carbon economy will focus on humanity's future. During the process of socio-economic development, if we want to reduce carbon emissions, we should optimize human production and improve the efficiency of energy. Based on the calculation of the carbon emission caused by energy consumption, this article used the correlation data from 1995 to 2008 in Shandong to analyze
ZHOU Rui; LI Shuang
Impact of Light-Duty Vehicle Emissions on 21st Century Carbon Dioxide Concentrations
The impact of light-duty passenger vehicle emissions on global carbon dioxide concentrations was estimated using the MAGICC reduced-form climate model combined with the PNNL contribution to the CCSP scenarios product. Our central estimate is that tailpipe light duty vehicle emissions of carbon-dioxide over the 21st century will increase global carbon dioxide concentrations by slightly over 12 ppmv by 2100.
Smith, Steven J.; Kyle, G. Page
Reduced carbon dots versus oxidized carbon dots: photo- and electrochemiluminescence investigations for selected applications.
The study of the composition, morphology, and surface structure of carbon dots (Cdots) is critical to understanding their effect on the photo- and electrochemiluminescence (PL and ECL) of Cdots in selected applications. Herein, two kinds of Cdots were prepared with 3-(3,4-dihydroxyphenyl)-L-alanine (L-DOPA) as precursor. The Cdots prepared by using a carbonization-extraction strategy have a low oxidation level and are denoted as reduced Cdots (r-Cdots). The Cdots obtained with a carbonization-oxidation process are highly oxidized and are denoted as oxidized Cdots (o-Cdots). The o-Cdots have a carbon core and oxygen-containing loose shell, but the r-Cdots consist mainly of the carbon core. Whereas r-Cdots have a strong blue PL but no apparent ECL response, o-Cdots exhibit a relatively weak PL and strong ECL emission. These properties allow for selected applications of the Cdots. The r-Cdots were used in cell imaging with their high PL emission. The o-Cdots, with their high ECL efficiencies, were selected to sense Cu(2+) with Cu(2+) -inducing ECL quenching in the o-Cdots/K2 S2 O8 system. This work provides the possibility to control the composition of Cdots for selected applications and shows a good way to characterize surface traps of Cdots because ECL is characterized by the surface-state and PL is mainly related to the core-state in Cdots. PMID:23526652
Xu, Yang; Wu, Ming; Feng, Xi-Zeng; Yin, Xue-Bo; He, Xi-Wen; Zhang, Yu-Kui
Nitrogen and phosphorous limitations significantly reduce future allowable CO2 emissions
NASA Astrophysics Data System (ADS)
Earth System Models (ESMs) can be used to diagnose the emissions of CO2 allowed in order to follow the representative concentration pathways (RCPs) that are consistent with different climate scenarios. By mass balance, the allowable emission is calculated as the sum of the changes in atmospheric CO2, land and ocean carbon pools. Only two ESMs used in the fifth assessment (AR5) of International Panel on Climate Change (IPCC) include nitrogen (N) limitation, and none include phosphorous (P) limitation. In this study we quantified the effects of N and P limitations on the allowable emissions using an ESM simulating land and ocean CO2 exchanges to the atmosphere in RCPs used for IPCC AR5. The model can run with carbon cycle alone (C only), carbon and nitrogen (CN) or carbon, nitrogen and phosphorus (CNP) cycles as its land configurations. We used the simulated land and ocean carbon accumulation rates from 1850 to 2100 to diagnose the allowable emissions for each of three simulations (C only, CN or CNP). These were then compared with the emissions estimated by the Integrated Assessment Models (IAMs) used to generate RCP2.6 and RCP8.5. N and P limitations on land in our ESM led to systematically lower land carbon uptake, and thus reduced allowable emissions by 69 Pg C (21%) for RCP2.6, and by 250 Pg C (13%) for RCP8.5 from 2006 to 2100. Our results demonstrated that including N and P limitations requires a greater reduction in human CO2 emissions than assumed in the IAMs used to generate the RCPs. Reference: Zhang, Q., Y. P. Wang, R. J. Matear, A. J. Pitman, and Y. J. Dai (2014), Nitrogen and phosphorous limitations significantly reduce future allowable CO2 emissions, Geophys. Res. Lett., 41, doi:10.1002/2013GL058352.
Zhang, Qian; Wang, Ying-Ping; Matear, Richard; Pitman, Andy; Dai, Yongjiu
The 11 Micron Emissions of Carbon Stars
NASA Technical Reports Server (NTRS)
A new classification scheme of the IRAS LRS carbon stars is presented. It comprises the separation of 718 probable carbon stars into 12 distinct self-similar spectral groupings. Continuum temperatures are assigned and range from 470 to 5000 K. Three distinct dust species are identifiable: SiC, alpha:C-H, and MgS. In addition to the narrow 11 + micron emission feature that is commonly attributed to SiC, a broad 11 + micron emission feature, that is correlated with the 8.5 and 7.7 micron features, is found and attributed to alpha:C-H. SiC and alpha:C-H band strengths are found to correlate with the temperature progression among the Classes. We find a spectral sequence of Classes that reflects the carbon star evolutionary sequence of spectral types, or alternatively developmental sequences of grain condensation in carbon-rich circumstellar shells. If decreasing temperature corresponds to increasing evolution, then decreasing temperature corresponds to increasing C/O resulting in increasing amounts of carbon rich dust, namely alpha:C-H. If decreasing the temperature corresponds to a grain condensation sequence, then heterogeneous, or induced nucleation scenarios are supported. SiC grains precede alpha:C-H and form the nuclei for the condensation of the latter material. At still lower temperatures, MgS appears to be quite prevalent. No 11.3 micron PAH features are identified in any of the 718 carbon stars. However, one of the coldest objects, IRAS 15048-5702, and a few others, displays an 11.9 micron emission feature characteristic of laboratory samples of coronene. That feature corresponds to the C-H out of plane deformation mode of aromatic hydrocarbon. This band indicates the presence of unsaturated, sp(sup 3), hydrocarbon bonds that may subsequently evolve into saturated bonds, sp(sup 2), if, and when, the star enters the planetary nebulae phase of stellar evolution. The effusion of hydrogen from the hydrocarbon grain results in the evolution in wavelength of this 11.9 micron emission feature to the 11.3 micron feature.
Goebel, J. H.; Cheeseman, P.; Gerbault, F.
This report defines the concept of parking management and explores how parking management can be used to improve air quality, support mass transit, reduce energy consumption and improve the amenities of life in urban areas. Specific aspects of this analysis were developments of a...
U.S. Energy-Related Carbon Dioxide Emissions
U.S. Energy Information Administration releases its online analysis of 2012 energy-related carbon dioxide emissions today. It indicates U.S. carbon dioxide emissions from the consumption of fossil fuels were 5,290 million metric tons carbon dioxide in 2012, a decrease of almost 4% from the 2011 level. Energy-related carbon dioxide emissions have declined in five of the last seven years and are the lowest they have been since 1994.
Elements for the expected mechanisms on 'reduced emissions from deforestation and degradation, REDD' under UNFCCC
NASA Astrophysics Data System (ADS)
Carbon emissions from deforestation and degradation account for about 20% of global anthropogenic emissions. Strategies and incentives for reduced emissions from deforestation and degradation (REDD) have emerged as one of the most active areas in the international climate change negotiations under the United Nations Framework Convention on Climate Change (UNFCCC). While the current negotiations focus on a REDD mechanism in developing countries, it should be recognized that risks of carbon losses from forests occur in all climate zones and also in industrialized countries. A future climate change agreement would be more effective if it included all carbon losses and gains from land use in all countries and climate zones. The REDD mechanism will be an important step towards reducing emissions from land use change in developing countries, but needs to be followed by steps in other land use systems and regions. A national approach to REDD and significant coverage globally are needed to deal with the risk that deforestation and degradation activities are displaced rather than avoided. Favourable institutional and governance conditions need to be established that guarantee in the long-term a stable incentive and control system for maintaining forest carbon stocks. Ambitious emission reductions from deforestation and forest degradation need sustained financial incentives, which go beyond positive incentives for reduced emissions but also give incentives for sustainable forest management. Current data limitations needŚand can beŚovercome in the coming years to allow accurate accounting of reduced emissions from deforestation and degradation. A proper application of the conservativeness approach in the REDD context could allow a simplified reporting of emissions from deforestation in a first phase, consistent with the already agreed UNFCCC reporting principles.
Mollicone, D.; Freibauer, A.; Schulze, E. D.; Braatz, S.; Grassi, G.; Federici, S.
Apparatus for reducing solvent luminescence background emissions
The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region.
Affleck, Rhett L. (Los Alamos, NM); Ambrose, W. Patrick (Los Alamos, NM); Demas, James N. (Charlottesville, VA); Goodwin, Peter M. (Jemez Springs, NM); Johnson, Mitchell E. (Pittsburgh, PA); Keller, Richard A. (Los Alamos, NM); Petty, Jeffrey T. (Los Alamos, NM); Schecker, Jay A. (Sante Fe, NM); Wu, Ming (Los Alamos, NM)
Apparatus for reducing solvent luminescence background emissions
The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region. 6 figs.
Affleck, R.L.; Ambrose, W.P.; Demas, J.N.; Goodwin, P.M.; Johnson, M.E.; Keller, R.A.; Petty, J.T.; Schecker, J.A.; Wu, M.
Incentives for reducing emissions in Krakow
This effort is identifying, specific incentives that may be used by Krakow city officials to encourage, residents to change the way they heat their homes and businesses in order to reduce pollution. This paper describes the incentives study for converting small coal or coke-fired boilers to gas in the Old Town area. A similar study looked at incentives for expanding the district heating system and future analyses will be performed for home stove options.
Uberman, R. [Polinvest Ltd., Krakow (Poland); Pierce, B. [Brookhaven National Lab., Upton, NY (United States); Lazecki, A. [Biuro Rozwoju Krakowa, Krakow (Poland)
Deterministic Cold Cathode Electron Emission from Carbon Nanofibre Arrays
NASA Astrophysics Data System (ADS)
The ability to accurately design carbon nanofibre (CN) field emitters with predictable electron emission characteristics will enable their use as electron sources in various applications such as microwave amplifiers, electron microscopy, parallel beam electron lithography and advanced Xray sources. Here, highly uniform CN arrays of controlled diameter, pitch and length were fabricated using plasma enhanced chemical vapour deposition and their individual emission characteristics and field enhancement factors were probed using scanning anode field emission mapping. For a pitch of 10 Ám and a CN length of 5 Ám, the directly measured enhancement factors of individual CNs was 242, which was in excellent agreement with conventional geometry estimates (240). We show here direct empirical evidence that in regular arrays of vertically aligned CNs the overall enhancement factor is reduced when the pitch between emitters is less than half the emitter height, in accordance to our electrostatic simulations. Individual emitters showed narrow Gaussian-like field enhancement distributions, in excellent agreement with electric field simulations.
Cole, Matthew T.; Teo, Kenneth B. K.; Groening, Oliver; Gangloff, Laurent; Legagneux, Pierre; Milne, William I.
Deterministic Cold Cathode Electron Emission from Carbon Nanofibre Arrays
The ability to accurately design carbon nanofibre (CN) field emitters with predictable electron emission characteristics will enable their use as electron sources in various applications such as microwave amplifiers, electron microscopy, parallel beam electron lithography and advanced Xray sources. Here, highly uniform CN arrays of controlled diameter, pitch and length were fabricated using plasma enhanced chemical vapour deposition and their individual emission characteristics and field enhancement factors were probed using scanning anode field emission mapping. For a pitch of 10?Ám and a CN length of 5?Ám, the directly measured enhancement factors of individual CNs was 242, which was in excellent agreement with conventional geometry estimates (240). We show here direct empirical evidence that in regular arrays of vertically aligned CNs the overall enhancement factor is reduced when the pitch between emitters is less than half the emitter height, in accordance to our electrostatic simulations. Individual emitters showed narrow Gaussian-like field enhancement distributions, in excellent agreement with electric field simulations.
Cole, Matthew T.; Teo, Kenneth B. K.; Groening, Oliver; Gangloff, Laurent; Legagneux, Pierre; Milne, William I.
Stability of Reduced Carbon in the Mantle
NASA Astrophysics Data System (ADS)
Reduced carbon in the mantle is commonly thought to be chiefly in diamond, but experiments suggest that at >250 km the mantle contains small amounts (0.1-1 %) of FeNi alloy [1, 2, 3]. Thus, alloy may be a significant host of reduced C [4], but little is known about C solubility of FeNi alloy under mantle conditions. To determine the carbon solubility in FeNi alloy and melt, we conducted experiments in the system Fe-Ni-C with bulk compositions having 5 wt. % C and variable Fe/(Fe+Ni) at 3 to 7 GPa and 1000--1400░C. Experiments at 3 GPa and 1000--1250 ░C were performed in an end loaded piston cylinder apparatus; those at 5 and 7 GPa and 1200--1400░C were performed in a 1000 ton Walker-style octahedral multianvil. At 3 GPa, Fe-rich melts contain up to 4.5 wt. % C, but Ni-rich (>25 mole% Ni) compositions remain subsolidus at 1250░C. The solubility of carbon in pure Fe and Ni metal are 2 wt. % and 1 wt. % respectively, but in the alloy passes through a minimum of 0.4 wt. % for Fe0.2Ni0.8. Assuming that these concentrations apply at higher temperatures and pressures (as will be tested by future experiments) allows a first estimate of the potential storage of C in FeNi alloy in the mantle. If the mantle at 250 km contains 0.1-0.2 wt.% Ni-rich (Fe0.4Ni0.6) alloy, increasing with depth to 1 wt.% Fe-rich (Fe0.88Ni0.12) alloy at 700 km [1,2], then maximum storage of C in alloy rises from 5 ppm in the deep upper mantle to 180 ppm in the shallow lower mantle. For mantle similar to the MORB source, with ~10-30 ppm C [5], alloy cannot store all C in the deep upper mantle but can in the lower mantle. For OIB sources with 33-500 ppm C [5], complete storage in alloy is less likely. Additional phases will be diamond in the upper mantle, as our experiments and previous work [6] indicate that carbide is not stable in equilibrium with Ni-rich alloy, and carbide melt in the lower mantle. [1] Frost et al (2004) Nature 428 409-412. [2] Frost and McCammon (2008) EPSL 36 389-420. [3] Rohrbach et al. (2011) J.Petrol 52 #717-731. [4] Dasgupta et al. (2009) GCA 73 6678-6691. [5] Dasgupta and Hirschmann (2010) EPSL 298 1-13. [6] Romig and Goldstein (1978) Metal Trans. Met. AIME 9a 1599-1609.
Hastings, Patrick Timothy, Jr.
The report was prepared to assist personnel responsible for the design, construction, and maintenance of retail food refrigeration equipment in making knowledgeable decisions regarding the implementation of refrigerant-emissions-reducing practices and technologies. It characteriz...
Wind farms on peatland: Effect of Management Practices on Carbon Emissions
NASA Astrophysics Data System (ADS)
The Scottish Government has set ambitious targets for electricity generation by renewables (Scottish Government, 2007). To meet the interim target of 31% electricity generation from renewable sources by 2011 and 50% by 2020, a substantial increase in the number of onshore wind farms is likely to be required. In Scotland a large number of proposed wind farm developments are on peatlands. One concern raised over the development of wind farms on peatlands questions whether the expected saving in carbon emissions due to electricity generation using wind power will be offset by increased carbon losses associated with the development. If carbon payback time exceeds the life time of the wind farm, then the development represents a net carbon cost. However, our calculations show that even on peatlands, good management practices can be used to minimise carbon losses and achieve carbon payback times that are significantly less than the lifetime of the wind farm. Using floating roads instead of excavated roads can minimise the carbon loss. Restoration of the site could potentially halt carbon loss processes, so allowing carbon dioxide emissions to be limited to the time before the habitat and hydrological conditions are restored. If the site is restored after decommissioning, the carbon payback time can be reduced by 50%. Habitat improvement at disturbed sites can significantly reduce carbon emissions, potentially preventing further losses and increasing carbon stored in the improved habitat. We present the calculations of carbon losses at a range of wind farm developments across Scotland, differing in soil type, climate, management practices and site design. We assess the impact of management and design on carbon emissions, and demonstrate the importance of good site management and design to reducing carbon emissions, especially for wind farms sited on peatlands.
Smith, J. U.; Nayak, D. R.; Miller, D.; Nolan, A.; Smith, P.
Provincial variation of carbon emissions from bituminous coal: Influence of inertinite and other factors
We observe a 1.3 kg C/net GJ variation of carbon emissions due to inertinite abundance in some commercially available bituminous coal. An additional 0.9 kg C/net GJ variation of carbon emissions is expected due to the extent of coalification through the bituminous rank stages. Each percentage of sulfur in bituminous coal reduces carbon emissions by about 0.08 kg C/net GJ. Other factors, such as mineral content, liptinite abundance and individual macerals, also influence carbon emissions, but their quantitative effect is less certain. The large range of carbon emissions within the bituminous rank class suggests that rank- specific carbon emission factors are provincial rather than global. Although carbon emission factors that better account for this provincial variation might be calculated, we show that the data used for this calculation may vary according to the methods used to sample and analyze coal. Provincial variation of carbon emissions and the use of different coal sampling and analytical methods complicate the verification of national greenhouse gas inventories. Published by Elsevier Science B.V.
Quick, J. C.; Brill, T.
Biomass and China's carbon emissions: A missing piece of carbon decomposition
A number of previous studies on China's carbon emissions have mainly focused on two facts: (1) the continuous growth in emissions up till the middle of the 1990s; (2) the recent stability of emissions from 1996 to 2001. Decomposition analysis has been widely used to explore the driving forces behind these phenomena. However, since 2002, China's carbon emissions have resumed
Chunbo Ma; David I. Stern
Reducing CO 2 emissions by substituting biomass for fossil fuels
Replacing fossil fuels with sustainably-produced biomass will reduce the net flow of CO2 to the atmosphere. We express the efficiency of this substitution in reduced emissions per unit of used land or biomass and in costs of the substitution per tonne of C. The substitution costs are calculated as the cost difference between continued use of fossil fuels at current
Leif Gustavsson; Pňl B÷rjesson; Bengt Johansson; Per Svenningsson
Estimates of increased black carbon emissions from electrostatic precipitators during powdered activated carbon injection for mercury emissions control.
The behavior of mercury sorbents within electrostatic precipitators (ESPs) is not well-understood, despite a decade or more of full-scale testing. Recent laboratory results suggest that powdered activated carbon exhibits somewhat different collection behavior than fly ash in an ESP and particulate filters located at the outlet of ESPs have shown evidence of powdered activated carbon penetration during full-scale tests of sorbent injection for mercury emissions control. The present analysis considers a range of assumed differential ESP collection efficiencies for powdered activated carbon as compared to fly ash. Estimated emission rates of submicrometer powdered activated carbon are compared to estimated emission rates of particulate carbon on submicrometer fly ash, each corresponding to its respective collection efficiency. To the extent that any emitted powdered activated carbon exhibits size and optical characteristics similar to black carbon, such emissions could effectively constitute an increase in black carbon emissions from coal-based stationary power generation. The results reveal that even for the low injection rates associated with chemically impregnated carbons, submicrometer particulate carbon emissions can easily double if the submicrometer fraction of the native fly ash has a low carbon content. Increasing sorbent injection rates, larger collection efficiency differentials as compared to fly ash, and decreasing sorbent particle size all lead to increases in the estimated submicrometer particulate carbon emissions. PMID:22663136
Clack, Herek L
A synthesis of carbon dioxide emissions from fossil-fuel combustion
This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores 5 our knowledge of these emissions in terms of why there is concern about them; how they are calculated; the major global efforts on inventorying them; their global, regional, and national totals at different spatial and temporal scales; how they are distributed on global grids (i.e. maps); how they are transported in models; and the uncertainties associated with these different aspects of the emissions. The magnitude of emissions 10 from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossil-fuel carbon dioxide emissions are known to within 10% uncertainty (95% 15 confidence interval). Uncertainty on individual national total fossil-fuel carbon dioxide emissions range from a few percent to more than 50 %. The information discussed in this manuscript synthesizes global, regional and national fossil-fuel carbon dioxide emissions, their distributions, their transport, and the associated uncertainties.
Andres, Robert Joseph [ORNL; Boden, Thomas A [ORNL; Breon, F.-M. [CEA/DSM/LSCE, Gif sur Yvette, France; Ciais, P. [LSCE/CEA, Gif-sur-Yvette, France; Davis, S. [Carnegie Institution of Washington; Erickson, D [Oak Ridge National Laboratory (ORNL); Gregg, J. S. [Riso National Laboratory, Roskilde, Denmark; Jacobson, Andrew [NOAA ESRL and CIRES; Marland, Gregg [Appalachian State University; Miller, J. [NOAA ESRL and CIRES; Oda, T [NOAA ESRL/Boulder, CO/Cooperative Institute for Research in the Atmosphere, Colorado State Univ.; Oliver, J. G. J. [PBL Netherlands Environmental Assessment Agency, Bilthoven, The Netherlands; Raupach, Michael [CSIRO Marine and Atmospheric Research; Rayner, P [University of Melbourne, Australia; Treanton, K. [Energy Statistics Division, International Energy Agency, Paris, France
Urban energy consumption and related carbon emission estimation: a study at the sector scale
NASA Astrophysics Data System (ADS)
With rapid economic development and energy consumption growth, China has become the largest energy consumer in the world. Impelled by extensive international concern, there is an urgent need to analyze the characteristics of energy consumption and related carbon emission, with the objective of saving energy, reducing carbon emission, and lessening environmental impact. Focusing on urban ecosystems, the biggest energy consumer, a method for estimating energy consumption and related carbon emission was established at the urban sector scale in this paper. Based on data for 1996-2010, the proposed method was applied to Beijing in a case study to analyze the consumption of different energy resources (i.e., coal, oil, gas, and electricity) and related carbon emission in different sectors (i.e., agriculture, industry, construction, transportation, household, and service sectors). The results showed that coal and oil contributed most to energy consumption and carbon emission among different energy resources during the study period, while the industrial sector consumed the most energy and emitted the most carbon among different sectors. Suggestions were put forward for energy conservation and emission reduction in Beijing. The analysis of energy consumption and related carbon emission at the sector scale is helpful for practical energy saving and emission reduction in urban ecosystems.
Lu, Weiwei; Chen, Chen; Su, Meirong; Chen, Bin; Cai, Yanpeng; Xing, Tao
Path dependence of climate and carbon cycle response over a broad range of cumulative carbon emissions
NASA Astrophysics Data System (ADS)
Recent studies have demonstrated the proportional relationship between global warming and cumulative carbon emissions, yet the robustness of this relationship has not been tested over a broad range of cumulative emissions and emission rates. This study explores the path dependence of the climate and carbon cycle response using an Earth System model of intermediate complexity forced with 24 idealized emissions scenarios across five cumulative emission groups (1275-5275 GtC) with varying rates of emission. We find the century-scale climate and carbon cycle response after cessation of emissions to be approximately independent of emission pathway for all cumulative emission levels considered. The ratio of global mean temperature change to cumulative emissions - referred to as the transient climate response to cumulative emissions (TCRE) - is found to be constant for cumulative emissions lower than ~1500 GtC, but to decline with higher cumulative emissions. The TCRE is also found to decrease with increasing emission rate. The response of Arctic sea ice is found to be approximately proportional to cumulative emissions, while the response of the Atlantic meridional overturning circulation (AMOC) does not scale linearly with cumulative emissions, as its peak response is strongly dependent on emission rate. Ocean carbon uptake weakens with increasing cumulative emissions, while land carbon uptake displays non-monotonic behavior, increasing up to a cumulative emission threshold of ~2000 GtC and then declining.
Herrington, T.; Zickfeld, K.
Reducing CO2 emissions and energy consumption of heat-integrated distillation systems.
Distillation systems are energy and power intensive processes and contribute significantly to the greenhouse gases emissions (e.g. carbon dioxide). Reducing CO2 emissions is an absolute necessity and expensive challenge to the chemical process industries in orderto meetthe environmental targets as agreed in the Kyoto Protocol. A simple model for the calculation of CO2 emissions from heat-integrated distillation systems is introduced, considering typical process industry utility devices such as boilers, furnaces, and turbines. Furnaces and turbines consume large quantities of fuels to provide electricity and process heats. As a result, they produce considerable amounts of CO2 gas to the atmosphere. Boilers are necessary to supply steam for heating purposes; besides, they are also significant emissions contributors. The model is used in an optimization-based approach to optimize the process conditions of an existing crude oil atmospheric tower in order to reduce its CO2 emissions and energy demands. It is also applied to generate design options to reduce the emissions from a novel internally heat-integrated distillation column (HIDiC). A gas turbine can be integrated with these distillation systems for larger emissions reduction and further energy savings. Results show that existing crude oil installations can save up to 21% in energy and 22% in emissions, when the process conditions are optimized. Additionally, by integrating a gas turbine, the total emissions can be reduced further by 48%. Internal heat-integrated columns can be a good alternative to conventional heat pump and other energy intensive close boiling mixtures separations. Energy savings can reach up to 100% with respect to reboiler heat requirements. Emissions of these configurations are cut down by up to 83%, compared to conventional units, and by 36%, with respect to heat pump alternatives. Importantly, cost savings and more profit are gained in parallel to emissions minimization. PMID:16190250
Gadalla, Mamdouh A; Olujic, Zarko; Jansens, Peter J; Jobson, Megan; Smith, Robin
Development of air conditioning technologies to reduce CO2 emissions in the commercial sector
Background Architectural methods that take into account global environmental conservation generally concentrate on mitigating the heat load of buildings. Here, we evaluate the reduction of carbon dioxide (CO2) emissions that can be achieved by improving heating, ventilating, and air conditioning (HVAC) technologies. Results The Climate Change Research Hall (CCRH) of the National Institute for Environmental Studies (NIES) is used as a case study. CCRH was built in line with the "Green Government Buildings" program of the Government Buildings Department at the Ministry of Land, Infrastructure and Transport in Japan. We have assessed the technology used in this building, and found that there is a possibility to reduce energy consumption in the HVAC system by 30%. Conclusion Saving energy reduces CO2 emissions in the commercial sector, although emission factors depend on the country or region. Consequently, energy savings potential may serve as a criterion in selecting HVAC technologies with respect to emission reduction targets.
Yoshida, Yukiko
Warming caused by cumulative carbon emissions towards the trillionth tonne.
Global efforts to mitigate climate change are guided by projections of future temperatures. But the eventual equilibrium global mean temperature associated with a given stabilization level of atmospheric greenhouse gas concentrations remains uncertain, complicating the setting of stabilization targets to avoid potentially dangerous levels of global warming. Similar problems apply to the carbon cycle: observations currently provide only a weak constraint on the response to future emissions. Here we use ensemble simulations of simple climate-carbon-cycle models constrained by observations and projections from more comprehensive models to simulate the temperature response to a broad range of carbon dioxide emission pathways. We find that the peak warming caused by a given cumulative carbon dioxide emission is better constrained than the warming response to a stabilization scenario. Furthermore, the relationship between cumulative emissions and peak warming is remarkably insensitive to the emission pathway (timing of emissions or peak emission rate). Hence policy targets based on limiting cumulative emissions of carbon dioxide are likely to be more robust to scientific uncertainty than emission-rate or concentration targets. Total anthropogenic emissions of one trillion tonnes of carbon (3.67 trillion tonnes of CO(2)), about half of which has already been emitted since industrialization began, results in a most likely peak carbon-dioxide-induced warming of 2 degrees C above pre-industrial temperatures, with a 5-95% confidence interval of 1.3-3.9 degrees C. PMID:19407800
Allen, Myles R; Frame, David J; Huntingford, Chris; Jones, Chris D; Lowe, Jason A; Meinshausen, Malte; Meinshausen, Nicolai
The challenges of reducing greenhouse gas emissions and air pollution through energy sources: evidence from a panel of developed countries.
The objective of the study is to investigate the long-run relationship between climatic factors (i.e., greenhouse gas emissions, agricultural methane emissions, and industrial nitrous oxide emission), air pollution (i.e., carbon dioxide emissions), and energy sources (i.e., nuclear energy; oil, gas, and coal energy; and fossil fuel energy) in the panel of 35 developed countries (including EU-15, new EU member states, G-7, and other countries) over a period of 1975-2012. In order to achieve this objective, the present study uses sophisticated panel econometric techniques including panel cointegration, panel fully modified OLS (FMOLS), and dynamic OLS (DOLS). The results show that there is a long-run relationship between the variables. Nuclear energy reduces greenhouse gases and carbon emissions; however, the other emissions, i.e., agricultural methane emissions and industrial nitrous oxide, are still to increase during the study period. Electricity production from oil, gas, and coal sources increases the greenhouse gases and carbon emissions; however, the intensity to increase emissions is far less than the intensity to increase emissions through fossil fuel. Policies that reduce emissions of greenhouse gases can simultaneously alter emissions of conventional pollutants that have deleterious effects on human health and the environment. PMID:24584642
Akhmat, Ghulam; Zaman, Khalid; Shukui, Tan; Sajjad, Faiza; Khan, Muhammad Azhar; Khan, Muhammad Zahir
Estimating the marginal cost of reducing global fossil fuel CO[sub 2] emissions
This paper estimates the marginal, total, and average cost and effectiveness of carbon taxes applied either by the Organization for Economic Cooperation and Development (OECD) members alone, or as part of a global cooperative strategy, to reduce potential future emissions and their direct implications for employment in the US coal industry. Two sets of cases are examined, one set in which OECD members acts alone, and another set in which the world acts in concert. In each case set taxes are examined which achieve four alternative levels of emissions reduction: halve the rate of emissions growth, no emissions growth, 20[percent] reduction from 1988 levels, and 50[percent] reduction from 1988 levels. For the global cooperation case, carbon tax rates of [dollar sign]32, [dollar sign]113, [dollar sign]161, and [dollar sign]517 per metric ton of carbon (mtC) were needed in the year 2025 to achieve the objectives. Total costs were respectively [dollar sign]40, [dollar sign]178, [dollar sign]253, and [dollar sign]848 billions of 1990 US dollars per year in the year 2025. Average costs were [dollar sign]32, [dollar sign]55, [dollar sign]59, and [dollar sign]135 per mtC. Costs were significantly higher in the cases in which the OECD members states acted alone. OECD member states, acting alone, could not reduce global emissions by 50[percent] or 20[percent] relative to 1988, given reference case assumptions regarding developing and recently planned nations economic growth.
Edmonds, J.; Barns, D.W.; McDonald, S. (Pacific Northwest Lab., Washington, DC (United States))
A reduced reaction model for carbon CVD\\/CVI processes
Carbonľcarbon composites are produced by chemical vapor deposition\\/chemical vapor infiltration (CVD\\/CVI) processes. Models of carbonľcarbon composite production processes will help reduce production costs. Reliable process models must, however, include details of the gas phase kinetics in order to identify optimal conditions. We have combined detailed gas phase kinetics, surface kinetics, and a pore closure model to predict pore geometry changes
Narayana Birakayala; Edward A Evans
Very stable electron field emission from strontium titanate coated carbon nanotube matrices with low emission thresholds.
Novel PMMA-STO-CNT matrices were created by opened-tip vertically aligned multiwalled carbon nanotubes (VA-MWCNTs) with conformal coatings of strontium titanate (STO) and poly(methyl methacrylate) (PMMA). Emission threshold of 0.8 V/?m was demonstrated, about 5-fold lower than that of the as-grown VA-MWCNTs. This was obtained after considering the related band structures under the perspective of work functions and tunneling width as a function of the STO thickness. We showed that there is an optimum thickness of STO coatings to effectively reduce the work function of CNTs and yet minimize the tunneling width for electron emissions. Furthermore, simulation and modeling suggest that PMMA-STO-CNT matrices have suppressed screening effects and Coulombs' repulsion forces between electrons in adjacent CNTs, leading to low emission threshold, high emission density, and prolonged emission stability. These findings are important for practical application of VA-MWCNTs in field emission devices, X-ray generation, and wave amplification. PMID:23199078
Pandey, Archana; Prasad, Abhishek; Moscatello, Jason P; Engelhard, Mark; Wang, Chongmin; Yap, Yoke Khin
The Logistics Equipment Carbon Emission Monitoring System for a Green Logistics
NASA Astrophysics Data System (ADS)
Recently, due to the global enforcement of obligations to reduce green house gases and various environmental regulations, low carbon green growth strategies are required. Currently, in our country, environment friendly logistics activities are staying in the early stage compared to advanced countries because of our country's large energy consumption type industrial structures. As a measure to respond to the trend of the reinforcement of international environmental regulations in the sector of logistics, active green logistics systems should be established and to solve this problem, this study is intended to develop a monitoring system that can manage the carbon emission of logistics equipment(container truck, discharging equipment etc) in real time using a new technology named IP-RFID. The monitoring system developed in this study can actively manage the carbon emission of individual logistics equipment by attaching IP-Tags that can measure the carbon emission of individual logistics equipment in real time and transmit the information obtained from the measurement directly to users through IP communication. Since carbon emission can be managed by logistics equipment and drivers can check the carbon emission of equipment through this system, the carbon emission generated in the logistics sector may be reduced by using this system.
Choi, Hyungrim; Park, Byoungkwon; Lee, Byungha; Park, Yongsung; Lee, Changsup; Ha, Jeongsoo
Reducing dust emissions at OAO Alchevskkoks coke battery 10A
Coke battery 10A with rammed batch is under construction at OAO Alchevskkoks. The design documentation developed by Giprokoks includes measures for reducing dust emissions to the atmosphere. Aspiration systems with dry dust trapping are employed in the new components of coke battery 10A and in the existing coke-sorting equipment. Two-stage purification of dusty air in cyclones and bag filters is employed for the coke-sorting equipment. This system considerably reduces coke-dust emissions to the atmosphere.
T.F. Trembach; E.N. Lanina [Giprokoks, the State Institute for the Design of Coke-Industry Enterprises, Kharkov (Ukraine)
Reducing Greenhouse Gas Emissions from Agricultural Wetlands in Borneo
NASA Astrophysics Data System (ADS)
At the forum G20 meeting in 2009, Indonesian President delivered Indonesia's commitment to reduce national greenhouse gas (GHG) emissions by 26% in 2020 by unilateral action and by 41% with support of other countries. To achieve the target, Indonesian government has put forestry, agriculture (including peatlands), energy, industry and transportation as main responsible sectors. Development of crop with low GHG emissions, increasing C sequestration and the use of organic fertilizers are among the activities to be carried out in 2010-2020 period to minimize GHG emissions from agricultural sectors. Three experiments have been carried out to elucidate the reflectivity of crop selection, soil ameliorants and organic fertilizers on GHG emissions from agricultural wetlands in Borneo. Firstly, gas samples were collected in weekly basis from oil palm, paddy, and vegetables fields and analyzed for methane (CH4) and nitrous oxide (N2O) concentrations by a gas chromatography. Secondly, coal fly ash, dolomite and ZnSO4 were incorporated into a pot containing peat and/or alluvial soils taken from wetlands in South Kalimantan. The air samples were taken and analyzed for CH4 by a gas chromatography. Finally, microbial consortium are isolated from soil, sediment and cow dung. The microbes were then propagated and used in a rice straw composting processes. The CO2, CH4 and N2O emissions from composting vessel were measured at one, two and four weeks of composting processes. The results showed that shifting the use of peatlands for oil palm to vegetable field reduced the GHG emissions by about 74% and that to paddy field reduce the GHG emissions by about 82%. The CH4 emissions from paddy field can be further reduced by applying dolomite. However, the use of coal fly ash and ZnSO4 increased CH4 emissions from peat soil cultivated to rice. The use of microbe isolated from saline soil could reduce GHG emissions during the composting of rice straw. The social aspect of GHG reduction in Borneo will also be discussed.
Abdul, H.; Fatah, L.; Nursyamsi, D.; Kazuyuki, I.
Using Carbon Emissions Data to "Heat Up" Descriptive Statistics
ERIC Educational Resources Information Center
This article illustrates using carbon emissions data in an introductory statistics assignment. The carbon emissions data has desirable characteristics including: choice of measure; skewness; and outliers. These complexities allow research and public policy debate to be introduced. (Contains 4 figures and 2 tables.)
Brooks, Robert
Energy use and carbon emissions: Non-OECD countries
This report surveys world energy use and carbon emissions patterns, with particular emphasis on the non-OECD countries. The non OECD is important not only because it currently makes up 84% of world population, but because its energy consumption, carbon emissions, population, and grow domestic product have all been growing faster than OECD`s. This presentation has seven major sections: (1) overview of key trends in non-OECD energy use and carbon emissions since 1970; (2) Comparison and contrasting energy use and carbon emissions for five major non OEDC regions (former Soviet Union and eastern Europe, Pacific Rim including China, Latin America, other Asia; Africa; 3-7) presentation of aggregate and sectoral energy use and carbon emissions data for countries within each of the 5 regions.
Not Available
Reducing transit bus emissions: Alternative fuels or traffic operations?
NASA Astrophysics Data System (ADS)
In this study, we simulated the operations and greenhouse gas (GHG) emissions of transit buses along a busy corridor and quantified the effects of two different fuels (conventional diesel and compressed natural gas) as well as a set of driving conditions on emissions. Results indicate that compressed natural gas (CNG) reduces GHG emissions by 8-12% compared to conventional diesel, this reduction could increase to 16% with high levels of traffic congestion. However, the benefits of switching from conventional diesel to CNG are less apparent when the road network is uncongested. We also investigated the effects of bus operations on emissions by applying several strategies such as transit signal priority (TSP), queue jumper lanes, and relocation of bus stops. Results show that in congested conditions, TSP alone can reduce GHG emissions by 14% and when combined with improved technology; a reduction of 23% is achieved. The reduction benefits are even more apparent when other transit operational improvements are combined with TSP. Finally a sensitivity analysis was performed to investigate the effect of operational improvements on emissions under varying levels of network congestion. We observe that under ôextreme congestionö, the benefits of TSP decrease.
Alam, Ahsan; Hatzopoulou, Marianne
An audit of the global carbon budget: identifying and reducing sources of uncertainty
NASA Astrophysics Data System (ADS)
Uncertainties in our carbon accounting practices may limit our ability to objectively verify emission reductions on regional scales. Furthermore uncertainties in the global C budget must be reduced to benchmark Earth System Models that incorporate carbon-climate interactions. Here we present an audit of the global C budget where we try to identify sources of uncertainty for major terms in the global C budget. The atmospheric growth rate of CO2 has increased significantly over the last 50 years, while the uncertainty in calculating the global atmospheric growth rate has been reduced from 0.4 ppm/yr to 0.2 ppm/yr (95% confidence). Although we have greatly reduced global CO2 growth rate uncertainties, there remain regions, such as the Southern Hemisphere, Tropics and Arctic, where changes in regional sources/sinks will remain difficult to detect without additional observations. Increases in fossil fuel (FF) emissions are the primary factor driving the increase in global CO2 growth rate; however, our confidence in FF emission estimates has actually gone down. Based on a comparison of multiple estimates, FF emissions have increased from 2.45 ▒ 0.12 PgC/yr in 1959 to 9.40 ▒ 0.66 PgC/yr in 2010. Major sources of increasing FF emission uncertainty are increased emissions from emerging economies, such as China and India, as well as subtle differences in accounting practices. Lastly, we evaluate emission estimates from Land Use Change (LUC). Although relative errors in emission estimates from LUC are quite high (2 sigma ~ 50%), LUC emissions have remained fairly constant in recent decades. We evaluate the three commonly used approaches to estimating LUC emissions- Bookkeeping, Satellite Imagery, and Model Simulations- to identify their main sources of error and their ability to detect net emissions from LUC.; Uncertainties in Fossil Fuel Emissions over the last 50 years.
Ballantyne, A. P.; Tans, P. P.; Marland, G.; Stocker, B. D.
Reducing Gaseous Emissions from Beef Cattle Feedlot Surfaces
A laboratory study was conducted to evaluate soil amendments for reducing ammonia emissions from open-lot beef cattle feedyards. A mixture of 1550 g of soil, 133 g of feces, and 267 g of urine was placed into sealed plastic containers of dimensions 20 cm x 20 cm x 12 cm depth. Using a vacuum system, clean air at a rate
D. B. Parker; N. A. Cole; Y. Shi; B. W. Auvermann; J. E. Mehlhorn; L. W. Greene
Transient Suppression Packaging for Reduced Emissions from Rotary Kiln Incinerators
Experiments were performed on a 73 kW rotary kiln incinerator simulator to determine whether innovative waste packaging designs might reduce transient emissions of products of incomplete combustion due to batch charging of containerized liquid surrogate waste compounds bound on ground corncob sorbent. When containers of waste are batch charged into rotary kilns, the rupture of the container is often followed
PAUL M. LEMIEUX; WILLIAM P. LINAK; JOSEPH A. McSORLEY; JOST O. L. WENDT
Experiments were performed on a 73 kW rotary kiln incinerator simulator to determine whether innovative waste packaging designs might reduce transient emissions of products of incomplete combustion due to batch charging of containerized liquid surrogate waste compounds bound on g...
Estimated Carbon Dioxide Emissions in 2008: United States
Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three
C A Smith; A J Simon; R D Belles
Potential of Miscanthus grasses to provide energy and hence reduce greenhouse gas emissions
Using bio-fuels, such as bio-ethanol or bio-diesel in transportation, or biomass in power generation reduces CO2 emissions as the carbon is fixed by the plants from the atmosphere and saves the equivalent fossil fuel. The perennial rhizomatous\\u000a C4 grass Miscanthus has one of the highest energy intensities per hectare of land in Europe. Here we model the future potential of
Astley Hastings; John Clifton-Brown; Martin Wattenbach; Paul Stampfl; C. Paul Mitchell; Pete Smith
Unsuccessful suicide by carbon monoxide: a secondary benefit of emissions control
Emission systems and devices are required on automobile engines to reduce air pollution problems. Catalytic converters have been used on most 1975 and newer automobiles to reduce hydrocarbon and carbon monoxide (CO) emissions to a value that meets the Environmental Protection Agency requirements established for 1975 and 1976. The 1980-1981 Boise, Idaho, study shows that with a functioning catalytic converter either unmeasurable or sublethal quantities of CO appear in automobile exhaust. Thus, emissions control has produced a secondary benefit in reducing the number of suicides by CO poisoning from automobile exhaust fumes.
Landers, D.
Field-emission studies of smooth and nanostructured carbon films
NASA Astrophysics Data System (ADS)
Electron field-emission measurements of carbon films prepared by pulsed-laser deposition (PLD) and hot-filament chemical-vapor deposition (HF-CVD) are reported. Smooth PLD carbon films, with both high- and low-sp3 contents, appear to be poor field emitters. In contrast, HF-CVD carbon exhibits very good field-emission properties, including the emission turn-on field as low as 9 V/?m, high emission site density, and excellent durability. In addition, HF-CVD was carried out at temperatures below 600 ░C, compatible with the use of glass substrates. The promising field-emission properties of HF-CVD carbon are attributed to the nanostructured nature of this material.
Merkulov, Vladimir I.; Lowndes, Douglas H.; Baylor, Larry R.
Transitions in pathways of human development and carbon emissions
NASA Astrophysics Data System (ADS)
Countries are known to follow diverse pathways of life expectancy and carbon emissions, but little is known about factors driving these dynamics. In this letter we estimate the cross-sectional economic, demographic and geographic drivers of consumption-based carbon emissions. Using clustering techniques, countries are grouped according to their drivers, and analysed with respect to a criteria of one tonne of carbon emissions per capita and a life expectancy over 70 years (Goldembergĺs Corner). Five clusters of countries are identified with distinct drivers and highly differentiated outcomes of life expectancy and carbon emissions. Representatives from four clusters intersect within Goldembergĺs Corner, suggesting diverse combinations of drivers may still lead to sustainable outcomes, presenting many countries with an opportunity to follow a pathway towards low-carbon human development. By contrast, within Goldembergĺs Corner, there are no countries from the core, wealthy consuming nations. These results reaffirm the need to address economic inequalities within international agreements for climate mitigation, but acknowledge plausible and accessible examples of low-carbon human development for countries that share similar underlying drivers of carbon emissions. In addition, we note differences in drivers between models of territorial and consumption-based carbon emissions, and discuss interesting exceptions to the drivers-based cluster analysis.
Lamb, W. F.; Steinberger, J. K.; Bows-Larkin, A.; Peters, G. P.; Roberts, J. T.; Wood, F. R.
New technologies reduce greenhouse gas emissions from nitrogenous fertilizer in China.
Synthetic nitrogen (N) fertilizer has played a key role in enhancing food production and keeping half of the world's population adequately fed. However, decades of N fertilizer overuse in many parts of the world have contributed to soil, water, and air pollution; reducing excessive N losses and emissions is a central environmental challenge in the 21st century. China's participation is essential to global efforts in reducing N-related greenhouse gas (GHG) emissions because China is the largest producer and consumer of fertilizer N. To evaluate the impact of China's use of N fertilizer, we quantify the carbon footprint of China's N fertilizer production and consumption chain using life cycle analysis. For every ton of N fertilizer manufactured and used, 13.5 tons of CO2-equivalent (eq) (t CO2-eq) is emitted, compared with 9.7 t CO2-eq in Europe. Emissions in China tripled from 1980 [131 terrogram (Tg) of CO2-eq (Tg CO2-eq)] to 2010 (452 Tg CO2-eq). N fertilizer-related emissions constitute about 7% of GHG emissions from the entire Chinese economy and exceed soil carbon gain resulting from N fertilizer use by several-fold. We identified potential emission reductions by comparing prevailing technologies and management practices in China with more advanced options worldwide. Mitigation opportunities include improving methane recovery during coal mining, enhancing energy efficiency in fertilizer manufacture, and minimizing N overuse in field-level crop production. We find that use of advanced technologies could cut N fertilizer-related emissions by 20-63%, amounting to 102-357 Tg CO2-eq annually. Such reduction would decrease China's total GHG emissions by 2-6%, which is significant on a global scale. PMID:23671096
Zhang, Wei-Feng; Dou, Zheng-Xia; He, Pan; Ju, Xiao-Tang; Powlson, David; Chadwick, Dave; Norse, David; Lu, Yue-Lai; Zhang, Ying; Wu, Liang; Chen, Xin-Ping; Cassman, Kenneth G; Zhang, Fu-Suo
Interactions between reducing CO2 emissions, CO2 removal and solar radiation management.
We use a simple carbon cycle-climate model to investigate the interactions between a selection of idealized scenarios of mitigated carbon dioxide emissions, carbon dioxide removal (CDR) and solar radiation management (SRM). Two CO(2) emissions trajectories differ by a 15-year delay in the start of mitigation activity. SRM is modelled as a reduction in incoming solar radiation that fully compensates the radiative forcing due to changes in atmospheric CO(2) concentration. Two CDR scenarios remove 300 PgC by afforestation (added to vegetation and soil) or 1000 PgC by bioenergy with carbon capture and storage (removed from system). Our results show that delaying the start of mitigation activity could be very costly in terms of the CDR activity needed later to limit atmospheric CO(2) concentration (and corresponding global warming) to a given level. Avoiding a 15-year delay in the start of mitigation activity is more effective at reducing atmospheric CO(2) concentrations than all but the maximum type of CDR interventions. The effects of applying SRM and CDR together are additive, and this shows most clearly for atmospheric CO(2) concentration. SRM causes a significant reduction in atmospheric CO(2) concentration due to increased carbon storage by the terrestrial biosphere, especially soils. However, SRM has to be maintained for many centuries to avoid rapid increases in temperature and corresponding increases in atmospheric CO(2) concentration due to loss of carbon from the land. PMID:22869802
Vaughan, Naomi E; Lenton, Timothy M
Appraisal of policy instruments for reducing buildings' CO2 emissions
The building sector currently contributes approximately one-third of energy-related CO2 emissions worldwide. It is economically possible to achieve a 30% reduction. However, numerous barriers such as financial and behavioural issues, market failures, and misplaced incentives prevent the realization of the high economic potentials. Which policy instruments are the most appropriate and cost-effective for reducing these barriers? To address this question,
Diana Řrge-Vorsatz; Sonja Koeppel; Sebastian Mirasgedis
Remote microwave technology for chamber clean to reduce PFC emissions
Applied Materials has developed a new chamber cleaning technology that has the potential to dramatically reduce PFC emissions from chamber cleaning on their DÎZTM platform. The prototype product, known as ?CleanTM, is a remote microwave clean using NF3 that can be retrofitted to a DÎZ chamber. Recent tests of ?Clean technology conducted by Air Products and Chemicals, Inc. at Applied
L. Mendicino; S. Filipiak; P. T. Brown; J. Langan; R. Ridgeway; A. Johnson; R. Pearce; P. Maroulis; A. Atherton
Deterministic cold cathode electron emission from carbon nanofibre arrays.
The ability to accurately design carbon nanofibre (CN) field emitters with predictable electron emission characteristics will enable their use as electron sources in various applications such as microwave amplifiers, electron microscopy, parallel beam electron lithography and advanced Xray sources. Here, highly uniform CN arrays of controlled diameter, pitch and length were fabricated using plasma enhanced chemical vapour deposition and their individual emission characteristics and field enhancement factors were probed using scanning anode field emission mapping. For a pitch of 10?Ám and a CN length of 5?Ám, the directly measured enhancement factors of individual CNs was 242, which was in excellent agreement with conventional geometry estimates (240). We show here direct empirical evidence that in regular arrays of vertically aligned CNs the overall enhancement factor is reduced when the pitch between emitters is less than half the emitter height, in accordance to our electrostatic simulations. Individual emitters showed narrow Gaussian-like field enhancement distributions, in excellent agreement with electric field simulations. PMID:24787895
Cole, Matthew T; Teo, Kenneth B K; Groening, Oliver; Gangloff, Laurent; Legagneux, Pierre; Milne, William I
Estimated Carbon Dioxide Emissions in 2008: United States
Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three major energy resources: natural gas, coal, and petroleum. The flow patterns are represented in a compact 'visual atlas' of 52 state-level (all 50 states, the District of Columbia, and one national) carbon dioxide flow charts representing a comprehensive systems view of national CO{sub 2} emissions. Lawrence Livermore National Lab (LLNL) has published flow charts (also referred to as 'Sankey Diagrams') of important national commodities since the early 1970s. The most widely recognized of these charts is the U.S. energy flow chart (http://flowcharts.llnl.gov). LLNL has also published charts depicting carbon (or carbon dioxide potential) flow and water flow at the national level as well as energy, carbon, and water flows at the international, state, municipal, and organizational (i.e. United States Air Force) level. Flow charts are valuable as single-page references that contain quantitative data about resource, commodity, and byproduct flows in a graphical form that also convey structural information about the system that manages those flows. Data on carbon dioxide emissions from the energy sector are reported on a national level. Because carbon dioxide emissions are not reported for individual states, the carbon dioxide emissions are estimated using published energy use information. Data on energy use is compiled by the U.S. Department of Energy's Energy Information Administration (U.S. EIA) in the State Energy Data System (SEDS). SEDS is updated annually and reports data from 2 years prior to the year of the update. SEDS contains data on primary resource consumption, electricity generation, and energy consumption within each economic sector. Flow charts of state-level energy usage and explanations of the calculations and assumptions utilized can be found at: http://flowcharts.llnl.gov. This information is translated into carbon dioxide emissions using ratios of carbon dioxide emissions to energy use calculated from national carbon dioxide emissions and national energy use quantities for each particular sector. These statistics are reported annually in the U.S. EIA's Annual Energy Review. Data for 2008 (US. EIA, 2010) was updated in August of 2010. This is the first presentation of a comprehensive state-level package of flow charts depicting carbon dioxide emissions for the United States.
Smith, C A; Simon, A J; Belles, R D
A Reduced Organic Carbon Component in Martian Basalts
NASA Astrophysics Data System (ADS)
The source and nature of carbon on Mars have been a subject of intense speculation. We report the results of confocal Raman imaging spectroscopy on 11 martian meteorites, spanning about 4.2 billion years of martian history. Ten of the meteorites contain abiotic macromolecular carbon (MMC) phases detected in association with small oxide grains included within high-temperature minerals. Polycyclic aromatic hydrocarbons were detected along with MMC phases in Dar al Gani 476. The association of organic carbon within magmatic minerals indicates that martian magmas favored precipitation of reduced carbon species during crystallization. The ubiquitous distribution of abiotic organic carbon in martian igneous rocks is important for understanding the martian carbon cycle and has implications for future missions to detect possible past martian life.
Steele, A.; McCubbin, F. M.; Fries, M.; Kater, L.; Boctor, N. Z.; Fogel, M. L.; Conrad, P. G.; Glamoclija, M.; Spencer, M.; Morrow, A. L.; Hammond, M. R.; Zare, R. N.; Vicenzi, E. P.; Siljestr÷m, S.; Bowden, R.; Herd, C. D. K.; Mysen, B. O.; Shirey, S. B.; Amundsen, H. E. F.; Treiman, A. H.; Bullock, E. S.; Jull, A. J. T.
Carbon fibers are highly conductive, lightweight and of small dimensions. When released as emissions from production, manufacturing, processing and disposal sources they may become airborne and disperse over wide areas. If they settle onto electronic or electrical components they...
Energy Use and Carbon Emissions: Non-OECD Countries
Presents world energy use and carbon emissions patterns, with particular emphasis on the non-OECD (Organization for Economic Cooperation and Development) countries (including the current and former centrally planned economies).
Information Center
Field emission cathodes based on milled carbon fibers
NASA Astrophysics Data System (ADS)
In this paper, the production technology of field emission cathodes based on ball-milled carbon fibers is presented. The method is to use carbon fiber powder with optimal particle size. For the powder deposition on the cathode base, a screen-printing technique has been applied. The cathode structure obtained can provide significant electric field enhancement. The field emission properties of these cathodes are reported.
Sheshin, E. P.; Baturin, A. S.; Nikolskiy, K. N.; Tchesov, R. G.; Sharov, V. B.
Derivation of burn scar depths and estimation of carbon emissions with LIDAR in Indonesian peatlands.
During the 1997/98 El Ni˝o-induced drought peatland fires in Indonesia may have released 13-40% of the mean annual global carbon emissions from fossil fuels. One major unknown in current peatland emission estimations is how much peat is combusted by fire. Using a light detection and ranging data set acquired in Central Kalimantan, Borneo, in 2007, one year after the severe peatland fires of 2006, we determined an average burn scar depth of 0.33 +/- 0.18 m. Based on this result and the burned area determined from satellite imagery, we estimate that within the 2.79 million hectare study area 49.15 +/- 26.81 megatons of carbon were released during the 2006 El Ni˝o episode. This represents 10-33% of all carbon emissions from transport for the European Community in the year 2006. These emissions, originating from a comparatively small area (approximately 13% of the Indonesian peatland area), underline the importance of peat fires in the context of green house gas emissions and global warming. In the past decade severe peat fires occurred during El Ni˝o-induced droughts in 1997, 2002, 2004, 2006, and 2009. Currently, this important source of carbon emissions is not included in IPCC carbon accounting or in regional and global carbon emission models. Precise spatial measurements of peat combusted and potential avoided emissions in tropical peat swamp forests will also be required for future emission trading schemes in the framework of Reduced Emissions from Deforestation and Degradation in developing countries. PMID:19940252
Ballhorn, Uwe; Siegert, Florian; Mason, Mike; Limin, Suwido
Derivation of burn scar depths and estimation of carbon emissions with LIDAR in Indonesian peatlands
During the 1997/98 El Ni˝o-induced drought peatland fires in Indonesia may have released 13ľ40% of the mean annual global carbon emissions from fossil fuels. One major unknown in current peatland emission estimations is how much peat is combusted by fire. Using a light detection and ranging data set acquired in Central Kalimantan, Borneo, in 2007, one year after the severe peatland fires of 2006, we determined an average burn scar depth of 0.33 ▒ 0.18 m. Based on this result and the burned area determined from satellite imagery, we estimate that within the 2.79 million hectare study area 49.15 ▒ 26.81 megatons of carbon were released during the 2006 El Ni˝o episode. This represents 10ľ33% of all carbon emissions from transport for the European Community in the year 2006. These emissions, originating from a comparatively small area (approximately 13% of the Indonesian peatland area), underline the importance of peat fires in the context of green house gas emissions and global warming. In the past decade severe peat fires occurred during El Ni˝o-induced droughts in 1997, 2002, 2004, 2006, and 2009. Currently, this important source of carbon emissions is not included in IPCC carbon accounting or in regional and global carbon emission models. Precise spatial measurements of peat combusted and potential avoided emissions in tropical peat swamp forests will also be required for future emission trading schemes in the framework of Reduced Emissions from Deforestation and Degradation in developing countries.
Ballhorn, Uwe; Siegert, Florian; Mason, Mike; Limin, Suwido
A model of plant isoprene emission based on available reducing power captures responses to atmospheric CO?.
We present a unifying model for isoprene emission by photosynthesizing leaves based on the hypothesis that isoprene biosynthesis depends on a balance between the supply of photosynthetic reducing power and the demands of carbon fixation. We compared the predictions from our model, as well as from two other widely used models, with measurements of isoprene emission from leaves of Populus nigra and hybrid aspen (Populus tremula Î P. tremuloides) in response to changes in leaf internal CO2 concentration (C(i)) and photosynthetic photon flux density (PPFD) under diverse ambient CO2 concentrations (C(a)). Our model reproduces the observed changes in isoprene emissions with C(i) and PPFD, and also reproduces the tendency for the fraction of fixed carbon allocated to isoprene to increase with increasing PPFD. It also provides a simple mechanism for the previously unexplained decrease in the quantum efficiency of isoprene emission with increasing C(a). Experimental and modelled results support our hypothesis. Our model can reproduce the key features of the observations and has the potential to improve process-based modelling of isoprene emissions by land vegetation at the ecosystem and global scales. PMID:24661143
Morfopoulos, Catherine; Sperlich, Dominik; Pe˝uelas, Josep; Filella, Iolanda; LlusiÓ, Joan; Medlyn, Belinda E; Niinemets, ▄lo; Possell, Malcolm; Sun, Zhihong; Prentice, Iain Colin
Hedging Carbon Risk: Protecting Customers and Shareholders from the Financial Risk Associated with Carbon Dioxide Emissions
Utilities and regulators are recognizing the imprudence of assuming that carbon dioxide emissions will not cost anything over the long lifetime of new investments. Several utilities have begun to protect their customers and shareholders from this financial risk by integrating an estimated cost of carbon dioxide emissions into their evaluation of resource options, and selecting the overall least-cost portfolio of resources.
Bokenkamp, Karl; LaFlash, Hal; Singh, Virinder; Bachrach Wang, Devra
Effect of Purity and Substrate on Field Emission Properties of Multi-walled Carbon Nanotubes.
Multi-walled carbon nanotubes (MWNT) have been synthesized by chemical vapour decomposition (CVD) of acetylene over Rare Earth (RE) based AB2(DyNi2) alloy hydride catalyst. The as-grown carbon nanotubes were purified by acid and heat treatments and characterized using powder X-ray diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy, Thermo Gravimetric Analysis and Raman Spectroscopy. Fully carbon based field emitters have been fabricated by spin coating a solutions of both as-grown and purified MWNT and dichloro ethane (DCE) over carbon paper with and without graphitized layer. The use of graphitized carbon paper as substrate opens several new possibilities for carbon nanotube (CNT) field emitters, as the presence of the graphitic layer provides strong adhesion between the nanotubes and carbon paper and reduces contact resistance. The field emission characteristics have been studied using an indigenously fabricated set up and the results are discussed. CNT field emitter prepared by spin coating of the purified MWNT-DCE solution over graphitized carbon paper shows excellent emission properties with a fairly stable emission current over a period of 4 h. Analysis of the field emission characteristics based on the Fowler-Nordheim (FN) theory reveals current saturation effects at high applied fields for all the samples. PMID:21798103
Rakhi, Rb; Sethupathi, K; Ramaprabhu, S
Modification of carbon-fiber-composite surface emissivity/reflectance by high-index interference films
NASA Astrophysics Data System (ADS)
High strength/weight carbon fiber-reinforced composites (CFRCs) are finding applications where control of surface infrared emission or reflection is desirable. A quarter wave sputtered Ge film has been shown to reduce the normal emittance of a bismaleimide CFRC in the 8 - 14 micrometers band by 39%, with angle dependence theoretically constant out to 80% off-axis. A three-layer HLH stack is predicted to reduce emittance of less than 0.1. For thermal IR polymer curing, a single-layer coating optimizing emissivity in the polymer's absorption band while suppressing emission at longer wavelengths may yield electric power savings in the 10 - 20% range.
Pike, John N.; Matthews, Linn H.
Short and Long Term Impacts of Forest Bioenergy Production on Atmospheric Carbon Dioxide Emissions
NASA Astrophysics Data System (ADS)
Temperate forest annual net uptake of CO2 from the atmosphere is equivalent to ~16% of the annual fossil fuel emissions in the United States. Mitigation strategies to reduce emissions of carbon dioxide have lead to investigation of alternative sources of energy including forest biomass. The prospect of forest derived bioenergy has led to implementation of new forest management strategies based on the assumption that they will reduce total CO2 emissions to the atmosphere by simultaneously reducing the risk of wildfire and substituting for fossil fuels. The benefit of managing forests for bioenergy substitution of fossil fuels versus potential carbon sequestration by reducing harvest needs to be evaluated. This study uses a combination of Federal Forest Inventory data (FIA), remote sensing, and a coupled carbon-nitrogen ecosystem process model (CLM4-CN) to predict net atmospheric CO2 emissions from forest thinning for bioenergy production in Oregon under varying future management and climate scenarios. We use life-cycle assessment (LCA) incorporating both the forest and forest product sinks and sources of carbon dioxide. Future modeled results are compared with a reduced harvest scenario to determine the potential for increased carbon sequestration in forest biomass. We find that Oregon forests are a current strong sink of 7.5 ▒ 1.7 Tg C yr-1 or 61 g C m-2 yr-1. (NBP; NEP minus removals from fire and harvest). In the short term, we find that carbon dynamics following harvests for fire prevention and large-scale bioenergy production lead to 2-15% higher emissions over the next 20 years compared to current management, assuming 100% effectiveness of fire prevention. Given the current sink strength, analysis of the forest sector in Oregon demonstrates that increasing harvest levels by all practices above current business-as-usual levels increases CO2 emissions to the atmosphere as long as the region's sink persists. In the long-term, we find that projected changes in climate and fire regimes reduce the baseline sink in drier portions of the state making thinning for bioenergy production an effective means to reduce atmospheric emissions. However, in the more productive wetter areas, management for carbon sequestration removes more CO2 from the atmosphere than substitution of fossil fuels with forest bioenergy. Management strategies should consider the emission reduction potential of reducing harvest in some areas before implementing bioenergy production.
Hudiburg, T.; Law, B. E.; Luyssaert, S.; Thornton, P. E.
Wildfire carbon emission dependence on precipitation and temperature cyclic variation over Africa
NASA Astrophysics Data System (ADS)
In semi-arid regions of Africa, wildfire frequently occurs during dry season. The wildfires strongly constrain the structure, dynamics, and distribution of vegetation, and emit the large amount of carbonaceous aerosol. The atmospheric carbonaceous aerosol has ability to change climatic system, because it absorbs or reflects shortwave radiation. Carbon emissions of wildfire are sensitive to fluctuation in precipitation and temperature which affects vegetation productivity and have been successfully related to the large scale phenomena such as the El Nino Southern Oscillation and the Indian Ocean Dipole Oscillation. However, change of carbon emissions with respect to cyclic variability in precipitation and temperature has yet to be adequately evaluated quantitatively. Our purpose is to estimate the ratio of change of carbon emissions with respect to cyclic variability in annual mean temperature and annual precipitation for about two decade over Africa. In this study, we estimate the carbon emissions from wildfire using SEIB-DGVM (Spacialy Explicit Individual Base Dynamic Global Vegetation Model). The study area is African continent (37░N-34░S, 17░W-59░S). The following three experiments were conducted. First, verification experiment: the simulation was conducted for 13 years from 1997 to 2009. Second, no cyclic climate experiment: a created climate data which close to the average of annual mean temperature or annual precipitation from 1982 to 2009 were used for this experiment. Third, cyclic climate change experiment: the precipitation and temperature data, which changes periodically with 6, 10, and 20-year cycle based on the standard deviation, were used as the input climate data set. The verification experiment: the estimated annual carbon emissions of wildfire give good agreement with satellite observation, but simulation was overestimated for the integrated annual carbon emissions in each northern and southern hemisphere. The no cyclic climate change experiment: the carbon emission in the northern hemisphere was decreased, while it did not change in the southern hemisphere. A tree coverage and biomass were increased because tree mortality due to extreme drought was eliminated. Because the probability of fire occurrence was reduced by increase high tree coverage region, carbon emission in the northern hemisphere was decreased. The cyclic in climate change experiment: the carbon emission in the northern and southern hemisphere was increased because increase of low tree coverage region caused relatively high probability of fire occurrence. The change of carbon emission with respect to cyclic variability of annual precipitation was greater than that of temperature. Current carbon emissions of wildfire are affected by change in period of annual precipitation, and very sensitive to change in tree coverage that controls to probability of fire occurrence.
Ishii, S.; SATO, H.; Yamazaki, T.
Carbon emission and management of China's power generation
com Abstract - Electricity is a basic necessary ingredient for modern economic growth and electricity sectors and also is the main sources of Carbon dioxides (C02) emission. As the second largest electricity producer and consumer in the world, China has electricity sector as one of the most important sector controlling C02 emission. This study presents the results of a life
Shuyan Caol; Hong Guol; Yufei Gu; Yi Zhang
Assessing Carbon Dioxide Emissions from Energy Use at a University
ERIC Educational Resources Information Center
Purpose: The purpose of this paper is to assess the carbon dioxide emissions associated with electric, HVAC, and hot water use from a US university. Design/methodology/approach: First, the total on-campus electrical, natural gas and oil consumption for an entire year was assessed. For each category of energy use, the carbon associated withů
Riddell, William; Bhatia, Krishan Kumar; Parisi, Matthew; Foote, Jessica; Imperatore, John, III
Field emission from hybrid diamond-like carbon and carbon nanotube composite structures.
A thin diamond-like carbon (DLC) film was deposited onto a densely packed "forest" of vertically aligned multiwalled carbon nanotubes (VACNT). DLC deposition caused the tips of the CNTs to clump together to form a microstructured surface. Field-emission tests of this new composite material show the typical low threshold voltages for carbon nanotube structures (2 V ?m(-1)) but with greatly increased emission current, better stability, and longer lifetime. PMID:24224845
Zanin, H; May, P W; Hamanaka, M H M O; Corat, E J
Energy use and carbon dioxide emissions in the steel sector in key developing countries
Iron and steel production consumes enormous quantities of energy, especially in developing countries where outdated, inefficient technologies are still used to produce iron and steel. Carbon dioxide emissions from steel production, which range between 5 and 15% of total country emissions in key developing countries (Brazil, China, India, Mexico, and South Africa), will continue to grow as these countries develop and as demand for steel products such as materials, automobiles, and appliances increases. In this report, we describe the key steel processes, discuss typical energy-intensity values for these processes, review historical trends in iron and steel production by process in five key developing countries, describe the steel industry in each of the five key developing countries, present international comparisons of energy use and carbon dioxide emissions among these countries, and provide our assessment of the technical potential to reduce these emissions based on best-practice benchmarking. Using a best practice benchmark, we find that significant savings, in the range of 33% to 49% of total primary energy used to produce steel, are technically possible in these countries. Similarly, we find that the technical potential for reducing intensities of carbon dioxide emissions ranges between 26% and 49% of total carbon dioxide emissions from steel production in these countries.
Price, L.K.; Phylipsen, G.J.M.; Worrell, E.
Prospects for international trade in environmental services: An analysis of international carbon emission off-sets
This dissertation presents a case study analysis in which the costs to a US electric utility of reducing its carbon dioxide (CO{sub 2}) emissions are compared with the costs of carbon-saving forestry projects in Costa Rica and Guatemala. The results show that a large electric utility in the south-central US would find it relatively inexpensive, even profitable given a conducive regulatory treatment, to reduce its CO{sub 2} emissions by a few percent over the next ten years, through direct investment in energy end-use efficiency improvements. In comparison, the costs of the forestry projects studied in Central America range from $1/TC to a worst-case value of about $55/TC, with most project costs between $5 and $13/TC, depending on the type of project, the climate, and the opportunity cost of land. The total amount of CO{sub 2} storage potential is significant, about 100 million tons per country, but not enough to suggest that forestry can offset more than a few percent of global CO{sub 2} emissions from fossil fuel use. These case studies suggest that international trade in the environmental service of reducing global CO{sub 2} accumulation could have significant economic and ecological benefits. A transaction in which a utility pays for forestry projects in exchange for credit against an emission reduction policy is an example of an international carbon emission offset (ICEO). ICEO's could provide a currency for funding carbon-saving services as a way to comply with national policies to reduce CO{sub 2} emissions, as long as compliance is allowed through investments in other countries. This type of North-South transfer is necessary to reconcile economic efficiency and international equity, because of the disparity between the national allocations of responsibility for greenhouse gas emissions and opportunities for emission reductions.
Swisher, J.N.
Solid Fuel - Oxygen Fired Combustion for Production of Nodular Reduced Iron to Reduce CO2 Emissions and Improve Energy Efficiencies
The current trend in the steel industry is an increase in iron and steel produced in electric arc furnaces (EAF) and a gradual decline in conventional steelmaking from taconite pellets in blast furnaces. In order to expand the opportunities for the existing iron ore mines beyond their blast furnace customer base, a new material is needed to satisfy the market demands of the emerging steel industry while utilizing the existing infrastructure and materials handling capabilities. This demand creates opportunity to convert iron ore or other iron bearing materials to Nodular Reduced Iron (NRI) in a recently designed Linear Hearth Furnace (LHF). NRI is a metallized iron product containing 98.5 to 96.0% iron and 2.5 to 4% C. It is essentially a scrap substitute with little impurity that can be utilized in a variety of steelmaking processes, especially the electric arc furnace. The objective of this project was to focus on reducing the greenhouse gas emissions (GHG) through reducing the energy intensity using specialized combustion systems, increasing production and the use of biomass derived carbon sources in this process. This research examined the use of a solid fuel-oxygen fired combustion system and compared the results from this system with both oxygen-fuel and air-fuel combustion systems. The solid pulverized fuels tested included various coals and a bio-coal produced from woody biomass in a specially constructed pilot scale torrefaction reactor at the Coleraine Minerals Research Laboratory (CMRL). In addition to combustion, the application of bio-coal was also tested as a means to produce a reducing atmosphere during key points in the fusion process, and as a reducing agent for ore conversion to metallic iron to capture the advantage of its inherent reduced carbon footprint. The results from this study indicate that the approaches taken can reduce both greenhouse gas emissions and the associated energy intensity with the Linear Hearth Furnace process for converting iron ore to metallic iron nodules. Various types of coals including a bio-coal produced though torrefaction can result in production of NRI at reduced GHG levels. The process results coupled with earlier already reported developments indicate that this process technique should be evaluated at the next level in order to develop parameter information for full scale process design. Implementation of the process to full commercialization will require a full cost production analysis and comparison to other reduction technologies and iron production alternatives. The technical results verify that high quality NRI can be produced under various operating conditions at the pilot level.
Donald R. Fosnacht; Richard F. Kiesel; David W. Hendrickson; David J. Englund; Iwao Iwasaki; Rodney L. Bleifuss; Mathew A. Mlinar
Novel coatings to reduce pesticide emissions from chemically treated timbers
SummariesááAluminosilicate zeolite NaY (Si\\/Al=2.6, pore size 0.78nm) and novel mesoporous zeolite-likeNa-MCM-41 (Si\\/Al=2.4, pore size\\u000a 1.2nm) were evaluated as coatings on pesticide treated timber in an effort to reduce airborne emissions of pesticide. Lindane\\u000a (?-hexachlorocyclohexane) was applied as 10% (w\\/w) solution in toluene to blocks of Pinus Sylvestris at a coverage of 245cm3\\/m2. Coatings of activated Nay, non-activated (wet) NaY or
T. A. Morris; K. Huddersman
Fabrication and field emission properties of carbon nanotubes
NASA Astrophysics Data System (ADS)
Research on the area of the fabrication of carbon nanotubes is fundamental and critical to the entire subject of carbon nanotubes. This dissertation describes an experiment to fabricate carbon nanotubes by the method of Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) and the electron field emission properties of carbon nanotubes. A MPECVD system was built and used to fabricate the vertical aligned carbon nanotube film. Scanning electron microscope (SEM), Raman spectroscopy and transmission electron microscopy (TEM) were used to characterize the as-grown carbon nanotube samples. By using a metal-containing diblock copolymer catalyst, carbon nanotubes with a diameter of 4 to 7 nm were synthesized. The effect of growth parameters was studied and these parameters were optimized. The growth of high density (ś 109/cm2) and large coverage area (ś 1 cm2) carbon nanotube film on glass substrate at low growth temperature was realized. Based on a series of experiments, the effects of oxygen atoms and Ti/N underlayer on the growth were studied. A series of experiments were evaluated to characterize the field emission properties of the various carbon nanotube cathodes. A simple technique of scratching the pattern surface by a cotton swab was found effective to activate more carbon nanotubes to emit. By using the techniques of photolithography and shadow mask, various carbon nanotube patterns were achieved in order to obtain high emission current density and a low threshold electric field. The lowest threshold electric field was found to be 2.3 V/um. The highest current density was found to be 2.2 mA/cm2 when the electric field was 4.7 V/um. Our work shows that it is feasible to provide greater control over the fabrication of carbon nanotubes so that more obstacles in the broad application of carbon nanotubes can be overcome.
Wang, Peng
Limestone injection reduces SO2 and NO /SUB x/ emissions
The phases of Foster Wheeler's programs are presented by which the company developed a less complex low-NO /SUB x/ burner. Two phases involved assessing the potential of premixing limestone with coal to reduce SO2, and evaluating a new method of in-burner sorbent injection. Upper furnace injection of limestone was also evaluated by Conoco at the DuPont facility. The article reports that emission of SO2 was reduced by approximately 50% at a calcium: sulfur mole ratio of 2.5. However, the boiler had to be operated at 20% below full load to achieve the same level of sulfur capture achieved at maximum load with in-burner injection.
Vatsky, J.; Schindler, E.S.
HynolŚAn economical process for methanol production from biomass and natural gas with reduced CO 2 emission
The Hynol process is proposed to meet the demand for an economical process for methanol production with reduced CO2 emission. This new process consists of three reaction steps: (a) hydrogasification of biomass, (b) steam reforming of the produced gas with additional natural gas feedstock, and (c) methanol synthesis of the hydrogen and carbon monoxide produced during the previous two steps.
Yuanji Dong; Meyer Steinberg
Hestia Software Measures Urban Carbon Dioxide Emissions
NSDL National Science Digital Library
This short video describes the Hestia project - a software tool and data model that provide visualizations of localized CO2 emissions from residential, commercial, and vehicle levels, as well as day versus night comparisons, in the city of Indianapolis.
Gurney, Kevin; Sustainability, Asu G.
Green emission in carbon doped ZnO films
NASA Astrophysics Data System (ADS)
The emission behavior of C-doped ZnO films, which were prepared by implantation of carbon into ZnO films, is investigated. Orange/red emission is observed for the films with the thickness of 60-100 nm. However, the film with thickness of 200 nm shows strong green emission. Further investigations by annealing bulk ZnO single crystals under different environments, i.e. Ar, Zn or C vapor, indicated that the complex defects based on Zn interstitials are responsible for the strong green emission. The existence of complex defects was confirmed by electron spin resonance (ESR) and low temperature photoluminescence (PL) measurement.
Tseng, L. T.; Yi, J. B.; Zhang, X. Y.; Xing, G. Z.; Fan, H. M.; Herng, T. S.; Luo, X.; Ionescu, M.; Ding, J.; Li, S.
Carbon Dioxide Emission Factors for Coal
The Energy Information Administration (EIA) has developed factors for estimating the amount of carbon dioxide emitted, accounting for differences among coals, to reflect the changing "mix" of coal in U.S. coal consumption.
William Watson
Propagation of uncertainty in carbon emission scenarios through the global carbon cycle
The authors used the GLOCO model, which is a carbon cycling model that considers seven terrestrial biomes, two oceans and one atmosphere, to evaluate the rise in atmospheric CO[sub 2] concentration, (pCO[sub 2]) and the partitioning of carbon to the global compartments (ocean, atmosphere and terrestrial) as a function of time for a number of possible anthropogenic carbon emission scenarios, based on different energy policies as developed by the Energy Modeling Forum (EMF-12). The authors then evaluated the possible uncertainty in carbon emission scenarios and the propagation of this uncertainty in carbon emission scenarios and the propagation of this uncertainty throughout the model to obtain an envelope for the rise in pCO[sub 2]. Large fluctuations in the input signal are smoothed by the carbon cycle, resulting in more than a four-fold reduction in uncertainty in the output signal (pCO[sub 2]). In addition, they looked at the effect that other model variables have on the pCO[sub 2] envelope, specifically the ratio of carbon to nitrogen in the emissions. The carbon to nitrogen ratio (C:N) will vary throughout the next century depending on the mix on energy sources chosen. More nitrogen in the emissions can produce a cofertilization effect in the terrestrial biomes, which would lead to sequestration of additional carbon. The uncertainty in C:N will enlarge the pCO[sub 2] uncertainty envelope by up to 20 ppm.
Keller, A.A.; Goldstein, R.A. (Electric Power Research Inst., Palo Alto, CA (United States))
RESULTS FROM THE U.S. DOE 2006 SAVE ENERGY NOW ASSESSMENT INITIATIVE: DOE's Partnership with U.S. Industry to Reduce Energy Consumption, Energy Costs, and Carbon Dioxide Emissions
In the wake of Hurricane Katrina and other severe storms in 2005, natural gas supplies were restricted, prices rose, and industry sought ways to reduce its natural gas use and costs. In October 2005, U.S. Department of Energy (DOE) Energy Secretary Bodman launched his Easy Ways to Save Energy campaign with a promise to provide energy assessments to 200 of the largest U.S. manufacturing plants. A major thrust of the campaign was to ensure that the nation's natural gas supplies would be adequate for all Americans, especially during home heating seasons. In a presentation to the National Press Club on October 3, 2005, Secretary Bodman said: 'America's businesses, factories, and manufacturing facilities use massive amounts of energy. To help them during this period of tightening supply and rising costs, our Department is sending teams of qualified efficiency experts to 200 of the nation's most energy-intensive factories. Our Energy Saving Teams will work with on-site managers on ways to conserve energy and use it more efficiently.' DOE's Industrial Technologies Program (ITP) responded to the Secretary's campaign with its Save Energy Now initiative, featuring a new and highly cost-effective form of energy assessments. The approach for these assessments drew heavily on the existing resources of ITP's Technology Delivery component. Over the years, ITP-Technology Delivery had worked with industry partners to assemble a suite of respected software decision tools, proven assessment protocols, training curricula, certified experts, and strong partnerships for deployment. Because of the program's earlier activities and the resources that had been developed, ITP was prepared to respond swiftly and effectively to the sudden need to promote improved industrial energy efficiency. Because of anticipated supply issues in the natural gas sector, the Save Energy Now initiative strategically focused on natural gas savings and targeted the nation's largest manufacturing plants--those that consume a total of 1 trillion British thermal units (Btu) or more annually. The approximately 6800 U.S. facilities that fall into this category collectively account for about 53% of all energy consumed by industry in the United States. The 2006 Save Energy Now energy assessments departed from earlier DOE plant assessments by concentrating solely on steam and process heating systems, which are estimated to account for approximately 74% of all natural gas use for manufacturing. The assessments also integrated a strong training component designed to teach industrial plant personnel how to use DOE's steam or process heating opportunity assessment software tools. This approach had the advantages of promoting strong buy-in of plant personnel for the assessment and its outcomes and preparing them better to independently replicate the assessment process at the company's other facilities. The Save Energy Now initiative also included provisions to help plants that applied for but did not qualify for assessments (based on the 1 trillion Btu criterion). Services offered to these plants included (1) an assessment by one of DOE's 26 university-based Industrial Assessment Centers (IACs), (2) a telephone consultation with a systems expert at the DOE's Energy Efficiency and Renewable Energy Information Center, or (3) other technical materials and services available through ITP (e.g., the Save Energy Now CD). By the end of 2006, DOE had completed all 200 of the promised assessments, identifying potential natural gas savings of more than 50 trillion Btu and energy cost savings of about $500 million. These savings, if fully implemented, could reduce CO2 emissions by 4.04 million metric tons annually. These results, along with the fact that a large percentage of U.S. energy is used by a relatively small number of very large plants, clearly suggest that assessments are an expedient and cost-effective way to significantly affect large amounts of energy use. Building on the success of the 2006 initiative, ITP has expanded the effort in 2007 with the goal of conducting 250 more asse
Wright, Anthony L [ORNL; Martin, Michaela A [ORNL; Gemmer, Bob [U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy; Scheihing, Paul [U.S. Department of Energy, Industrial Technologies Program; Quinn, James [U.S. Department of Energy
Very Stable Electron Field Emission From Strontium Titanate Coated Carbon Nanotube Matrices With Low Emission Thresholds
PMMA-STO-CNT matrices were created by opened-tip vertically-aligned multiwalled carbon nanotubes (VA-MWCNTs) with conformal coating of strontium titanate and Poly(methyl methacrylate). Emission threshold of 0.8 V/?m was demonstrated, about five-fold lower than that of the as-grown VAMWCNTs. Theoretical simulation and modeling suggest that PMMA-STO-CNT matrices have suppressed screening effects and Coulombsĺ repulsion forces between electrons in adjacent CNTs, leading to low emission threshold, high emission density, and prolong emission stability. These findings are important for practical application of VA-MWCNTs in field emission devices.
Pandey, Archana; Prasad, Abhishek; Moscatello, Jason; Engelhard, Mark H.; Wang, Chong M.; Yap, Yoke K.
Systems accounting for energy consumption and carbon emission by building
NASA Astrophysics Data System (ADS)
The method of systems accounting for overall energy consumption and carbon emission induced by a building is illustrated in terms of a combination of process and input-output analyses with a concrete procedure to cover various material, equipment, energy and manpower inputs. A detailed case study based on raw project data in the Bill of Quantities (BOQ) is performed for the structure engineering of the landmark buildings in E-town, Beijing (Beijing Economic-Technological Development Area). Based on the embodied energy and carbon emission intensity database for the Chinese economy in 2007, the energy consumption and the carbon emission of the structure engineering of the case buildings are quantified as 4.15E+14 J and 4.83E+04 t CO2 Eq., corresponding to intensities of 6.91E+09 J/m2 and 0.81 t CO2 Eq./m2 floor area. Steel and concrete contribute respectively about 50% and 30% of the energy consumption and the carbon emission, as a result of the reinforced-concrete structure of the case buildings. Materials contribute up to about 90% of the total energy consumption and carbon emission, in contrast to manpower, energy and equipment around 8%, 1% and 0.1%, respectively.
Shao, Ling; Chen, G. Q.; Chen, Z. M.; Guo, Shan; Han, M. Y.; Zhang, Bo; Hayat, T.; Alsaedi, A.; Ahmad, B.
Reducing supply chain costs and carbon footprint during product design
Manufacturing companies continue to struggle with simultaneously assessing and reducing supply chain costs and carbon footprint early in the design process as consumers demand more sustainable products. An integrated product design-supply chain design approach is explored and applied to bicycle design. It is shown that the approach can successfully inform decision-makers on the consequences of their choices even when component
Ming-Chuan Chiu; Ahmed J. Alsaffar; GŘl E. Okudan; Karl R. Haapala
Historical warming reduced due to enhanced land carbon uptake.
Previous studies have demonstrated the importance of enhanced vegetation growth under future elevated atmospheric CO2 for 21st century climate warming. Surprisingly no study has completed an analogous assessment for the historical period, during which emissions of greenhouse gases increased rapidly and land-use changes (LUC) dramatically altered terrestrial carbon sources and sinks. Using the Geophysical Fluid Dynamics Laboratory comprehensive Earth System Model ESM2G and a reconstruction of the LUC, we estimate that enhanced vegetation growth has lowered the historical atmospheric CO2 concentration by 85 ppm, avoiding an additional 0.31 ▒ 0.06 ░C warming. We demonstrate that without enhanced vegetation growth the total residual terrestrial carbon flux (i.e., the net land flux minus LUC flux) would be a source of 65-82 Gt of carbon (GtC) to atmosphere instead of the historical residual carbon sink of 186-192 GtC, a carbon saving of 251-274 GtC. PMID:24062452
Shevliakova, Elena; Stouffer, Ronald J; Malyshev, Sergey; Krasting, John P; Hurtt, George C; Pacala, Stephen W
Performance of additives in reducing ammonia emissions from cow slurry.
National Technical Information Service (NTIS)
Ammonia emissions contribute substantially to environmental pollution and cause severe acidification. In Sweden, 20-25% of the total ammonia emission derives from manure in animal buildings. One technique to decrease ammonia emissions from animal building...
M. Andersson
Dielectric barrier discharge carbon atomic emission spectrometer: universal GC detector for volatile carbon-containing compounds.
It was found that carbon atomic emission can be excited in low temperature dielectric barrier discharge (DBD), and an atmospheric pressure, low power consumption, and compact microplasma carbon atomic emission spectrometer (AES) was constructed and used as a universal and sensitive gas chromatographic (GC) detector for detection of volatile carbon-containing compounds. A concentric DBD device was housed in a heating box to increase the plasma operation temperature to 300 ░C to intensify carbon atomic emission at 193.0 nm. Carbon-containing compounds directly injected or eluted from GC can be decomposed, atomized, and excited in this heated DBD for carbon atomic emission. The performance of this new optical detector was first evaluated by determination of a series of volatile carbon-containing compounds including formaldehyde, ethyl acetate, methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol, and absolute limits of detection (LODs) were found at a range of 0.12-0.28 ng under the optimized conditions. Preliminary experimental results showed that it provided slightly higher LODs than those obtained by GC with a flame ionization detector (FID). Furthermore, it is a new universal GC detector for volatile carbon-containing compounds that even includes those compounds which are difficult to detect by FID, such as HCHO, CO, and CO2. Meanwhile, hydrogen gas used in conventional techniques was eliminated; and molecular optical emission detection can also be performed with this GC detector for multichannel analysis to improve resolution of overlapped chromatographic peaks of complex mixtures. PMID:24328147
Han, Bingjun; Jiang, Xiaoming; Hou, Xiandeng; Zheng, Chengbin
Estimated carbon dioxide emissions from tropical deforestation improved by carbon-density maps
NASA Astrophysics Data System (ADS)
Deforestation contributes 6-17% of global anthropogenic CO2 emissions to the atmosphere. Large uncertainties in emission estimates arise from inadequate data on the carbon density of forests and the regional rates of deforestation. Consequently there is an urgent need for improved data sets that characterize the global distribution of aboveground biomass, especially in the tropics. Here we use multi-sensor satellite data to estimate aboveground live woody vegetation carbon density for pan-tropical ecosystems with unprecedented accuracy and spatial resolution. Results indicate that the total amount of carbon held in tropical woody vegetation is 228.7PgC, which is 21% higher than the amount reported in the Global Forest Resources Assessment 2010 (ref. ). At the national level, Brazil and Indonesia contain 35% of the total carbon stored in tropical forests and produce the largest emissions from forest loss. Combining estimates of aboveground carbon stocks with regional deforestation rates we estimate the total net emission of carbon from tropical deforestation and land use to be 1.0PgCyr-1 over the period 2000-2010--based on the carbon bookkeeping model. These new data sets of aboveground carbon stocks will enable tropical nations to meet their emissions reporting requirements (that is, United Nations Framework Convention on Climate Change Tier 3) with greater accuracy.
Baccini, A.; Goetz, S. J.; Walker, W. S.; Laporte, N. T.; Sun, M.; Sulla-Menashe, D.; Hackler, J.; Beck, P. S. A.; Dubayah, R.; Friedl, M. A.; Samanta, S.; Houghton, R. A.
Fire suppression and fuels treatment effects on mixed-conifer carbon stocks and emissions.
Depending on management, forests can be an important sink or source of carbon that if released as CO2 could contribute to global warming. Many forests in the western United States are being treated to reduce fuels, yet the effects of these treatments on forest carbon are not well understood. We compared the immediate effects of fuels treatments on carbon stocks and releases in replicated plots before and after treatment, and against a reconstruction of active-fire stand conditions for the same forest in 1865. Total live-tree carbon was substantially lower in modern fire-suppressed conditions (and all of the treatments) than the same forest under an active-fire regime. Although fire suppression has increased stem density, current forests have fewer very large trees, reducing total live-tree carbon stocks and shifting a higher proportion of those stocks into small-diameter, fire-sensitive trees. Prescribed burning released 14.8 Mg C/ha, with pre-burn thinning increasing the average release by 70% and contributing 21.9-37.5 Mg C/ha in milling waste. Fire suppression may have incurred a double carbon penalty by reducing stocks and contributing to emissions with fuels-treatment activities or inevitable wildfire combustion. All treatments reduced fuels and increased fire resistance, but most of the gains were achieved with understory thinning, with only modest increases in the much heavier overstory thinning. We suggest modifying current treatments to focus on reducing surface fuels, actively thinning the majority of small trees, and removing only fire-sensitive species in the merchantable, intermediate size class. These changes would retain most of the current carbon-pool levels, reduce prescribed burn and potential future wildfire emissions, and favor stand development of large, fire-resistant trees that can better stabilize carbon stocks. PMID:19769088
North, Malcolm; Hurteau, Matthew; Innes, James
Carbon monoxide emission from small galaxies
NASA Technical Reports Server (NTRS)
A search was conducted for J = 1 yields 0 CO emission from 22 galaxies, detecting half, as part of a survey to study star formation in small to medium size galaxies. Although substantial variation was found in the star formation efficiencies of the sample galaxies, there is no apparent systematic trend with galaxy size.
Thronson, Harley A., Jr.; Bally, John
Energy and Carbon Emissions: Country Studies.
National Technical Information Service (NTIS)
In response to the Kyoto Protocol for preventing global warming, signed in February 2005, the Kyoto Protocol Target Achievement Plan was developed in March 2006. In this plan, CO2 emission reduction targets to be achieved in FY 2010 was set in each sector...
S. Murakami M. D. Levine H. Yoshinovin T. Inoue T. Ikaga
Synthesis and thermionic emission properties of graphitic carbon nanofibres supported on Si wafers or carbon felt
NASA Astrophysics Data System (ADS)
Preparation procedures and thermionic emission properties of graphitic carbon nanofibres (GCNFs) supported on Si wafer or commercial carbon felt supports are reported. GCNF/native-oxide Si wafer, GCNF/oxidized Si wafer, GCNF/Ni-coated Si wafer and GCNF/carbon felt nanocomposites are obtained by growing GCNFs from growth catalyst nanoparticles supported on these supports. Narrow herringbone GCNF/SiO2/carbon felt mats are prepared from growth catalyst nanoparticles supported on fumed silica flakes. Due to weak GCNF-to-support binding in GCNF/Si wafer mats, GCNF/carbon felt mats and GCNF/SiO2/carbon felt mats, mechanical loss of the GCNF component is facile. However, carbothermal reduction of GCNF/SiO2/carbon felt nanocomposites affords mechanically robust GCNF/SiC/carbon felt mats. Thermionic electron energy distribution profiles recorded for these new nanofibre compositions indicate classic free-electron emission with estimated work functions (4.25-4.91 eV) slightly lower than those observed for un-doped graphite or carbon nanotubes. Electron energy distributions along the low energy leading region of the profiles display a cascade of emission peaks equally spaced by ca 0.014 eV, tentatively attributed to electron emission from localized GCNF edge sites.
Li, Jiang; Robinson, Vance S.; Liu, Yang; Lu, Weijie; Fisher, Timothy S.; Lukehart, Charles M.
Carbon-containing cathodes for enhanced electron emission
A cathode has electropositive atoms directly bonded to a carbon-containing substrate. Preferably, the substrate comprises diamond or diamond-like (sp.sup.3) carbon, and the electropositive atoms are Cs. The cathode displays superior efficiency and durability. In one embodiment, the cathode has a negative electron affinity (NEA). The cathode can be used for field emission, thermionic emission, or photoemission. Upon exposure to air or oxygen, the cathode performance can be restored by annealing or other methods. Applications include detectors, electron multipliers, sensors, imaging systems, and displays, particularly flat panel displays.
Cao, Renyu (Cupertino, CA); Pan, Lawrence (Pleasanton, CA); Vergara, German (Madrid, ES); Fox, Ciaran (Los Altos, CA)
A Carbon Nanotube Field-Emission Electron Source
A high-intensity electron gun based on field emission from a film of aligned carbon nanotubes has been made. The gun consists of a nanotube film with a 1-millimeter-diameter grid about 20 micrometers above it. Field-emission current densities of about 0.1 milliampere per square centimeter were observed for applied voltages as low as 200 volts, and current densities greater than 100
Walt A. de Heer; A. Chatelain; D. Ugarte
Field emission from non-uniform carbon nanotube arrays
Regular arrays of carbon nanotubes (CNTs) are frequently used in studies on field emission. However, non-uniformities are always present like dispersions in height, radius, and position. In this report, we describe the effect of these non-uniformities in the overall emission current by simulation. We show that non-uniform arrays can be modeled as a perfect array multiplied by a factor that is a function of the CNTs spacing.
Field emission from non-uniform carbon nanotube arrays.
Regular arrays of carbon nanotubes (CNTs) are frequently used in studies on field emission. However, non-uniformities are always present like dispersions in height, radius, and position. In this report, we describe the effect of these non-uniformities in the overall emission current by simulation. We show that non-uniform arrays can be modeled as a perfect array multiplied by a factor that is a function of the CNTs spacing. PMID:23841961
Dall'agnol, Fernando F; den Engelsen, Daniel
Synthesis, Structure and Field Emission of Carbon Nanotubes
Multiwall and single-wall nanotubes were produced by carbon arc discharge in helium, and their structures were investigated by electron microscopy. Field emission from (1) as-grown multiwall nanotubes (MWNTs), (2) purified MWNTs and (3) purified single-wall nanotubes (SWNTs) was investigated by field emission microscopy. Of the three kinds of nanotubes studied, purified MWNTs whose tips are open provided the highest current
Yahachi Saito; Ryou Mizushima; Toshihiko Tanaka; Kazuyuki Tohji; Kunio Uchida; Motoo Yumura; Sashiro Uemura
Electricity generation: options for reduction in carbon emissions.
Historically, the bulk production of electricity has been achieved by burning fossil fuels, with unavoidable gaseous emissions, including large quantities of carbon dioxide: an average-sized modern coal-burning power station is responsible for more than 10 Mt of CO(2) each year. This paper details typical emissions from present-day power stations and discusses the options for their reduction. Acknowledging that the cuts achieved in the past decade in the UK CO(2) emissions have been achieved largely by fuel switching, the remaining possibilities offered by this method are discussed. Switching to less-polluting fossil fuels will achieve some measure of reduction, but the basic problem of CO(2) emissions continues. Of the alternatives to fossil fuels, only nuclear power represents a zero-carbon large-scale energy source. Unfortunately, public concerns over safety and radioactive waste have still to be assuaged. Other approaches include the application of improved combustion technology, the removal of harmful gases from power-station flues and the use of waste heat to improve overall power-station efficiency. These all have a part to play, but many consider our best hope for emissions reduction to be the use of renewable energy. The main renewable energy contenders are assessed in this paper and realistic estimates of the contribution that each could provide are indicated. It appears that, in the time-scale envisaged by planners for reduction in CO(2) emission, in many countries renewable energy will be unlikely to deliver. At the same time, it is worth commenting that, again in many countries, the level of penetration of renewable energy will fall short of the present somewhat optimistic targets. Of renewable options, wind energy could be used in the short to medium term to cover for thermal plant closures, but for wind energy to be successful, the network will have to be modified to cope with wind's intermittent nature. Globally, hydroelectricity is currently the largest developed source of renewable electricity, but future large-scale projects will probably be limited to the less-developed world: the best schemes in the developed countries have already been exploited. Wave and tidal can be looked on as medium- to long-term generators of electricity, as their respective industries are not as mature as competing renewable resources. Municipal solid-waste combustion and landfill gas technologies can also be seen as short term, as can their rural equivalents, agriculture and forestry waste. Any widespread exploitation of renewable energy will depend on being able to transmit the energy from source to point of use, so the implications for the electrical network from the penetration of substantial levels of renewable energy are presented. Effective management of renewable energy installations will require technical assessment of the range of exploitation strategies, to compare local production of, say, hydrogen and the more traditional transmission of electricity. Such resources will have to compete with others in any national, or grid, system and detailed economic analysis will be necessary to determine the deployment that best fits the trading regime under which the energy will be sold. Consideration will also be necessary to determine how best to control the introduction of this radically new resource such that it does not attract punitive cost overheads until it is mature enough to cope. Finally, it is inescapable that nuclear power is a proven technology that could take its place in any future generation portfolio. Unfortunately, suspicion and mistrust surround waste management and radioactivity release. Unless this is overcome, the lack of confidence engendered by this public mistrust may result in few, if any, new nuclear power stations being built. In the event of that decision, it is difficult to see how CO(2) levels can be significantly reduced: the irony is that nuclear energy may emerge as environmentally essential. PMID:12460490
Whittington, H W
Changes in Carbon Emissions in Colombian Savannas Derived From Recent Land use and Land Cover Change
The global contribution of carbon emissions from land use dynamics and change to the global carbon (C) cycle is still uncertain, a major concern in global change modeling. Carbon emission from fires in the tropics is significant and represents 9% of the net primary production, and 50% of worldwide C emissions from fires are attributable to savanna fires. Such emissions
A. Etter; A. Sarmiento
Carbon emissions risk map from deforestation in the tropical Amazon
NASA Astrophysics Data System (ADS)
Assis, Pedro Valle This work aims to estimate the carbon emissions from tropical deforestation in the Brazilian Amazon associated to the risk assessment of future land use change. The emissions are estimated by incorporating temporal deforestation dynamics, accounting for the biophysical and socioeconomic heterogeneity in the region, as well secondary forest growth dynamic in abandoned areas. The land cover change model that supported the risk assessment of deforestation, was run based on linear regressions. This method takes into account spatial heterogeneity of deforestation as the spatial variables adopted to fit the final regression model comprise: environmental aspects, economic attractiveness, accessibility and land tenure structure. After fitting a suitable regression models for each land cover category, the potential of each cell to be deforested (25x25km and 5x5 km of resolution) in the near future was used to calculate the risk assessment of land cover change. The carbon emissions model combines high-resolution new forest clear-cut mapping and four alternative sources of spatial information on biomass distribution for different vegetation types. The risk assessment map of CO2 emissions, was obtained by crossing the simulation results of the historical land cover changes to a map of aboveground biomass contained in the remaining forest. This final map represents the risk of CO2 emissions at 25x25km and 5x5 km until 2020, under a scenario of carbon emission reduction target.
Ometto, J.; Soler, L. S.; Assis, T. D.; Oliveira, P. V.; Aguiar, A. P.
Using infrastructure optimization to reduce greenhouse gas emissions from oil sands extraction and processing.
The Alberta oil sands are a significant source of oil production and greenhouse gas emissions, and their importance will grow as the region is poised for decades of growth. We present an integrated framework that simultaneously considers economic and engineering decisions for the capture, transport, and storage of oil sands CO(2) emissions. The model optimizes CO(2) management infrastructure at a variety of carbon prices for the oil sands industry. Our study reveals several key findings. We find that the oil sands industry lends itself well to development of CO(2) trunk lines due to geographic coincidence of sources and sinks. This reduces the relative importance of transport costs compared to nonintegrated transport systems. Also, the amount of managed oil sands CO(2) emissions, and therefore the CCS infrastructure, is very sensitive to the carbon price; significant capture and storage occurs only above 110$/tonne CO(2) in our simulations. Deployment of infrastructure is also sensitive to CO(2) capture decisions and technology, particularly the fraction of capturable CO(2) from oil sands upgrading and steam generation facilities. The framework will help stakeholders and policy makers understand how CCS infrastructure, including an extensive pipeline system, can be safely and cost-effectively deployed. PMID:23276202
Middleton, Richard S; Brandt, Adam R
Global carbon dioxide emissions from inland waters.
Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8(+0.25)(-0.25)? petagrams of carbon (Pg?C) per year from streams and rivers and 0.32(+0.52)(-0.26)? Pg?C?yr(-1) from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1?Pg?C?yr(-1) is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally. PMID:24256802
Raymond, Peter A; Hartmann, Jens; Lauerwald, Ronny; Sobek, Sebastian; McDonald, Cory; Hoover, Mark; Butman, David; Striegl, Robert; Mayorga, Emilio; Humborg, Christoph; Kortelainen, Pirkko; DŘrr, Hans; Meybeck, Michel; Ciais, Philippe; Guth, Peter
Improvement of carbon nanotube field emission properties by ultrasonic nanowelding
NASA Astrophysics Data System (ADS)
Ultrasonic nanowelding was used to improve the field emission properties of carbon nanotube (CNT) cathodes. The CNTs were deposited on the Ti-coated glass substrate by electrophoretic deposition. By pressing CNTs against metal (Ti) substrate under a vibrating force at ultrasonic frequency, a reliable and low resistance contact was obtained between CNTs and Ti. The scanning electron microscopy results show that CNTs are embedded into the metal substrate and act as stable field emitters. The welded cathode demonstrates an excellent field emission with high emission current density and good current stability.
Zhao, Bo; Yadian, Boluo; Chen, Da; Xu, Dong; Zhang, Yafei
nanotubes de carbone : Útat de l'art et applications Electron field emission from carbon nanotubes
Carbon nanotubes (CNT) have recently emerged as a promising class of electron field emitters. They have a low threshold electric field for emission and a high emission current density which make them attractive for technological applications. In this article we review recent progress on understanding of CNT field emitters and discuss issues related to applications of CNT-
Yuan Cheng; Otto Zhou
Atmospheric monitoring for fugitive emissions from geological carbon storage
NASA Astrophysics Data System (ADS)
We present a multi-year record of continuous atmospheric CO2 and CH4 concentration measurements, flask sampling (for CO2, CH4, N2O, ?13CO2 and SF6) and CO2 flux measurements at the CO2CRC Otway Project (http://www.co2crc.com.au/otway/), a demonstration site for geological storage of CO2 in south-western Victoria, Australia. The measurements are used to develop atmospheric methods for operational monitoring of large scale CO2 geological storage. Characterization of emission rates ideally requires concentration measurements upwind and downwind of the source, along with knowledge of the atmospheric turbulence field. Because only a single measurement location was available for much of the measurement period, we develop techniques to filter the record and to construct a ';pseudo-upwind' measurement from our dataset. Carbon dioxide and methane concentrations were filtered based on wind direction, downward shortwave radiation, atmospheric stability and hour-to-hour changes in CO2 flux. These criteria remove periods of naturally high concentration due to the combined effects of biogenic respiration, stable atmospheric conditions and pre-existing sources (both natural and anthropogenic), leaving a reduced data set, from which a fugitive leak from the storage reservoir, the ';(potential) source sector)', could more easily be detected. Histograms of the filtered data give a measure of the background variability in both CO2 and CH4. Comparison of the ';pseudo-upwind' dataset histogram with the ';(potential) source sector' histogram shows no statistical difference, placing limits on leakage to the atmosphere over the preceding two years. For five months in 2011, we ran a true pair of up and downwind CO2 and CH4 concentration measurements. During this period, known rates of gas were periodically released at the surface (near the original injection point). These emissions are clearly detected as elevated concentrations of CO2 and CH4 in the filtered data and in the measured concentration differences across the site. A Bayesian inverse modeling study of the controlled release data accurately retrieved both the location and emission rate of the source. The atmospheric monitoring techniques developed at the Otway Project site are readily transferable to other energy sector developments, such as coal seam gas production, in which fugitive emissions are a concern. Indeed, as the signal to noise is usually better for CH4 than CO2, our monitoring techniques are even more suitable for seeking fugitives from natural gas production.
Loh, Z. M.; Etheridge, D.; Luhar, A.; Leuning, R.; Jenkins, C.
Options for lowering U.S. carbon dioxide emissions
NASA Astrophysics Data System (ADS)
The United States can decrease its emissions of carbon dioxide (CO2) to as much as 35 percent below 1987 levels within the next 25 years by adopting an aggressive package of policies crossing all sectors of the economy. Such emissions reductions will be difficult to achieve and may be costly, but no major technological breakthroughs are needed. In this paper, we identify a ``Tough'' package of energy conservation, energy supply, and forest managment practices to accomplish this level of emissions reductions. We also present a package of cost-effective, ``Moderate'' technical options, which if adopted, would hold CO2 emissions to about 15-percent increase over 1987 levels by 2015. In constrast, if the United State takes not new actions to curb energy use, CO2 emissions will likely rise 50 percent during that time. A variety of Federal policy initiatives will be required to achieve large reductions in U.S. CO2 emissions. Such policy actions will have to include both regulatory ``push'' and market ``pull'' mechanisms--including performance standards, tax incentive programs, carbon-emission or energy taxes, labeling and efficiency ratings, and research, development, and demostration activities.
Bierbaum, Rosina M.; Friedman, Robert M.; Levenson, Howard; Rapoport, Richard D.; Sundt, Nick
Categorization of Scope 3 emissions for streamlined enterprise carbon footprinting.
Many organizations look to carbon footprint protocols for guidance on measuring their greenhouse gas emissions, or carbon footprint. Existing protocols generally require estimation of direct emissions (Scope 1) and emissions from direct purchases of energy (Scope 2), but focus less on indirect emissions upstream and downstream of the supply chain (optional Scope 3). Because on average more than 75% of an industry sector's carbon footprint is attributed to Scope 3 sources, better knowledge of Scope 3 footprints can help organizations pursue emissions mitigation projects not just within their own plants but also across their supply chain. In this work, Scope 3 footprints of U.S. economic sectors are categorized using an Economic Input-Output Life Cycle Assessment (EIO-LCA) model to identify upstream emission sources that are likely to contribute significantly to different sectors' footprints. The portions of the upstream footprint captured by the sector's top-10 upstream suppliers are estimated at 3 different levels of specificity: general economy-wide, industry specific, and sector specific. The results show that enterprises can capture a large portion of their total upstream carbon footprint by collecting full emissions information from only a handful of direct suppliers, and Scope 3 footprint capture rates can be improved considerably by sector-specific categorization. Employee commuting and air transportation may be more important (7%-30%) for the services industries, but should not be a focus of detailed Scope 3 footprint estimates for the manufacturing industries (<1% of the total analyzed footprint). Protocol organizations should actively make more specific Scope 3 guidelines available for their constituents by developing sector-specific categorizations for as many sectors as they feasibly can and create broader industry-specific protocols for others. PMID:20028044
Huang, Y Anny; Weber, Christopher L; Matthews, H Scott
Carbon sequestration and greenhouse gas emissions in urban turf
NASA Astrophysics Data System (ADS)
Undisturbed grasslands can sequester significant quantities of organic carbon (OC) in soils. Irrigation and fertilization enhance CO2 sequestration in managed turfgrass ecosystems but can also increase emissions of CO2 and other greenhouse gases (GHGs). To better understand the GHG balance of urban turf, we measured OC sequestration rates and emission of N2O (a GHG ś 300 times more effective than CO2) in Southern California, USA. We also estimated CO2 emissions generated by fuel combustion, fertilizer production, and irrigation. We show that turf emits significant quantities of N2O (0.1-0.3 g N m-2 yr-1) associated with frequent fertilization. In ornamental lawns this is offset by OC sequestration (140 g C m-2 yr-1), while in athletic fields, there is no OC sequestration because of frequent surface restoration. Large indirect emissions of CO2 associated with turfgrass management make it clear that OC sequestration by turfgrass cannot mitigate GHG emissions in cities.
Townsend-Small, Amy; Czimczik, Claudia I.
Choices in calculating life cycle emissions of carbon containing gases associated with forest derived biofuels
Life cycle studies concerning carbon dioxide emissions associated with biofuels from forests may consider emissions originating in the use of fossil fuels and biogenic emissions. When both types of emissions are considered, emission factors are dependent on choices as to time-frame, land-use scenario, allocation of sequestration and fate of sequestered carbon after fuel wood harvesting. Dependent on such choices life
L. Reijnders; M. A. J Huijbregts
High-resolution mapping of motor vehicle carbon dioxide emissions
NASA Astrophysics Data System (ADS)
fuel-based inventory for vehicle emissions is presented for carbon dioxide (CO2) and mapped at various spatial resolutions (10 km, 4 km, 1 km, and 500 m) using fuel sales and traffic count data. The mapping is done separately for gasoline-powered vehicles and heavy-duty diesel trucks. Emission estimates from this study are compared with the Emissions Database for Global Atmospheric Research (EDGAR) and VULCAN. All three inventories agree at the national level within 5%. EDGAR uses road density as a surrogate to apportion vehicle emissions, which leads to 20-80% overestimates of on-road CO2 emissions in the largest U.S. cities. High-resolution emission maps are presented for Los Angeles, New York City, San Francisco-San Jose, Houston, and Dallas-Fort Worth. Sharp emission gradients that exist near major highways are not apparent when emissions are mapped at 10 km resolution. High CO2 emission fluxes over highways become apparent at grid resolutions of 1 km and finer. Temporal variations in vehicle emissions are characterized using extensive day- and time-specific traffic count data and are described over diurnal, day of week, and seasonal time scales. Clear differences are observed when comparing light- and heavy-duty vehicle traffic patterns and comparing urban and rural areas. Decadal emission trends were analyzed from 2000 to 2007 when traffic volumes were increasing and a more recent period (2007-2010) when traffic volumes declined due to recession. We found large nonuniform changes in on-road CO2 emissions over a period of ~5 years, highlighting the importance of timely updates to motor vehicle emission inventories.
McDonald, Brian C.; McBride, Zoe C.; Martin, Elliot W.; Harley, Robert A.
Field emission characteristics of regular arrays of carbon nanotubes.
The developments of electronic devices based on micron-sized vacuum electron sources during the last decades have triggered intense research on highly efficient carbon based thin film electron emitters. The synthesis of massive arrays of carbon nanotubes that are oriented on patterned Fe catalyst deposited on quartz substrates is reported. The well-ordered nanotubes can be used as electron field emission arrays. Scaling up of the synthesis process should be entirely compatible with the existing semiconductor processes, and should allow the development of nanotubes devices integrated into future technology. The emission from carbon nanotubes array is explained by Fowler-Nordheim tunneling of electrons from tip-like structures in the nanometer range, which locally amplify the applied field by the field enhancement factor beta. We found that the low pressure chemical vapour deposition (LPCVD) system can produce nanotubes capable of excellent emission currents at lower voltages. The carbon nanotubes array shows good field emission with turn on field E(alpha) = 1.30 V/microm at the current density of 3.50 mA/cm2 with enhancement factor beta = 1.22 x 10(2). PMID:24738452
Al-Ghamdi, A A; Al-Heniti, S; Al-Hazmi, F S; Faidah, Adel S; Shalaan, E; Husain, M
Timing of carbon emissions from global forest clearance
NASA Astrophysics Data System (ADS)
Land-use change, primarily from conventional agricultural expansion and deforestation, contributes to approximately 17% of global greenhouse-gas emissions. The fate of cleared wood and subsequent carbon storage as wood products, however, has not been consistently estimated, and is largely ignored or oversimplified by most models estimating greenhouse-gas emissions from global land-use conversion. Here, we estimate the fate of cleared wood and timing of atmospheric carbon emissions for 169 countries. We show that 30 years after forest clearance the percentage of carbon stored in wood products and landfills ranges from about 0% to 62% globally. For 90 countries, less than 5% of carbon remains after 30 years, whereas 34 countries have more than 25% in storage. Higher storage rates result primarily from a greater percentage of long-lived products such as wood panels and lumber, and tend to occur in countries with predominantly temperate forests. Alternatively, lower storage rates are associated with a greater fraction of non-merchantable wood and more wood used for energy and paper production, which tend to occur in countries with predominantly tropical forests. Hence, the country and fate of cleared wood can considerably affect the timing of greenhouse-gas emissions from forest clearance.
Mason Earles, J.; Yeh, Sonia; Skog, Kenneth E.
The Land Use Planning Imperative: Applying Carbon Emissions Analyses
Reversing global warming is the defining crisis of the 21st century and must be dealt with, in part, by reinventing the built environment. Current land use and planning frameworks are not aligned with scientific models which can aid in the reversal of carbon emissions at the local and regional scale. The disjunction between land use planning and the scientific methodologies
E. N. Bray; G. Havens
Carbon nanotubes: new material applied to field emission display
Field emission characteristics of carbon nanotubes (CNTs) were investigated in this paper. CNTs were produced by the catalytic decomposition of hydrocarbons--propylene on the nickel films. The SEM images showed that CNTs were quite uniform and disordered; the average diameter is about 50 nm. The measurements were performed in a vacuum chamber at the pressure of 10-7 torr. The results showed
Jie Zhu; Dongjun Mao; Anyuan Cao; Bingqing Wei; Ji Liang; Cailu Xu; Dejie Li; Dehai Wu
Precise measurement of prompt photon emission for carbon ion therapy
Proton and carbon ion therapy is an emerging technique used for the treatment of solid cancers. The monitoring of the dose delivered during such treatments is still a matter of research. A possible technique exploits the information provided by single photon emission from nuclear decays induced by the irradiation. This paper reports the measurements of the spectrum and rate of
C. Agodi; F. Bellini; G. A. P. Cirrone; F. Collamati; G. Cuttone; E. De Lucia; M. De Napoli; A. Di Domenico; R. Faccini; F. Ferroni; S. Fiore; P. Gauzzi; E. Iarocci; M. Marafini; I. Mattei; A. Paoloni; V. Patera; L. Piersanti; F. Romano; A. Sarti; A. Sciubba; C. Voena
Field Emission Characteristics of Carbon Nanotubes and Their Applications in Sensors and Devices
NASA Astrophysics Data System (ADS)
FIELD EMISSION CHARACTERISTICS OF CARBON NANOTUBES AND THEIR APPLICATIONS IN SENSORS AND DEVICES A. Vaseashta, C. Shaffer, M. Collins, A. Mwuara Dept of Physics, Marshall University, Huntington, WV V. Pokropivny Institute for Materials Sciences of NASU, Kiev, Ukraine. D. Dimova-Malinovska Bulgarian Academy of Sciences, Sofia, Bulgaria. The dimensionality of a system has profound influence on its physical behavior. With advances in technology over the past few decades, it has become possible to fabricate and study reduced-dimensional systems, such as carbon nanotubes (CNTs). Carbon nanotubes are especially promising candidate for cold cathode field emitter because of their electrical properties, high aspect ratio, and small radius of curvature at the tips. Electron emission from the carbon nanotubes was investigated. Based upon the field emission investigation of carbon nanotubes, several prototype devices have been suggested that operate with low swing voltages with sufficient high current densities. Characteristics that allow improved current stability and long lifetime operation for electrical and opto-electronics devices are presented. The aim of this brief overview is to illustrate the useful characteristics of carbon nanotubes and its possible application.
Vaseashta, Ashok
RESULTS FROM THE U.S. DOE 2006 SAVE ENERGY NOW ASSESSMENT INITIATIVE: DOE's Partnership with U.S. Industry to Reduce Energy Consumption, Energy Costs, and Carbon Dioxide Emissions
In the wake of Hurricane Katrina and other severe storms in 2005, natural gas supplies were restricted, prices rose, and industry sought ways to reduce its natural gas use and costs. In October 2005, U.S. Department of Energy (DOE) Energy Secretary Bodman launched his Easy Ways to Save Energy campaign with a promise to provide energy assessments to 200 of
Anthony L Wright; Michaela A Martin; Bob Gemmer; Paul Scheihing; James Quinn
A review on black carbon emissions, worldwide and in China.
Black carbon (BC) produced from open burning (OB) and controlled combustion (CC) is a range of carbonaceous products of incomplete combustion of biomass and fossil fuel, and is deemed as one of the major contributors to impact global environment and human health. BC has a strong relationship with POPs, in waste combustion, BC promotes the formation of POPs, and then the transport of POPs in the environment is highly influenced by BC. However less is known about BC formation, measurement and emissions estimation especially in developing countries such as China. Different forms of BC are produced both in CC and OB. BC emission characteristics and combustion parameters which determine BC emissions from CC and OB are discussed. Recent studies showed a lack of common methodology and the resulting data for describing the mechanisms related to BC formation during combustion processes. Because BC is a continuum carbonaceous combustion product, different sampling and measuring methods are used for measuring their emissions with great quantitative uncertainty. We discuss the commonly used BC sampling and measuring methods along with the causes for uncertainty and measures to minimizing the uncertainty. Then, we discuss the estimations of BC emission factors and emission inventory for CC and OB sources. The total emissions of BC from CC and OB in China are also estimated and compared with previous BC emission inventories in this review and we find the inventories tend to be overestimated. As China becomes the largest contributor to global BC emissions, studies for characterizing BC emissions from OB and CC sources are absent in China. Finally, we comment on the current state of BC emission research and identify major deficiencies that need to overcome. Moreover, the advancement in research tools, measuring technique in particular, as discussed in this review is critical for researchers in developing countries to improve their capability to study BC emissions for addressing the growing climate change and public health concerns. PMID:24875874
Ni, Mingjiang; Huang, Jianxin; Lu, Shengyong; Li, Xiaodong; Yan, Jianhua; Cen, Kefa
High resolution of black carbon and organic carbon emissions in the Pearl River Delta region, China.
A high-resolution regional black carbon (BC) and organic carbon (OC) emission inventory for the year 2009 was developed for the Pearl River Delta (PRD) region, China, based on the collected activity data and the latest emission factors. PM(2.5), BC and OC emissions were estimated to be 303 kt, 39 kt and 31 kt, respectively. Industrial processes were major contributing sources to PM(2.5) emissions. BC emissions were mainly from mobile sources, accounting for 65.0%, while 34.1% of OC emissions were from residential combustion. The primary OC/BC ratios for individual cities in the PRD region were dependent on the levels of economic development due to differences in source characteristics, with high ratios in the less developed cities and low ratios in the central and southern developed areas. The preliminary temporal profiles were established, showing the highest OC emissions in winter and relatively constant BC emissions throughout the year. The emissions were spatially allocated into grid cells with a resolution of 3 km Î 3 km. Large amounts of BC emissions were distributed over the central-southern PRD city clusters, while OC emissions exhibited a relatively even spatial distribution due to the significant biomass burning emissions from the outlying area of the PRD region. Uncertainties in carbonaceous aerosol emissions were usually higher than in other primary pollutants like SO(2), NO(x), and PM(10). One of the key uncertainty sources was the emission factor, due to the absence of direct measurements of BC and OC emission rates. PMID:22995707
Zheng, Junyu; He, Min; Shen, Xingling; Yin, Shasha; Yuan, Zibing
Reducing the environmental impact of trials: a comparison of the carbon footprint of the CRASH-1 and CRASH-2 clinical trials
Background All sectors of the economy, including the health research sector, must reduce their carbon emissions. The UK National Institute for Health Research has recently prepared guidelines on how to minimize the carbon footprint of research. We compare the carbon emissions from two international clinical trials in order to identify where emissions reductions can be made. Methods We conducted a carbon audit of two clinical trials (the CRASH-1 and CRASH-2 trials), quantifying the carbon dioxide emissions produced over a one-year audit period. Carbon emissions arising from the coordination centre, freight delivery, trial-related travel and commuting were calculated and compared. Results The total emissions in carbon dioxide equivalents during the one-year audit period were 181.3 tonnes for CRASH-1 and 108.2 tonnes for CRASH-2. In total, CRASH-1 emitted 924.6 tonnes of carbon dioxide equivalents compared with 508.5 tonnes for CRASH-2. The CRASH-1 trial recruited 10,008 patients over 5.1 years, corresponding to 92 kg of carbon dioxide per randomized patient. The CRASH-2 trial recruited 20,211 patients over 4.7 years, corresponding to 25 kg of carbon dioxide per randomized patient. The largest contributor to emissions in CRASH-1 was freight delivery of trial materials (86.0 tonnes, 48% of total emissions), whereas the largest contributor in CRASH-2 was energy use by the trial coordination centre (54.6 tonnes, 30% of total emissions). Conclusions Faster patient recruitment in the CRASH-2 trial largely accounted for its greatly increased carbon efficiency in terms of emissions per randomized patient. Lighter trial materials and web-based data entry also contributed to the overall lower carbon emissions in CRASH-2 as compared to CRASH-1. Trial Registration Numbers CRASH-1: ISRCTN74459797 CRASH-2: ISRCTN86750102
Black carbon emissions in gasoline exhaust and a reduction alternative with a gasoline particulate filter.
Black carbon (BC) mass and solid particle number emissions were obtained from two pairs of gasoline direct injection (GDI) vehicles and port fuel injection (PFI) vehicles over the U.S. Federal Test Procedure 75 (FTP-75) and US06 Supplemental Federal Test Procedure (US06) drive cycles on gasoline and 10% by volume blended ethanol (E10). BC solid particles were emitted mostly during cold-start from all GDI and PFI vehicles. The reduction in ambient temperature had significant impacts on BC mass and solid particle number emissions, but larger impacts were observed on the PFI vehicles than the GDI vehicles. Over the FTP-75 phase 1 (cold-start) drive cycle, the BC mass emissions from the two GDI vehicles at 0 ░F (-18 ░C) varied from 57 to 143 mg/mi, which was higher than the emissions at 72 ░F (22 ░C; 12-29 mg/mi) by a factor of 5. For the two PFI vehicles, the BC mass emissions over the FTP-75 phase 1 drive cycle at 0 ░F varied from 111 to 162 mg/mi, higher by a factor of 44-72 when compared to the BC emissions of 2-4 mg/mi at 72 ░F. The use of a gasoline particulate filter (GPF) reduced BC emissions from the selected GDI vehicle by 73-88% at various ambient temperatures over the FTP-75 phase 1 drive cycle. The ambient temperature had less of an impact on particle emissions for a warmed-up engine. Over the US06 drive cycle, the GPF reduced BC mass emissions from the GDI vehicle by 59-80% at various temperatures. E10 had limited impact on BC emissions from the selected GDI and PFI vehicles during hot-starts. E10 was found to reduce BC emissions from the GDI vehicle by 15% at standard temperature and by 75% at 19 ░F (-7 ░C). PMID:24758145
Chan, Tak W; Meloche, Eric; Kubsh, Joseph; Brezny, Rasto
Grape marc reduces methane emissions when fed to dairy cows.
Grape marc (the skins, seeds, stalk, and stems remaining after grapes have been pressed to make wine) is currently a by-product used as a feed supplement by the dairy and beef industries. Grape marc contains condensed tannins and has high concentrations of crude fat; both these substances can reduce enteric methane (CH4) production when fed to ruminants. This experiment examined the effects of dietary supplementation with either dried, pelleted grape marc or ensiled grape marc on yield and composition of milk, enteric CH4 emissions, and ruminal microbiota in dairy cows. Thirty-two Holstein dairy cows in late lactation were offered 1 of 3 diets: a control (CON) diet; a diet containing dried, pelleted grape marc (DGM); and a diet containing ensiled grape marc (EGM). The diet offered to cows in the CON group contained 14.0kg of alfalfa hay dry matter (DM)/d and 4.3kg of concentrate mix DM/d. Diets offered to cows in the DGM and EGM groups contained 9.0kg of alfalfa hay DM/d, 4.3kg of concentrate mix DM/d, and 5.0kg of dried or ensiled grape marc DM/d, respectively. These diets were offered individually to cows for 18d. Individual cow feed intake and milk yield were measured daily and milk composition measured on 4d/wk. Individual cow CH4 emissions were measured by the SF6 tracer technique on 2d at the end of the experiment. Ruminal bacterial, archaeal, fungal, and protozoan communities were quantified on the last day of the experiment. Cows offered the CON, DGM, and EGM diets, ate 95, 98, and 96%, respectively, of the DM offered. The mean milk yield of cows fed the EGM diet was 12.8kg/cow per day and was less than that of cows fed either the CON diet (14.6kg/cow per day) or the DGM diet (15.4kg/cow per day). Feeding DGM and EGM diets was associated with decreased milk fat yields, lower concentrations of saturated fatty acids, and enhanced concentrations of mono- and polyunsaturated fatty acids, in particular cis-9,trans-11 linoleic acid. The mean CH4 emissions were 470, 375, and 389g of CH4/cow per day for cows fed the CON, DGM, and EGM diets, respectively. Methane yields were 26.1, 20.2, and 21.5g of CH4/kg of DMI for cows fed the CON, DGM, and EGM diets, respectively. The ruminal bacterial and archaeal communities were altered by dietary supplementation with grape marc, but ruminal fungal and protozoan communities were not. Decreases of approximately 20% in CH4 emissions and CH4 yield indicate that feeding DGM and EGM could play a role in CH4 abatement. PMID:24952778
Moate, P J; Williams, S R O; Torok, V A; Hannah, M C; Ribaux, B E; Tavendale, M H; Eckard, R J; Jacobs, J L; Auldist, M J; Wales, W J
Field emission of electrons from carbon nanotubes: Emission mechanisms, current stability, and the current saturation effect
NASA Astrophysics Data System (ADS)
Single-walled nanotubes (SWNTs) are emerging as suitable electron sources for field emission devices due to several interesting properties. These include field emission at anomalously low applied voltages, stable emission in non-ideal vacuum environments, and intrinsic saturation of emission current. This dissertation determines the underlying mechanisms responsible for these three properties and characterizes the field emission behavior of clean SWNTs. The field emission behavior of SWNTs has been investigated over a wide range temperatures and electric fields. Utilizing field emission microscopy, electron energy distribution (EED) measurements, and current-voltage-temperature measurements, several behavioral regimes of field emission have been identified. In the first regime, adsorbate surface states dominate the field emission behavior at room temperature, even under ultrahigh vacuum conditions. These adsorbate states correlate with the presence of water. They enhance the tunneling probability, thus explaining field emission at anomalously low voltages. The second behavioral regime, that of clean SWNTs, is obtained by desorbing the adsorbates above 900 K. Field emission microscope images of clean SWNTs show fine structure related to electronic states of the nanotube caps. Current-temperature and EED measurements indicate that SWNTs emit electrons through surface states in the caps. At high fields and temperatures where current from an individual SWNT exceeds ś2 muA, rings form around field emission microscope patterns and the patterns spin. Simultaneous pattern rearrangement and current degradation indicate the removal of carbon atoms at the nanotube end-cap. SWNTs were found to exhibit long-term field emission stability in environments that destroy metal emitters in hours. Protrusion growth and current runaway were not observed, but nanotubes do show susceptibility to oxidation damage. Environmental stability results from geometry, strong carbon bonding, and the lack of protrusion growth. Carbon nanotubes exhibit intrinsic current saturation that was found result from adsorbates states. Current saturation occurs at emission currents above 100 nA per nanotube and coincides with rapid current fluctuations and distinctive changes in the field emission microscope patterns. Current saturation results from the displacement of adsorbates from configurations of tunneling enhancement as electric field and current are increased. At high fields, adsorbates can be completely removed from the nanotube.
Dean, Kenneth Andrew
Shade trees reduce building energy use and CO2 emissions from power plants
Urban shade trees offer significant benefits in reducing building air-conditioning demand and improving urban air quality by reducing smog. The savings associated with these benefits vary by climate region and can be up to $200 per tree. The cost of planting trees and maintaining them can vary from $10 to $500 per tree. Tree-planting programs can be designed to have lower costs so that they offer potential savings to communities that plant trees. Our calculations suggest that urban trees play a major role in sequestering C02 and thereby delay global warming. We estimate that a tree planted in Los Angeles avoids the combustion of 18 kg of carbon annually, even though it sequesters only 4.5-11 kg (as it would if growing in a forest). In this sense, one shade tree in Los Angeles is equivalent to three to five forest trees. In a recent analysis for Baton Rouge, Sacramento, and Salt Lake City, we estimated that planting an average of four shade trees per house (each with a top view cross section of 50 m2) would lead to an annual reduction in carbon emissions from power plants of 16,000, 41,000, and 9000 t, respectively (the per-tree reduction in carbon emissions is about 10-11 kg per year). These reductions only account for the direct reduction in the net cooling- and heating-energy use of buildings. Once the impact of the community cooling is included, these savings are increased by at least 25 percent.
Akbari, H.
Associations of individual, household and environmental characteristics with carbon dioxide emissions from motorised passenger travel
Carbon dioxide (CO2) emissions from motorised travel are hypothesised to be associated with individual, household, spatial and other environmental factors. Little robust evidence exists on who contributes most (and least) to travel CO2 and, in particular, the factors influencing commuting, business, shopping and social travel CO2. This paper examines whether and how demographic, socio-economic and other personal and environmental characteristics are associated with land-based passenger transport and associated CO2 emissions. Primary data were collected from 3474 adults using a newly developed survey instrument in the iConnect study in the UK. The participants reported their past-week travel activity and vehicle characteristics from which CO2 emissions were derived using an adapted travel emissions profiling method. Multivariable linear and logistic regression analyses were used to examine what characteristics predicted higher CO2 emissions. CO2 emissions from motorised travel were distributed highly unequally, with the top fifth of participants producing more than two fifth of emissions. Car travel dominated overall CO2 emissions, making up 90% of the total. The strongest independent predictors of CO2 emissions were owning at least one car, being in full-time employment and having a home-work distance of more than 10ákm. Income, education and tenure were also strong univariable predictors of CO2 emissions, but seemed to be further back on the causal pathway than having a car. Male gender, late-middle age, living in a rural area and having access to a bicycle also showed significant but weaker associations with emissions production. The findings may help inform the development of climate change mitigation policies for the transport sector. Targeting individuals and households with high car ownership, focussing on providing viable alternatives to commuting by car, and supporting planning and other policies that reduce commuting distances may provide an equitable and efficient approach to meeting carbon mitigation targets.
Brand, Christian; Goodman, Anna; Rutter, Harry; Song, Yena; Ogilvie, David
Nitrous oxide emission by denitrifying phosphorus removal culture using polyhydroxyalkanoates as carbon source.
Nitrous oxide (N2O) emission has been reported to be enhanced during denitrification when internally-stored compounds are used as carbon sources. However, negligible N2O emissions have been detected in the few studies where polyhydroxyalkanoates (PHA) were specifically used. This study investigated and compared the potential enhancement of N2O production, based on utilization of an internally-stored polymer and external carbon (acetate) by a denitrifying phosphorus removal culture. Results indicated that at relatively low chemical oxygen demand-to-nitrogen (COD/N) ratios, more nitrite was reduced to N2O in the presence of an external carbon source as compared to an internal carbon source (PHA). At relatively higher COD/N ratios, similar N2O reduction rates were obtained in all cases regardless of the type of carbon source available. N2O reduction rates were, however, generally higher in the presence of an internal carbon source. Results from the study imply that when the presence of an external carbon source is not sufficient to support denitrification, it is likely competitively utilized by different metabolic pathways of denitrifying polyphosphate accumulating organisms (DPAOs) and other ordinary denitrifiers. This study also reveals that the consumption of PHA is potentially the rate-limiting step for N2O reduction during denitrification. PMID:23520869
Zhou, Yan; Lim, Melvin; Harjono, Soekendro; Ng, Wun Jern
Thermionic Emission of Single-Wall Carbon Nanotubes Measured
NASA Technical Reports Server (NTRS)
Researchers at the NASA Glenn Research Center, in collaboration with the Rochester Institute of Technology, have investigated the thermionic properties of high-purity, single-wall carbon nanotubes (SWNTs) for use as electron-emitting electrodes. Carbon nanotubes are a recently discovered material made from carbon atoms bonded into nanometer-scale hollow tubes. Such nanotubes have remarkable properties. An extremely high aspect ratio, as well as unique mechanical and electronic properties, make single-wall nanotubes ideal for use in a vast array of applications. Carbon nanotubes typically have diameters on the order of 1 to 2 nm. As a result, the ends have a small radius of curvature. It is these characteristics, therefore, that indicate they might be excellent potential candidates for both thermionic and field emission.
Landis, Geoffrey A.; Krainsky, Isay L.; Bailey, Sheila G.; Elich, Jeffrey M.; Landi, Brian J.; Gennett, Thomas; Raffaelle, Ryne P.
C&C - Contraction and Convergence of Carbon Emissions: The Economic Implications of International Emissions Trading
In the context of climate protection policy it has been suggested that global CO2 emissions should be reduced significantly (contraction) and that per capita emissions should gradually be equalized across countries (convergence). This paper uses a dynamic multi-region computable general equilibrium model of the world economy to assess the economics of \\
Christoph B÷hringer; Heinz Welsch
Reducing Open Cell Landfill Methane Emissions with a Bioactive Alternative Daily
Methane and carbon dioxide are formed in landfills as wastes degrade. Molecule-for-molecule, methane is about 20 times more potent than carbon dioxide at trapping heat in the earth's atmosphere, and thus, it is the methane emissions from landfills that are scrutinized. For example, if emissions composed of 60% methane and 40% carbon dioxide were changed to a mix that was 40% methane and 60% carbon dioxide, a 30% reduction in the landfill's global warming potential would result. A 10% methane, 90% carbon dioxide ratio will result in a 75% reduction in global warming potential compared to the baseline. Gas collection from a closed landfill can reduce emissions, and it is sometimes combined with a biocover, an engineered system where methane oxidizing bacteria living in a medium such as compost, convert landfill methane to carbon dioxide and water. Although methane oxidizing bacteria merely convert one greenhouse gas (methane) to another (carbon dioxide), this conversion can offer significant reductions in the overall greenhouse gas contribution, or global warming potential, associated with the landfill. What has not been addressed to date is the fact that methane can also escape from a landfill when the active cell is being filled with waste. Federal regulations require that newly deposited solid waste to be covered daily with a 6 in layer of soil or an alternative daily cover (ADC), such as a canvas tarp. The aim of this study was to assess the feasibility of immobilizing methane oxidizing bacteria into a tarp-like matrix that could be used for alternative daily cover at open landfill cells to prevent methane emissions. A unique method of isolating methanotrophs from landfill cover soil was used to create a liquid culture of mixed methanotrophs. A variety of prospective immobilization techniques were used to affix the bacteria in a tarp-like matrix. Both gel encapsulation of methanotrophs and gels with liquid cores containing methanotrophs were readily made but prone to rapid desiccation. Bacterial adsorption onto foam padding, natural sponge, and geotextile was successful. The most important factor for success appeared to be water holding capacity. Prototype biotarps made with geotextiles plus adsorbed methane oxidizing bacteria were tested for their responses to temperature, intermittent starvation, and washing (to simulate rainfall). The prototypes were mesophilic, and methane oxidation activity remained strong after one cycle of starvation but then declined with repeated cycles. Many of the cells detached with vigorous washing, but at least 30% appeared resistant to sloughing. While laboratory landfill simulations showed that four-layer composite biotarps made with two different types of geotextile could remove up to 50% of influent methane introduced at a flux rate of 22 g m{sup -2} d{sup -1}, field experiments did not yield high activity levels. Tests revealed that there were high hour-to-hour flux variations in the field, which, together with frequent rainfall events, confounded the field testing. Overall, the findings suggest that a methanotroph embedded biotarp appears to be a feasible strategy to mitigate methane emission from landfill cells, although the performance of field-tested biotarps was not robust here. Tarps will likely be best suited for spring and summer use, although the methane oxidizer population may be able to shift and adapt to lower temperatures. The starvation cycling of the tarp may require the capacity for intermittent reinoculation of the cells, although it is also possible that a subpopulation will adapt to the cycling and become dominant. Rainfall is not expected to be a major factor, because a baseline biofilm will be present to repopulate the tarp. If strong performance can be achieved and documented, the biotarp concept could be extended to include interception of other compounds beyond methane, such as volatile aromatic hydrocarbons and chlorinated solvents.
Helene Hilger; James Oliver; Jean Bogner; David Jones
A technology-based global inventory of black and organic carbon emissions from combustion
We present a global tabulation of black carbon (BC) and primary organic carbon (OC) particles emitted from combustion. We include emissions from fossil fuels, biofuels, open biomass burning, and burning of urban waste. Previous ôbottom-upö inventories of black and organic carbon have assigned emission factors on the basis of fuel type and economic sector alone. Because emission rates are highly
Tami C. Bond; David G. Streets; Kristen F. Yarber; Sibyl M. Nelson; Jung-Hun Woo; Zbigniew Klimont
Measurement and communication of greenhouse gas emissions from U.S. food consumption via carbon calculators
Food consumption may account for upwards of 15% of U.S. per capita greenhouse gas emissions. Online carbon calculators can help consumers prioritize among dietary behaviors to minimize personal ôcarbon footprints,ö leveraging against emissions-intensive industry practices. We reviewed the fitness of selected carbon calculators for measuring and communicating indirect GHG emissions from food consumption. Calculators were evaluated based on the scope
Brent Kim; Roni Neff
Carbon dioxide and methane emissions from the Yukon River system
NASA Astrophysics Data System (ADS)
Carbon dioxide (CO2) and methane (CH4) emissions are important, but poorly quantified, components of riverine carbon (C) budgets. This is largely because the data needed for gas flux calculations are sparse and are spatially and temporally variable. Additionally, the importance of C gas emissions relative to lateral C exports is not well known because gaseous and aqueous fluxes are not commonly measured on the same rivers. We couple measurements of aqueous CO2 and CH4 partial pressures (pCO2, pCH4) and flux across the water-air interface with gas transfer models to calculate subbasin distributions of gas flux density. We then combine those flux densities with remote and direct observations of stream and river water surface area and ice duration, to calculate C gas emissions from flowing waters throughout the Yukon River basin. CO2 emissions were 7.68 Tg C yr-1 (95% CI: 5.84 -10.46), averaging 750 g C m-2 yr-1 normalized to water surface area, and 9.0 g C m-2 yr-1 normalized to river basin area. River CH4 emissions totaled 55 Gg C yr-1 or 0.7% of the total mass of C emitted as CO2 plus CH4 and ś6.4% of their combined radiative forcing. When combined with lateral inorganic plus organic C exports to below head of tide, C gas emissions comprised 50% of total C exported by the Yukon River and its tributaries. River CO2 and CH4 derive from multiple sources, including groundwater, surface water runoff, carbonate equilibrium reactions, and benthic and water column microbial processing of organic C. The exact role of each of these processes is not yet quantified in the overall river C budget.
Striegl, Robert G.; Dornblaser, M. M.; McDonald, C. P.; Rover, J. R.; Stets, E. G.
Trend in global black carbon emissions from 1960 to 2007.
Black carbon (BC) plays an important role in both climate change and health impact. Still, BC emissions as well as the historical trends are associated with high uncertainties in existing inventories. In the present study, global BC emissions from 1960 to 2007 were estimated for 64 sources, by using recompiled fuel consumption and emission factor data sets. Annual BC emissions had increased from 5.3 (3.4-8.5 as an interquartile range) to 9.1 (5.6-14.4) teragrams during this period. Our estimations are 11-16% higher than those in previous inventories. Over the period, we found that the BC emission intensity, defined as the amount of BC emitted per unit of energy production, had decreased for all the regions, especially China and India. Improvements in combustion technology and changes in fuel composition had led to an increase in energy use efficiency, and subsequently a decline of BC emission intensities in power plants, the residential sector, and transportation. On the other hand, the BC emission intensities had increased in the industrial and agricultural sectors, mainly due to an expansion of low-efficiency industry (coke and brick production) in developing countries and to an increasing usage of diesel in agriculture in developed countries. PMID:24825392
Wang, Rong; Tao, Shu; Shen, Huizhong; Huang, Ye; Chen, Han; Balkanski, Yves; Boucher, Olivier; Ciais, Philippe; Shen, Guofeng; Li, Wei; Zhang, Yanyan; Chen, Yuanchen; Lin, Nan; Su, Shu; Li, Bengang; Liu, Junfeng; Liu, Wenxin
Application of Pollution Prevention Techniques to Reduce Indoor Air Emissions from Engineered Wood Products.
National Technical Information Service (NTIS)
The report gives results of an investigation of pollution prevention options to reduce indoor emissions from a type of finished engineered wood. Emissions were screened from four types of finished engineered wood: oak-veneered particleboard coated and cur...
C. M. Brockmann L. S. Sheldon D. A. Whitaker J. N. Baskir
Energy, Carbon-emission and Financial Savings from Thermostat Control
Among the easiest approaches to energy, and cost, savings for most people is the adjustment of thermostats to save energy. Here we estimate savings of energy, carbon, and money in the United States of America (USA) that would result from adjusting thermostats in residential and commercial buildings by about half a degree Celsius downward during the heating season and upward during the cooling season. To obtain as small a unit as possible, and therefore the least likely to be noticeable by most people, we selected an adjustment of one degree Fahrenheit (0.56 degree Celsius) which is the gradation used almost exclusively on thermostats in the USA and is the smallest unit of temperature that has been used historically. Heating and/or cooling of interior building space for personal comfort is sometimes referred to as space conditioning, a term we will use for convenience throughout this work without consideration of humidity. Thermostat adjustment, as we use the term here, applies to thermostats that control the indoor temperature, and not to other thermostats such as those on water heaters. We track emissions of carbon only, rather than of carbon dioxide, because carbon atoms change atomic partners as they move through the carbon cycle, from atmosphere to biosphere or ocean and, on longer time scales, through the rock cycle. To convert a mass of carbon to an equivalent mass of carbon dioxide (thereby including the mass of the 2 oxygen atoms in each molecule) simply multiply by 3.67.
Blasing, T J [ORNL; Schroeder, Dana [University of Georgia, Athens, GA
Global carbon dioxide emission to the atmosphere by volcanoes
Global emission of carbon dioxide by subaerial volcanoes is calculated, using CO{sub 2}/SO{sub 2} from volcanic gas analyses and SO{sub 2} flux, to be 34 {plus minus} 24 {times} 10{sup 12} g CO{sub 2}/yr from passive degassing and 31 {plus minus} 22 {times} 10{sup 12} g CO{sub 2}/yr from eruptions. Volcanic CO{sub 2} presently represents only 0.22% of anthropogenic emissions but may have contributed to significant greenhouse' effects at times in Earth history. Models of climate response to CO{sub 2} increases may be tested against geological data.
Williams, S.N.; Schaefer, S.J. (Arizona State Univ., Tempe (United States)); Calvache V., M.L. (Arizona State Univ., Tempe (United States) Observatorio Vulcanologico de Colombia, Pasto (Colombia)); Lopez, D. (Univ. of British Columbia, Vancouver (Canada))
Climate warming feedback from mountain birch forest expansion: reduced albedo dominates carbon uptake.
Expanding high-elevation and high-latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6á░C increase in summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100ám lower than its climatic potential due to land-use history. In the future scenarios, forest cover increased from 12% to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high-latitude and high-elevation expanding forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts. PMID:24343906
de Wit, Heleen A; Bryn, Anders; Hofgaard, Annika; Karstensen, Jonas; Kvalevňg, Maria M; Peters, Glen P
2002 Monthly Carbon Dioxide Emissions from Mexico at a 10x10k Spatial Resolution
NASA Astrophysics Data System (ADS)
The contribution of fossil fuel CO2 emissions to the total measured amount of CO2 in the Earthĺs atmosphere remains an important component of carbon cycle science, particularly as efforts to understand the net exchange of carbon at the surface move to smaller scales. In order to reduce the uncertainty of this flux, researchers led by Purdue University have built a high-resolution fossil fuel CO2 flux inventory for the United States, called ôVulcanö. The Vulcan inventory quantifies emissions for the United States at 10km resolution every hour for the year 2002 and can be seen as a key component of a national assessment and verification system for greenhouse gas emissions and emissions mitigation. As part of the North American Carbon Project, the 2002 carbon dioxide emissions from Mexico are presented at the monthly temporal and municipality spatial scale. Mexico is of particular importance because of the scientific integration under the North American Carbon Program. Furthermore, Mexico has seen a notable growth in its population as well as migration toward urban centers and increasing energy requirements due in part to industrial intensification. The native resolution of the emissions is geolocated (lat/lon) for point sources, such as power plants, airports, and large industry. The emissions are estimated at the municipality level for residential and commercial sources, and allocated to roads for the mobile transport sector. Data sources include the National Emissions Inventory (NEI), Commission for Environmental Cooperation (CEC), and Carbon Monitoring for Action (CARMA). CO2 emissions are calculated from the 1999 NEI data by converting CO emissions using sector and process-dependent emission factors, and is scaled up to 2002 using statistics obtained from the Carbon Dioxide Information Analysis Center CDIAC. CEC and CARMA data, which encompass power plant emissions, are already in units of CO2. Emissions are regridded to 10x10k and 0.1x0.1 deg grids to enable atmospheric CO2 transport modeling. All economic sectors are analyzed, including power plants, commercial, residential, industrial, on-road, and non-road. Municipality and regional scale analysis is presented to explore the differences in economic and industrial development and need. Specific centers of high emissions are highlighted and analyzed in order to put into context the development and growth of certain economic sectors. The annualized emissions are compared to estimates by the International Energy Agency and found to be very similar although some discrepancies are expected due to the different methods of obtaining results. Vulcan reports process-based emissions while IEA reports fuel sales. The Vulcan output is also disaggregated by fuel type and comparisons with IEA are presented across economic sectors. A monthly product based on monthly sales is also presented. Sales by major fuel types (oil, natural gas, coal) are obtained from EIA data and those results shape the monthly cycle. These results are compared to a similar national studies, and similarities and differences are analyzed and discussed.
Mendoza, D. L.; Gurney, K. R.; Geethakumar, S.; Zhou, Y.; Sahni, N.
Just Say No to Carbon Emissions (LBNL Science at the Theater)
Learn about three efforts our grandchildren may thank us for: cheap solar energy, bringing energy efficiency to China, and learning how to store carbon deep underground. Can solar energy be dirt cheap? We're all potentially billionaires when it comes to solar energy. The trick is learning how to convert sunlight to electricity using cheap and plentiful materials. Ramamoorthy Ramesh, an innovative materials scientist at Berkeley Lab, will discuss how he and other researchers are working to make photovoltaic cells using the most abundant elements in the Earth's crust -- materials that are literally as common as dirt. Energy efficiency in China: Nan Zhou is a researcher with Berkeley Labs China Energy Group. She will speak about Chinas energy use and the policies that have been implemented to increase energy efficiency and reduce CO2 emission growth. Her work focuses on building China's capacity to evaluate, adopt and implement low-carbon development strategies. Zhou has an architecture degree from China, and a Master and Ph.D. in Engineering from Japan. Understanding geologic carbon sequestration: Even with continued growth of renewable energy sources such as wind and solar, fossil fuels will likely remain cheap and plentiful for decades to come. Geologist Curt Oldenburg, who heads Berkeley Lab's Geologic Carbon Sequestration Program, will discuss a strategy to reduce carbon emissions from coal and natural gas. It involves pumping compressed CO2 captured from large stationary sources into underground rock formations that can store it for geological time scales.
Ramesh, Ramamoorthy; Zhou, Nan; Oldenburg, Curt
Reducing the risk of accidental death due to vehicle-related carbon monoxide poisoning.
Emissions of carbon monoxide (CO) from motor vehicles cause several hundred accidental fatal poisonings annually in the United States. The circumstances that could lead to fatal poisonings in residential settings with motor vehicles as the source of CO were explored. The risk of death in a garage (volume = 90 m3) and a single-family dwelling (400 m3) was evaluated using a Monte Carlo simulation with varying CO emission rates and ventilation rates. Information on emission rates was obtained from a survey of motor vehicle exhaust gas composition under warm idle conditions in California, and information on ventilation rates was obtained from a summary of published measurements in the U.S. housing stock. The risk of death ranged from 16 to 21% for a 3-hr exposure in a garage to 0% for a 1-hr exposure in a house. Older vehicles were associated with a disproportionately high risk of death. Removing all pre-1975 vehicles from the fleet would reduce the risk of death by one-fourth to two-thirds, depending on the exposure scenario. Significant efforts have been made to control CO emissions from motor vehicles with the goal of reducing CO concentrations in outdoor air. Substantial public health benefit could also be obtained if vehicle control measures were designed to take account of acute CO poisonings explicitly. PMID:9798430
Marr, L C; Morrison, G C; Nazaroff, W W; Harley, R A
A guide to potential soil carbon sequestration; land-use management for mitigation of greenhouse gas emissions
Terrestrial carbon sequestration has a potential role in reducing the recent increase in atmospheric carbon dioxide (CO2) that is, in part, contributing to global warming. Because the most stable long-term surface reservoir for carbon is the soil, changes in agriculture and forestry can potentially reduce atmospheric CO2 through increased soil-carbon storage. If local governments and regional planning agencies are to effect changes in land-use management that could mitigate the impacts of increased greenhouse gas (GHG) emissions, it is essential to know how carbon is cycled and distributed on the landscape. Only then can a cost/benefit analysis be applied to carbon sequestration as a potential land-use management tool for mitigation of GHG emissions. For the past several years, the U.S. Geological Survey (USGS) has been researching the role of terrestrial carbon in the global carbon cycle. Data from these investigations now allow the USGS to begin to (1) 'map' carbon at national, regional, and local scales; (2) calculate present carbon storage at land surface; and (3) identify those areas having the greatest potential to sequester carbon.
Markewich, H. W.; Buell, G. R.
Economic development, poverty reduction and carbon emissions in India
This paper analyses carbon dioxide (CO2) emissions from energy consumption using an input-output (I-O) model, for different sectors of the Indian economy in 1990. Alternative scenarios are developed for 2005. The I-O model considers structural changes in aggregate consumption behaviour and sectoral composition of output between 1990 and 2005. Alternative energy efficiency programmes are compared for their potential CO2 reduction
N. S. Murthy; Manoj Panda; Jyoti Parikh
Energy Use and Carbon Emissions: Some International Comparisons
Presents energy use and carbon emissions patterns in a world context. The report contrasts trends in economically developed and developing areas of the world since 1970, presents a disaggregated view of the "Group of Seven" (G7) key industrialized countries (Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States) and examines sectoral energy use patterns within each of the G7 countries.
Information Center
Growth rates of carbon dioxide emission in India
SummaryááEstimates have been made of the carbon dioxide (CO2) emission into the atmosphere through the combustion of non-fossil and fossil fuels in India for the period 1950ľ1982. Results show that 6.5 Î 1015 g C has been added to the earth's atmosphere. Of this, the individual contributions have been 69.2% by fire-wood, 23.7% by coal, 6.2% by petroleum products, 0.3%
L. S. Hingane; Bh. V. Ramana Murty
Heavy-ion-induced electron emission from thin carbon foils
We have measured heavy-ion-induced (5<=Zp<=26 0.3
A. Clouvas; A. Katsanos; B. Farizon-Mazuy; M. Farizon; M. J. Gaillard
Nitrous oxide emissions from intensively managed agroecosystems: the role of carbon inputs (Invited)
NASA Astrophysics Data System (ADS)
In agroecosystems, many reports demonstrate a positive relationship between N2O emissions and N fertilizer inputs. This relationship has been incorporated into the IPCC model estimate of N2O emissions and implies that inorganic N availability limits N2O emissions. However, evidence indicates that denitrification accounts for most N2O emissions from agroecosystems and N2O production from denitrification requires reduced C in addition to oxidized N. Using two experiments and meta-analysis we highlight the potential importance of reduced carbon availability for NČ2O emissions from agroecosystems. Experiments were conducted in maize-based cropping systems, restored prairies and perennial vegetation buffers in Iowa, USA. These systems have high soil organic C (SOC) concentrations. In the first experiment, a cover crop preceding maize increased N2O emissions despite immobilizing large amounts of NO3. Laboratory incubations of these soils demonstrated that glucose, but not NO3, increased N2O emissions. Because the cover crop had no detectable effect on total or potentially mineralizable SOC, these results indicate that the relatively small cover crop C input increased N2O emissions from this system. In a second experiment that compared land uses (maize, restored prairies, and perennial vegetation buffers) with significant differences in total SOC (2.3, 2.8 and 3.0% C, respectively), 15N tracer application demonstrated the increase in SOC across land uses was associated with more complete denitrification to N2 rather than an increase in N immobilization or N2O emissions. Results from these experiments suggest a complex interaction between NO3 and potentially mineralizable C affects denitrification emissions of N2O and particularly the N2O/(N2+N2O) ratio: although a small plant-based C input increased N2O emissions in a NO3-rich soil, a larger long-term increase in total SOC reduced N2O emissions by decreasing the N2O/(N2+N2O) ratio. Consistent with our cover crop experiment, a meta-analysis revealed that 60% of published reports find that cover crops increase N2O emissions while 40% of published reports find that cover crops decrease N2O emissions. As a wide variety of options are considered for mitigation of N2O emissions from agroecosystems, both C and N availability must be considered.
Castellano, M. J.; Iqbal, J.; Mitchell, D. C.; Basche, A.; Parkin, T.; Miguez, F.; Kaspar, T.
Probabilistic quantification of allowable carbon emissions for meeting multiple climate targets
NASA Astrophysics Data System (ADS)
Climate targets are designed to inform policies that would limit the magnitude and impacts of climate change caused by anthropogenic emissions of greenhouse gases and other substances. The target that is currently recognized by most world governments places a limit of two degrees Celsius on the global mean warming since preindustrial times. This would require large sustained reductions in carbon dioxide emissions during the twenty-first century and beyond. Such a global temperature target, however, is not sufficient to control many other quantities, such as transient sea level rise, ocean acidification, and net primary production on land. Here, using an Earth system model of intermediate complexity (EMIC) in an observation-informed Bayesian approach, we show that allowable carbon emissions are substantially reduced when multiple climate targets are set. We take into account uncertainties in physical and carbon cycle model parameters, radiative efficiencies, climate sensitivity, and carbon cycle feedbacks by varying nineteen key model parameters. A broad set of site-specific and gridded observational data from atmosphere, ocean, and land is used to constrain the model ensemble to realizations that are compatible with observations. Within this framework, we explore a broad range of economically feasible greenhouse gas scenarios from the integrated assessment community to determine the likelihood of meeting a combination of specific global and regional targets under various assumptions. For any given likelihood of meeting a set of such targets, the allowable cumulative emissions are greatly reduced from those inferred from the temperature target alone. Therefore, temperature targets alone are unable to comprehensively limit the risks from anthropogenic emissions.
Steinacher, M.; Joos, F.; Stocker, T. F.
Enhanced electron field emission from plasma-nitrogenated carbon nanotips
Nitrogenated carbon nanotips (NCNTPs) are synthesized by plasma-enhanced hot filament chemical vapor deposition from the hydrogen, methane, and nitrogen gas mixtures with different flow rate ratios of hydrogen to nitrogen. The morphological, structural, compositional, and electron field emission (EFE) properties of the NCNTPs were investigated by field emission scanning electron microscopy, Raman spectroscopy, x ray photoelectron spectroscopy, and EFE high-vacuum system. It is shown that the NCNTPs deposited at an intermediate flow rate ratio of hydrogen to nitrogen feature the best size/shape and pattern uniformity, the highest nanotip density, the highest nitrogen concentration, as well as the best electron field emission performance. Several factors that come into play along with the nitrogen incorporation, such as the combined effect of the plasma sputtering and etching, the transition of sp{sup 3} carbon clusters to sp{sup 2} carbon clusters, the increase of the size of the sp{sup 2} clusters, as well as the reduction of the work function, have been examined to interpret these experimental findings. Our results are highly relevant to the development of the next generation electron field emitters, flat panel displays, atomic force microscope probes, and several other advanced applications.
Wang, B. B. [College of Chemistry and Chemical Engineering, Chongqing University of Technology, 69 Hongguang Rd, Lijiatuo, Banan District, Chongqing 400054 (China); Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P. O. Box 218, Lindfield, NSW 2070 (Australia); Cheng, Q. J.; Ostrikov, K. [Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P. O. Box 218, Lindfield, NSW 2070 (Australia); Plasma Nanoscience, Complex Systems, School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia); Zhong, X. X. [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, Y. Q. [College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China); Chen, Y. A. [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China)
Enhanced electron field emission from plasma-nitrogenated carbon nanotips
NASA Astrophysics Data System (ADS)
Nitrogenated carbon nanotips (NCNTPs) are synthesized by plasma-enhanced hot filament chemical vapor deposition from the hydrogen, methane, and nitrogen gas mixtures with different flow rate ratios of hydrogen to nitrogen. The morphological, structural, compositional, and electron field emission (EFE) properties of the NCNTPs were investigated by field emission scanning electron microscopy, Raman spectroscopy, x ray photoelectron spectroscopy, and EFE high-vacuum system. It is shown that the NCNTPs deposited at an intermediate flow rate ratio of hydrogen to nitrogen feature the best size/shape and pattern uniformity, the highest nanotip density, the highest nitrogen concentration, as well as the best electron field emission performance. Several factors that come into play along with the nitrogen incorporation, such as the combined effect of the plasma sputtering and etching, the transition of sp3 carbon clusters to sp2 carbon clusters, the increase of the size of the sp2 clusters, as well as the reduction of the work function, have been examined to interpret these experimental findings. Our results are highly relevant to the development of the next generation electron field emitters, flat panel displays, atomic force microscope probes, and several other advanced applications.
Wang, B. B.; Cheng, Q. J.; Zhong, X. X.; Wang, Y. Q.; Chen, Y. A.; Ostrikov, K.
Carbon bed mercury emissions control for mixed waste treatment.
Mercury has various uses in nuclear fuel reprocessing and other nuclear processes, and so it is often present in radioactive and mixed (radioactive and hazardous) wastes. Compliance with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards can require off-gas mercury removal efficiencies up to 99.999% for thermally treating some mixed waste streams. Test programs have demonstrated this level of off-gas mercury control using fixed beds of granular sulfur-impregnated activated carbon. Other results of these tests include (1) the depth of the mercury control mass transfer zone was less than 15-30 cm for the operating conditions of these tests; (2) MERSORB carbon can sorb mercury up to 19 wt % of the carbon mass; and (3) the spent carbon retained almost all (98.3-99.99%) of the mercury during Toxicity Characteristic Leachability Procedure (TCLP) tests, but when even a small fraction of the total mercury dissolves, the spent carbon can fail the TCLP test when the spent carbon contains high mercury concentrations. PMID:21141428
Soelberg, Nick; Enneking, Joe
Early action to reduce greenhouse gas emissions before the commitment period of the Kyoto protocol: advantages and disadvantages.
Current "business as usual" projections suggest greenhouse gas emissions from industrialized nations will grow substantially over the next decade. However, if it comes into force, the Kyoto Protocol will require industrialized nations to reduce emissions to an average of 5% below 1990 levels in the 2008-2012 period. Taking early action to close this gap has a number of advantages. It reduces the risks of passing thresholds that trigger climate change "surprises." Early action also increases future generations' ability to choose greater levels of climate protection, and it leads to faster reductions of other pollutants. From an economic sense, early action is important because it allows shifts to less carbon-intensive technologies during the course of normal capital stock turnover. Moreover, many options for emission reduction have negative costs, and thus are economically worthwhile, because of paybacks in energy costs, healthcare costs, and other benefits. Finally, early emission reductions enhance the probability of successful ratification and lower the risk of noncompliance with the protocol. We discuss policy approaches for the period prior to 2008. Disadvantages of the current proposals for Credit for Early Action are the possibility of adverse selection due to problematic baseline calculation methods as well as the distributionary impacts of allocating a part of the emissions budget already before 2008. One simple policy without drawbacks is the so-called baseline protection, which removes the disincentive to early action due to the expectation that businesses may, in the future, receive emission rights in proportion to past emissions. It is particularly important to adopt policies that shift investment in long-lived capital stock towards less carbon-intensive technologies and to encourage innovation and technology development that will reduce future compliance costs. PMID:11531233
Michaelowa, A; Rolfe, C
Cars, carbon, and Kyoto: Evaluating an emission charge and other policy instruments as incentives for a transition to hybrid cars in New Zealand
Transition to hybrid petrol\\/electric vehicles (HEVs) is one means among many of reducing carbon emissions pursuant to the New Zealand emissions reduction targets under the Kyoto Protocol. The potential financial incentive value of an emissions charge was evaluated by comparing purchase and running costs of an HEV with an equivalent petrol?fuelled car. Had a carbon tax of $15\\/tonne CO2 operated
B. B. Gleisner; S. A. Weaver
Reduced carbon uptake during the 2010 Northern Hemisphere summer from GOSAT
NASA Astrophysics Data System (ADS)
Column-averaged dry air mole fractions of carbon dioxide (XCO2) measured by the Greenhouse Gases Observing Satellite (GOSAT) reveal significant interannual variation (IAV) of CO2uptake during the Northern Hemisphere summer between 2009 and 2010. The XCO2drawdown in 2010 is shallower than in 2009 by 2.4 ppm and 3.0 ppm over North America and Eurasia, respectively. Reduced carbon uptake in the summer of 2010 is most likely due to the heat wave in Eurasia driving biospheric fluxes and fire emissions. A joint inversion of GOSAT and surface data estimates an integrated biospheric and fire emission anomaly in April-September of 0.89 ▒0.20 PgC over Eurasia. In contrast, inversions of surface measurements alone fail to replicate the observed XCO2IAV and underestimate emission IAV over Eurasia. This shows the value of GOSAT XCO2in constraining the response of land-atmosphere exchange of CO2 to climate events.
Guerlet, S.; Basu, S.; Butz, A.; Krol, M.; Hahne, P.; Houweling, S.; Hasekamp, O. P.; Aben, I.
Modeling stand level carbon emissions from Canadian forest fires
NASA Astrophysics Data System (ADS)
Wildland fires in Canada burn an average of 2.8 million ha of forest annually. In years of extreme forest fire activity, total carbon emissions from wildland fires approach levels similar to Canadian industrial carbon emissions. There is large variability in carbon emissions rate (t per ha) within an individual fire due to fire behaviour and fuel variability. Large ( greater than 200 ha) fires account for about 97 percent of the annual area burned in Canada and they typically burn a wide range of fuel types and fuel loads under weather conditions that change as the fire spreads across the landscape. This causes large spatial and temporal variation in fuel consumption and therefore, carbon emissions. Variability in fuel consumption is well- documented by previous experimental burning projects in jack pine (Pinus banksiana) stands, a frequently burned component of the Canadian forest. Detailed fuel data from those studies show total fuel consumption rates of 0.8 to 5.4 kg per sq m in fires with intensities of 134 to 93 476 kW per m. The greatest range in fuel consumption rate occurred in the forest floor component where 28 to 74 percent of the initial forest floor material was burned, representing fuel consumption of 0.2 to 2.8 kg per sq m. By contrast, the overstory fuel consumption rate was 10 to 25 percent (0.6 to 2.2 kg per sq m) of the initial fuel load. Dead and downed woody fuel consumption generally represented a small amount of the total fuel consumption due to the limited initial fuel load. The wide range of total fuel consumption in this single fuel type was caused by variability in pre-fire fuel characteristics (fuel size, distribution, and total load), and burning conditions as influenced by weather, which affected fuel moisture content. In other fuel types characterized by deeper organic soils such as black spruce (Picea marianna), there is greater potential for a wider range of total fuel consumption due to higher forest floor fuel loads. To estimate wildland fire carbon emissions in Canada for international reporting, fire weather (FWI System) and pre-burn fuel data are used to calculate fire behaviour and determine fuel consumption for individual stand components (forest floor, aboveground live trees, standing dead snags, dead and downed woody debris) using the Boreal Fire Effects Model. A summary of these models, procedures, and levels of uncertainty, are presented.
de Groot, W. J.; McRae, D.
Carbon soundings: greenhouse gas emissions of the UK music industry
NASA Astrophysics Data System (ADS)
Over the past decade, questions regarding how to reduce human contributions to climate change have become more commonplace and non-nation state actorsŚsuch as businesses, non-government organizations, celebritiesŚhave increasingly become involved in climate change mitigation and adaptation initiatives. For these dynamic and rapidly expanding spaces, this letter provides an accounting of the methods and findings from a 2007 assessment of greenhouse gas (GHG) emissions in the UK music industry. The study estimates that overall GHG emissions associated with the UK music market are approximately 540 000 t CO2e per annum. Music recording and publishing accounted for 26% of these emissions (138 000 t CO2e per annum), while three-quarters (74%) derived from activities associated with live music performances (400 000 t CO2e per annum). These results have prompted a group of music industry business leaders to design campaigns to reduce the GHG emissions of their supply chains. The study has also provided a basis for ongoing in-depth research on CD packaging, audience travel, and artist touring as well as the development of a voluntary accreditation scheme for reducing GHG emissions from activities of the UK music industry.
Bottrill, C.; Liverman, D.; Boykoff, M.
Reduced Nitrous Oxide Emissions in Tomato Cropping Systems under Drip Irrigation and Fertigation
NASA Astrophysics Data System (ADS)
In California, agriculture and forestry account for 8% of the total greenhouse gas (GHG) emissions, of which 50% is accounted for by nitrous oxide (N2O). Furrow irrigation and high temperatures in the Central Valley, together with conventional fertilization, are ideal for the production of food, but also N2O. These conditions lead to high N2O fluxes, but also mean there is great potential to reduce N2O emissions by optimizing fertilizer use and irrigation practices. Improving fertilizer use by better synchronizing nitrogen (N) availability and crop demand can reduce N losses and fertilizer costs. Smaller, more frequent fertilizer applications can increase the synchrony between available soil N and crop N uptake. Fertigation allows for more control over how much N is being added and can therefore allow for better synchrony throughout the growing season. In our study, we determined how management practices, such as fertilization, irrigation, tillage and harvest, affect direct N2O emissions in typical tomato cropping systems. We evaluated two contrasting irrigation managements and their associated fertilizer application method, i.e. furrow irrigation and knife injection versus drip irrigation and fertigation. Across two tomato-growing seasons, we found that shifts in fertilizer and irrigation water management directly affect GHG emissions. Seasonal N2O fluxes were 3.4 times lower under drip versus furrow irrigation. In 2010, estimated losses of fertilizer N as N2O were 0.60 ▒ 0.06 kg N2O-N ha-1 yr-1 in the drip system versus 2.06 ▒ 0.11 N2O-N kg ha-1 yr-1 in the furrow system, which was equivalent to 0.29% and 0.87% of the added fertilizer, respectively. Carbon dioxide (CO2) emissions were also lower in the drip system (2.21 ▒ 0.16 Mg CO2-C ha-1 yr-1) than the furrow system (4.65 ▒ 0.23 Mg CO2-C ha-1 yr-1). Soil mineral N, dissolved organic carbon and soil moisture also varied between the two systems and correlated positively with N2O and CO2 emissions, depending on the management event and sampling position. Soil ammonium and nitrate exposure, used as indexes of substrate availability, were significantly lower in the drip system (1.43 ▒ 0.06 mg NH4-N yr-1 and 10.75 ▒ 0.08 mg NO3-N yr-1) compared to the furrow system (2.93 ▒ 0.09 mg NH4-N yr-1 and 18.06 ▒ 0.44 mg NO3-N yr-1). These changes in irrigation water and fertilizer management also increased crop yield in the drip system, highlighting the potential for concomitant increased yields and reduced GHG emissions through the use of fertigation techniques.
Kennedy, T.; Suddick, E. C.; Six, J. W.
Scanning tunneling microscopy and field emission studies of carbon nanostructures
NASA Astrophysics Data System (ADS)
This thesis is divided into three sections. The first section describes the design and construction of an ultrahigh vacuum, low temperature, high magnetic field, scanning tunneling microscope (STM) system. This system has been designed specifically for the characterization of nanometer-scale materials with low-dimensional electronic properties, and for the manipulation and modification of these materials to fabricate novel electronic devices. The successful operation of this system marks the beginning of a long term, potentially fruitful research program. The second section discusses experiments performed with an STM on two carbon materials. The first material is the fullerene molecule C36, which is investigated through scanning tunneling spectroscopy. These measurements prove C36 to be a material with an 0.8 eV electronic gap and sharp, molecular-like electronic energy levels. However, the spacing of these levels varies slightly from the theoretical predictions for isolated C36 molecules. Through further analysis, a new, dimerized C36 morphology is proposed and a better appreciation of the high chemical reactivity of this material is gained. Carbon nanotubes are a second material studied in this thesis. Besides conventional STM measurements, length-dependent transport characteristics of nanotubes are measured using the STM tip as a sliding electrical contact. These measurements identify unusual transport properties which appear to be initiated at particular physical positions along a nanotube. The behavior agrees with theoretical models in which a defect is incorporated in a carbon nanotube, indicating that the control of such defects may be a critical issue in the development of nanotube-based electronic devices. The third section of this thesis discusses field emission characteristics of carbon nanotube-filled composites. Nanotube-based field emission sources are shown to have excellent device characteristics which meet or exceed all of the requirements of commercial, high intensity, field emission sources. Surprisingly, though, a quantitative analysis of the emission current reveals that the nanotubes are not conventional emitters at all. Instead, they display a variety of interesting behaviors including an unusually low voltage onset, an anomalously sharp current increase above the onset, and a high field regime in which nanotube interactions tend to smooth and stabilize the field emission current. By looking beyond conventional field emission theory, each of these behaviors may be understood in terms of nanotube properties.
Collins, Philip Godfrey
Reducing Open Cell Landfill Methane Emissions with a Bioactive Alternative Daily.
National Technical Information Service (NTIS)
Methane and carbon dioxide are formed in landfills as wastes degrade. Molecule-for-molecule, methane is about 20 times more potent than carbon dioxide at trapping heat in the earth's atmosphere, and thus, it is the methane emissions from landfills that ar...
D. Jones H. Hilger J. Bogner J. Oliver
Low emission zones reduce PM10 mass concentrations and diesel soot in German cities.
In many European cities mass concentrations of PM10 (particles less than 10 microm in size) are still exceeding air quality standards as set by the European Commission in 1999. As a consequence, many cities introduced low emission zones (LEZs) to improve air quality and to meet the limit values. In Germany currently 48 LEZs are in operation. By means of dispersion modeling, PM10 concentrations were estimated to decrease up to 10%. Analysis of PM10 levels conducted for Cologne, Berlin, and Munich some time after the LEZs were introduced showed reduction of PM10 mass concentration in the estimated range. The PM10 particle fraction is, however composed of particles with varying toxicity, of which diesel soot is highly health relevant. An evaluation of air quality data conducted in Berlin showed that in 2010 traffic-related soot concentrations measured along major roads decreased by 52% compared to 2007. Diesel particle emissions in Berlin were reduced in 2012 by 63% compared to a business-as-usual scenario (reference year 2007). A strong reduction of the traffic-related particle fraction of PM2.5 was also reported for Munich. Therefore, it is likely that the effects of LEZs are considerably more significant to human health than was anticipated when only considering the reduction of PM10 mass concentrations. Implications: The implementation of low emission zones in German cities might result in a reduction of PM10 levels concentrations by up to 10%. However, it is difficult to show a reduction of PM10 annual averages in this order of magnitude as meteorology has a large impact on the year-to-year variation of PM mass concentrations. Monitoring of other PM metrics such as black smoke (BS) or elemental carbon (EC) might be a better strategy for evaluating LEZs effects. The benefit of low emission zones on human health is far greater than is presently visible from routine measurements of PM10. PMID:24843918
Cyrys, Josef; Peters, Annette; Soentgen, Jens; Wichmann, H Erich
Avgassutslipp fra innenriks sjoetransport. Aktuelle utslippsreduserende tiltak. (Exhaust emissions from the coastal fleet in Norway. Possible measures to reduce emissions).
National Technical Information Service (NTIS)
The report describes possible technological measures to reduce emissions of NOx, HC, CO and particles from engines in use in the Norwegian coastal fleet. The costs and applicability of the most probable measures are discussed for various engine types. 45 ...
O. Melhus P. K. Bremnes
Northern Eurasian Wetlands and the Carbon Cycle: Model Estimates of Carbon Storage and Methane Emissions
NASA Astrophysics Data System (ADS)
The Eurasian Arctic drainage constitutes over ten percent of the global land area, and stores a substantial fraction of the terrestrial carbon pool in its soils and boreal forests. Specifically, boreal forests in this region constitute an estimated carbon sink of 0.5 Pg/y. However, assessments of carbon storage and fluxes in this region, and their role in climate change, vary considerably due to large uncertainties in the extent of wetlands, which both store carbon as peat and emit carbon as methane. Accurate estimates of wetland extent have been confounded by insufficient resolution of satellite imagery and poor coverage of in situ observations. In this study we refine these estimates of wetland extent, carbon storage, and methane emissions using a system of linked large-scale models of hydrology, terrestrial carbon dynamics, and methane emissions. Large-scale hydrology comes from the Variable Infiltration Capacity (VIC) hydrological model, which includes an updated lake/wetland parameterization that estimates the water table depth as a function of both lake level and wetland soil moisture. Fast ecosystem processes such as photosynthesis and respiration are simulated via the Biosphere Energy-Transfer Hydrology (BETHY) terrestrial carbon model. Methane emissions in areas of open water or saturated soil are simulated with the Walter-Heimann methane model. We validate this modeling system with respect to in situ observations of soil moisture and temperature, evaporation, and fluxes of CO2 and methane at flux towers at Fyodorovskoje, Hakasia, and Cherskii, Russia, over the period 1998- 2004. Sensitivity to calibration parameters such as the rooting depth and the proportionality between methane production rate and NPP are also explored.
Bohn, T. J.; Lettenmaier, D. P.; Sathulur, K.; Bowling, L. C.; McDonald, K. C.
Emission reduction of NOx, PM, PM-carbon, and PAHs from a generator fuelled by biodieselhols.
This investigation examines the particulate matter (PM), particulate carbon, polycyclic aromatic hydrocarbons (PAHs), and nitrogen oxides (NOx) emitted from a generator fueled by petroleum diesel blended with waste-edible-oil-biodiesel and water-containing acetone. Experimental results show that using biodieselhols with water-containing (or pure) acetone as the fuel of generator, in comparison to using petroleum diesel, significantly reduces PM emission; roughly, this reduction increased as percentage of water-containing acetone increased. When the percentages of waste-edible-oil-biodiesel were ?5vol%, adding pure or water-containing acetone (1-3vol%) to biodieselhols generated emission reductions of NOx, PM, particle-bound organic carbon (OC), total-PAHs, and total-BaPeq. Consequently, using water-containing acetone biodieselhols as an alternative generator fuel is feasible and helps recycle and reuse waste solvents containing water-containing acetone. PMID:24797907
Tsai, Jen-Hsiung; Chen, Shui-Jen; Huang, Kuo-Lin; Lin, Wen-Yinn; Lee, Wen-Jhy; Chao, How-Ran; Lin, Chih-Chung; Hsieh, Lien-Te
Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario
NASA Astrophysics Data System (ADS)
The realization that mitigation efforts to reduce carbon dioxide emissions have, until now, been relatively ineffective has led to an increasing interest in climate engineering as a possible means of preventing the potentially catastrophic consequences of climate change. While many studies have addressed the potential effectiveness of individual methods there have been few attempts to compare them. Here we use an Earth system model to compare the effectiveness and side effects of afforestation, artificial ocean upwelling, ocean iron fertilization, ocean alkalinization and solar radiation management during a high carbon dioxide-emission scenario. We find that even when applied continuously and at scales as large as currently deemed possible, all methods are, individually, either relatively ineffective with limited (<8%) warming reductions, or they have potentially severe side effects and cannot be stopped without causing rapid climate change. Our simulations suggest that the potential for these types of climate engineering to make up for failed mitigation may be very limited.
Keller, David P.; Feng, Ellias Y.; Oschlies, Andreas
Increases in terrestrially derived carbon stimulate organic carbon processing and CO2 emissions in boreal aquatic ecosystems
NASA Astrophysics Data System (ADS)
The concentrations of terrestrially derived dissolved organic carbon have been increasing throughout northern aquatic ecosystems in recent decades, but whether these shifts have an impact on aquatic carbon emissions at the continental scale depends on the potential for this terrestrial carbon to be converted into carbon dioxide. Here, via the analysis of hundreds of boreal lakes, rivers and wetlands in Canada, we show that, contrary to conventional assumptions, the proportion of biologically degradable dissolved organic carbon remains constant and the photochemical degradability increases with terrestrial influence. Thus, degradation potential increases with increasing amounts of terrestrial carbon. Our results provide empirical evidence of a strong causal link between dissolved organic carbon concentrations and aquatic fluxes of carbon dioxide, mediated by the degradation of land-derived organic carbon in aquatic ecosystems. Future shifts in the patterns of terrestrial dissolved organic carbon in inland waters thus have the potential to significantly increase aquatic carbon emissions across northern landscapes.
Lapierre, Jean-Franšois; Guillemette, Franšois; Berggren, Martin; Del Giorgio, Paul A.
Parameterized MPC to reduce dispersion of road traffic emissions
This paper has two main contributions. First, it presents a simple area-wide emission (or dispersion) model for a freeway traffic networks. The model takes the variation of the wind speed and direction into account. Second, it presents a nonlinear parameterized MPC controller for freeway traffic systems. Next, the proposed model and control approach are illustrated with a simulation-based case study.
S. K. Zegeye; B. De Schutter; J. Hellendoorn; E. A. Breunesse
Innovative Technology Reduces Power Plant Emissions-Commercialization Success
NASA Technical Reports Server (NTRS)
Overview of emission control system development: (1) Development of new oxidizer scrubber system to eliminate NOx waste and produce fertilizer (2) Technology licensed and a 1 to 3 MWatt-scale prototype installed on power plant (3) Development of method to oxidize NO to NO2 (4) Experience gained from licensing NASA technology.
Parrish, Clyde; Chung, Landy
Carbon stocks of intact mangroves and carbon emissions arising from their conversion in the Dominican Republic.
Mangroves are recognized to possess a variety of ecosystem services including high rates of carbon sequestration and storage. Deforestation and conversion of these ecosystems continue to be high and have been predicted to result in significant carbon emissions to the atmosphere. Yet few studies have quantified the carbon stocks or losses associated with conversion of these ecosystems. In this study we quantified the ecosystem carbon stocks of three common mangrove types of the Caribbean as well as those of abandoned shrimp ponds in areas formerly occupied by mangrove-a common land-use conversion of mangroves throughout the world. In the mangroves of the Montecristi Province in Northwest Dominican Republic we found C stocks ranged from 706 to 1131 Mg/ha. The medium-statured mangroves (3-10 m in height) had the highest C stocks while the tall (> 10 m) mangroves had the lowest ecosystem carbon storage. Carbon stocks of the low mangrove (shrub) type (< 3 m) were relatively high due to the presence of carbon-rich soils as deep as 2 m. Carbon stocks of abandoned shrimp ponds were 95 Mg/ha or approximately 11% that of the mangroves. Using a stock-change approach, the potential emissions from the conversion of mangroves to shrimp ponds ranged from 2244 to 3799 Mg CO2e/ha (CO2 equivalents). This is among the largest measured C emissions from land use in the tropics. The 6260 ha of mangroves and converted mangroves in the Montecristi Province are estimated to contain 3,841,490 Mg of C. Mangroves represented 76% of this area but currently store 97% of the carbon in this coastal wetland (3,696,722 Mg C). Converted lands store only 4% of the total ecosystem C (144,778 Mg C) while they comprised 24% of the area. By these metrics the replacement of mangroves with shrimp and salt ponds has resulted in estimated emissions from this region totaling 3.8 million Mg CO2e or approximately 21% of the total C prior to conversion. Given the high C stocks of mangroves, the high emissions from their conversion, and the other important functions and services they provide, their inclusion in climate-change mitigation strategies is warranted. PMID:24834737
Kauffman, J Boone; Heider, Chris; Norfolk, Jennifer; Payton, Frederick
High Arctic wetting reduces permafrost carbon feedbacks to climate warming
NASA Astrophysics Data System (ADS)
The carbon (C) balance of permafrost regions is predicted to be extremely sensitive to climatic changes. Major uncertainties exist in the rate of permafrost thaw and associated C emissions (33-508PgC or 0.04-1.69░C by 2100; refs , ) and plant C uptake. In the High Arctic, semi-deserts retain unique soil-plant-permafrost interactions and heterogeneous soil C pools (>12PgC ref. ). Owing to its coastal proximity, marked changes are expected for High Arctic tundra. With declining summer sea-ice cover, these systems are simultaneously exposed to rising temperatures, increases in precipitation and permafrost degradation. Here we show, using measurements of tundra-atmosphere C fluxes and soil C sources (14C) at a long-term climate change experiment in northwest Greenland, that warming decreased the summer CO2 sink strength of semi-deserts by up to 55%. In contrast, warming combined with wetting increased the CO2 sink strength by an order of magnitude. Further, wetting while relocating recently assimilated plant C into the deep soil decreased old C loss compared with the warming-only treatment. Consequently, the High Arctic has the potential to remain a strong C sink even as the rest of the permafrost region transitions to a net C source as a result of future global warming.
Lupascu, M.; Welker, J. M.; Seibt, U.; Maseyk, K.; Xu, X.; Czimczik, C. I.
Impact of inland shipping emissions on elemental carbon concentrations near waterways in The Netherlands
NASA Astrophysics Data System (ADS)
This study aims to quantify the impact of black carbon from inland shipping on air quality, expressed as elemental carbon (EC) near inland waterways in The Netherlands. Downwind measurements of particle numbers and EC were used to establish emission factors for EC from inland shipping using inverse modelling. These emission factors were combined with data on energy consumption to derive annual average emissions rates for all Dutch waterways. A line source model was applied to compute the contribution of inland shipping to annual average EC concentrations for around 140,000 people living within 200ám of busy waterways in The Netherlands. The results showed that they are exposed to additional EC concentrations of up to 0.5á?gáEC per m3 depending on the shipping volume and distance from the waterway. In view of the envisaged growth in water transport, this underlines the need to reduce combustion emissions from inland shipping. Targeting "gross" polluters may be the most effective approach since 30% of ships cause more than 80% of the total emissions.
Keuken, M. P.; Moerman, M.; Jonkers, J.; Hulskotte, J.; Denier van der Gon, H. A. C.; Hoek, G.; Sokhi, R. S.
Return to 1990: The cost of mitigating United States carbon emissions in the post-2000 period
The Second Generation Model (SGM) is employed to examine four hypothetical agreements to reduce emissions in Annex 1 nations (OECD nations plus most of the nations of Eastern Europe and the former Soviet Union) to levels in the neighborhood of those which existed in 1990, with obligations taking effect in the year 2010. The authors estimate the cost to the US of complying with such agreements under three distinct conditions: no trading of emissions rights, trading of emissions rights only among Annex 1 nations, and a fully global trading regime. The authors find that the marginal cost of returning to 1990 emissions levels in the US in the absence of trading opportunities is approximately $108 per metric ton carbon in 2010. The total cost in that year is approximately 0.2% of GDP. International trade in emissions permits lowers the cost of achieving any mitigation objective by equalizing the marginal cost of carbon mitigation among countries. For the four mitigation scenarios in this study, economic costs to the US remain below 1% of GDP through at least the year 2020.
Edmonds, J.A.; Kim, S.H.; MacCracken, C.N.; Sands, R.D.; Wise, M.A.
Solid fuels vary significantly with respect to the amount of CO{sub 2} directly produced per unit heating value. Elemental carbon is notably worse than other solid fuels in this regard, and since carbon (char) is an intermediate product of the combustion of almost all solid fuels, there is an opportunity to reduce specific CO{sub 2} emissions by reconfiguring processes to avoid char combustion wholly or in part. The primary goal of this one-year Innovative Concepts project is to make a fundamental thermodynamic assessment of three modes of solid fuel use: (1) combustion, (2) carbonization, and (3) oxidative pyrolysis, for a wide range of coal and alternative solid fuels. This period a large set of thermodynamic calculations were carried out to assess the potential of the three processes. The results show that the net carbon dioxide emissions and the relative ranking of the different processes depends greatly on the particular baseline fossil fuel being displaced by the new technology. As an example, in a baseline natural gas environment, it is thermodynamically more advantageous to carbonize biomass than to combust it, and even more advantageous to oxidatively pyrolyze the biomass.
Robert Hurt; Todd Lang
Quantifying the emissions and air quality co-benefits of lower-carbon electricity production
NASA Astrophysics Data System (ADS)
The impact of air emissions from electricity generation depends on the spatial distribution of power plants and electricity dispatch decisions. Thus, any realistic evaluation of the air quality impacts of lower-carbon electricity must account for the spatially heterogeneous changes in associated emissions. Here, we present an analysis of the changes in fine particulate matter (PM2.5) associated with current, expected, and proposed energy efficiency and renewable energy policies in Wisconsin. We simulate the state's electricity system and its potential response to policies using the MyPower electricity-sector model, which calculates plant-by-plant reductions in NOx and SO2 emissions. We find that increased efficiency and renewable generation in a 2024 policy scenario substantially reduce statewide emissions of NOx and SO2 (55% and 59% compared to 2008, 32% and 33% compared to 2024 business-as-usual, BAU). PM2.5 is quantified across the Great Lakes region using the EPA Community Multiscale Air Quality (CMAQ) model for some emissions scenarios. We find that summer mean surface concentrations of sulfate and PM2.5 are less sensitive to policy changes than emissions. In the 2024 policy scenario, sulfate aerosol decreases less than 3% over most of the region relative to BAU and 3-13% relative to 2008 over most of Wisconsin. The lower response of these secondary aerosols arises from chemical and meteorological processing of electricity emissions, and mixing with other emission sources. An analysis of model performance and response to emission reduction at five sites in Wisconsin shows good model agreement with observations and a high level of spatial and temporal variability in sulfate and PM2.5 reductions. In this case study, the marginal improvements in emissions and air quality associated with carbon policies were less than the technology, renewable, and conservation assumptions under a business-as-usual scenario. However, this analysis for Wisconsin shows how integrated modeling can quantify the emission and air quality co-benefits associated with carbon reduction measures, and this approach can be applied to other regions and larger geographical scales.
Plachinski, Steven D.; Holloway, Tracey; Meier, Paul J.; Nemet, Gregory F.; Rrushaj, Arber; Oberman, Jacob T.; Duran, Phillip L.; Voigt, Caitlin L.
Irreversible climate change due to carbon dioxide emissions
The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450ľ600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the ôdust bowlö era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4ľ1.0 m if 21st century CO2 concentrations exceed 600 ppmv and 0.6ľ1.9 m for peak CO2 concentrations exceeding ?1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer.
Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre
Irreversible climate change due to carbon dioxide emissions.
The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450-600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the "dust bowl" era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4-1.0 m if 21st century CO(2) concentrations exceed 600 ppmv and 0.6-1.9 m for peak CO(2) concentrations exceeding approximately 1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer. PMID:19179281
Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre
Management options for reducing CO2 emissions from agricultural soils
Crop-based agriculture occupies 1.7 billion hectares, globally, with a soil C stock of about 170 Pg. Of the past anthropogenic CO2 additions to the atmosphere, about 50 Pg C came from the loss of soil organic matter (SOM) in cultivated soils. Improved management practices, however, can rebuild C stocks in agricultural soils and help mitigate CO2 emissions. Increasing soil C
Reduced iron induced nitric oxide and nitrous oxide emission.
Formation of the greenhouse gas nitrous oxide in water treatment systems is predominantly studied as a biological phenomenon. There are indications that also chemical processes contribute to these emissions. Here we studied the formation of nitric oxide (NO) and nitrous oxide (N(2)O) due to chemical nitrite reduction by ferrous iron (Fe(II)). Reduction of nitrite and NO coupled to Fe(II) oxidation was studied in laboratory-scale chemical experiments at different pH, nitrite and iron concentrations. The continuous measurement of both NO and N(2)O emission showed that nitrite reduction and NO reduction have different kinetics. Nitrite reduction shows a linear dependency on the nitrite concentration, implying first order kinetics in nitrite. The nitrite reduction seems to be an equilibrium based reaction, leading to a constant NO concentration in the liquid. The NO reduction rate is suggested to be most dependent on reactive surface availability and the sorption of Fe(II) to the reactive surface. The importance of emission of NO and N(2)O coupled to iron oxidation is exemplified by iron reduction experiments and several examples of environments where this pathway can play a role. PMID:21940030
Kampschreur, Marlies J; Kleerebezem, Robbert; de Vet, Weren W J M; van Loosdrecht, Mark C M
An assessment of monitoring requirements and costs of 'Reduced Emissions from Deforestation and Degradation'
Background Negotiations on a future climate policy framework addressing Reduced Emissions from Deforestation and Degradation (REDD) are ongoing. Regardless of how such a framework will be designed, many technical solutions of estimating forest cover and forest carbon stock change exist to support policy in monitoring and accounting. These technologies typically combine remotely sensed data with ground-based inventories. In this article we assess the costs of monitoring REDD based on available technologies and requirements associated with key elements of REDD policy. Results We find that the design of a REDD policy framework (and specifically its rules) can have a significant impact on monitoring costs. Costs may vary from 0.5 to 550 US$ per square kilometre depending on the required precision of carbon stock and area change detection. Moreover, they follow economies of scale, i.e. single country or project solutions will face relatively higher monitoring costs. Conclusion Although monitoring costs are relatively small compared to other cost items within a REDD system, they should be shared not only among countries but also among sectors, because an integrated monitoring system would have multiple benefits for non-REDD management. Overcoming initialization costs and unequal access to monitoring technologies is crucial for implementation of an integrated monitoring system, and demands for international cooperation.
Bottcher, Hannes; Eisbrenner, Katja; Fritz, Steffen; Kindermann, Georg; Kraxner, Florian; McCallum, Ian; Obersteiner, Michael
Reducing energy-related CO2 emissions using accelerated weathering of limestone
The use and impacts of accelerated weathering of limestone (AWL; reaction: CO2+H2O+CaCO3???Ca2++2(HCO3-) is explored as a CO2 capture and sequestration method. It is shown that significant limestone resources are relatively close to a majority of CO2-emitting power plants along the coastal US, a favored siting location for AWL. Waste fines, representing more than 20% of current US crushed limestone production (>109 tonnes/yr), could provide an inexpensive or free source of AWL carbonate. With limestone transportation then as the dominant cost variable, CO2 mitigation costs of $3-$4/tonne appear to be possible in certain locations. Perhaps 10-20% of US point-source CO2 emissions could be mitigated in this fashion. It is experimentally shown that CO2 sequestration rates of 10-6 to 10-5 moles/sec per m2 of limestone surface area are achievable, with reaction densities on the order of 10-2 tonnes CO2 m-3day-1, highly dependent on limestone particle size, solution turbulence and flow, and CO2 concentration. Modeling shows that AWL would allow carbon storage in the ocean with significantly reduced impacts to seawater pH relative to direct CO2 disposal into the atmosphere or sea. The addition of AWL-derived alkalinity to the ocean may itself be beneficial for marine biota. ?? 2006 Elsevier Ltd. All rights reserved.
Rau, G. H.; Knauss, K. G.; Langer, W. H.; Caldeira, K.
Trade-offs between solar radiation management, carbon dioxide removal, emissions mitigation and adaptation
The possible use of solar radiation control strategies to counteract global warming is explored through a number scenarios of different anthropogenic CO2 emission reduction pathways and carbon dioxide removal interventions. Using a simple Earth system model, we illustrate the trade-offs between CO2 emission reduction, the use of carbon dioxide removal geoengineering interventions (`negative emissions') and solar radiation management (SRM). These
Naomi Vaughan; Timothy Lenton
Emissions of black carbon and co-pollutants emitted from diesel vehicles in the Mexico City Metropolitan Area
NASA Astrophysics Data System (ADS)
Black carbon emitted from freight, public transport, and heavy duty trucks sources is linked with adverse effects on human health. In addition, the control of emissions of black carbon, an important short-lived climate forcing agent (SLCF), has recently been considered as one of the key strategies for mitigating regional near-term climate change. Despite the availability of new emissions control technologies for reducing emissions from diesel-powered mobile sources, their introduction is still not widespread in many urban areas and there is a need to characterize real-world emission rates of black carbon from this key source. The emissions of black carbon, organic carbon, and other gaseous and particle pollutants from diesel-powered mobile sources in Mexico were characterized by deploying a mobile laboratory equipped with real-time instrumentation in Mexico City as part of the SLCFs-Mexico 2013 project. From February 25-28 of 2013 the emissions from selected diesel-powered vehicles were measured in both controlled experiments and real-world on-road driving conditions. Sampled vehicles had several emissions levels technologies, including: EPA98, EPA03, EPA04, EURO3-5, and Hybrid. All vehicles were sampled using diesel fuel and several vehicles were measured using both diesel and biodiesel fuels. Additional measurements included the use of a remote sensing unit for the co-sampling of all tested vehicles, and the installation and operation of a Portable Emissions Measurements System (PEMS) for the measurement of emissions from a test vehicle. We will present inter-comparisons of the emission factors obtained among the various vehicle technologies that were sampled during the experiment as well as the inter-comparison of results from the various sampling platforms. The results can be used to
Zavala, Miguel; Molina, Luisa T.; Fortner, Edward; Knighton, Berk; Herndon, Scott; Yacovitch, Tara; Floerchinger, Cody; Roscioli, Joseph; Kolb, Charles; Mejia, Jose Antonio; Sarmiento, Jorge; Paramo, Victor Hugo; Zirath, Sergio; Jazcilevich, Aron
Carbon emissions and sequestration in forests: Case studies from seven developing countries
Estimates of carbon emissions from deforestation in Mexico are derived for the year 1985 and for two contrasting scenarios in 2025. Carbon emissions are calculated through an in-depth review of the existing information on forest cover deforestation mtes and area affected by forest fires as well as on forests' carbon-related biological characteristics. The analysis covers both tropical -- evergreen and
W. Makundi; J. Sathaye; O. M. Cerutti; M. J. Ordonez; R. D. Minjarez
Carbon emissions and sequestration in forests: Case studies from seven developing countries. Volume 4: Mexico: Draft
Estimates of carbon emissions from deforestation in Mexico are derived for the year 1985 and for two contrasting scenarios in 2025. Carbon emissions are calculated through an in-depth review of the existing information on forest cover deforestation mtes and area affected by forest fires as well as on forests` carbon-related biological characteristics. The analysis covers both tropical -- evergreen and
W. Makundi; J. Sathaye; O. M. Cerutti; M. J. Ordonez; R. D. Minjarez
Thermal emission spectra from individual suspended carbon nanotubes.
We study the thermal emission spectra of individual suspended carbon nanotubes induced by electrical heating. Semiconducting and metallic devices exhibit different spectra, based on their distinctive band structures. These spectra are compared with the ideal blackbody emission spectrum. In the visible wavelength range, the thermal emission spectra of semiconducting devices agree well with Planck's law, while the spectra of metallic devices show an additional peak between 1.5 and 1.9 eV. In the near-infrared wavelength range, the semiconducting nanotubes exhibit a peak around 1 eV. These additional peaks are attributed to the E11M and E22SC transitions that are thermally driven under these high applied bias voltages. These peaks show a strong polarization dependence, while the blackbody tail is unpolarized, which provides further evidence for electron-hole recombination in thermal emission. For semiconducting devices, the temperature of the nanotube is fit to Planck's law and compared with the temperatures obtained from the G band and 2D band Raman downshifts, as well as the anti-Stokes/Stokes intensity ratio. For devices showing thermal non-equilibrium, the electron temperature agrees well with G+ downshift but deviates from G_ downshift. PMID:21545117
Liu, Zuwei; Bushmaker, Adam; Aykol, Mehmet; Cronin, Stephen B
Carbon monoxide fourth positive ultraviolet airglow emissions on Venus
The ultraviolet spectrometer experiment aboard the Pioneer Venus orbiting spacecraft has recorded airglow spectra of the carbon monoxide (CO) fourth positive emission bands in the lambda 1250-1800 A spectra region. Extended duration of the PV mission since the December 4, 1978 orbit insertion has afforded opportunity to obtain many disc spectra, composite disc images and limb emission altitude profiles of the strongest (CO(A'..pi -->..X'..sigma../sup +/) electronic bands. Data have been analyzed in terms of high resolution theoretical synthetic spectra calculated from a detailed multiple scattering radiative transfer model which postulates population of the excited ..pi.. electronic state by the mechanisms of solar resonance absorption and photoelectron impact excitation of CO, excitation by solar ultraviolet photolysis and photoelectron impact dissociation of CO/sub 2/, and dissociative recombinatin of CO/sub 2//sup +/ ions with thermal electrons. The predominant emission sources prove to be solar resonance scattering and dissociative recombination for all bands except those of the v' = 14 vibrational progression which are excited solely by resonance absorption of solar Lyman-alpha. Agreement between theory and observations is quite good with discrepancies attributable to uncertainties in the solar flux and instrument calibration. The density distribution of CO molecules below the 137 km turbopause altitude is inferred from the (14,5) band limb emission profile.
Swanson, R.A.L.
Glycol dehydrators remove water from gas pipe lines. An advanced dehydrator by Engineered Concepts, Farmington, NM, saves a significant amount of gas, while reducing hazardous air pollutants, volatile organic compounds and CO2 air pollutants...
Reducible emission probabilities and thermal scaling in multifragmentation
Intermediate-mass-fragment multiplicity distributions for a variety of reactions at intermediate energies are shown to be binomial and thus reducible at all measured transverse energies. From these distributions a single binary event probability can be extracted that has a thermal dependence. A strong thermal signature is also found in the charge distributions. The {eta}-fold charge distributions are reducible to the {eta}-fold charge distributions through a simple scaling that is dictated by fold number and charge conservation.
Moretto, L.G.; Phair, L.; Tso, K. [and others
Emission factors of PAHs, methoxyphenols, levoglucosan, elemental carbon and organic carbon from simulated wheat and Kentucky bluegrass stubble burns
Emission factors (EFs) of pollutants from post-harvest agricultural burning are required for predicting downwind impacts of smoke and inventorying emissions. EFs of polycyclic aromatic hydrocarbons (PAH), methoxyphenols (MP), levoglucosan (LG), elemental carbon (EC) and organic carbon (OC) from wheat and Kentucky bluegrass (KBG) stubble burning were quantified in a US EPA test burn facility. The PAH and MP EFs for
Ranil Dhammapala; Candis Claiborn; Jorge Jimenez; Jeffrey Corkill; Brian Gullett; Christopher Simpson; Michael Paulsen
Inhibition of carbonic anhydrase reduces brain injury after intracerebral hemorrhage
Carbonic anhydrase-1 (CA-1) is a metalloenzyme present at high concentrations in erythrocytes. Our previous studies showed that erythrocyte lysis contributes to brain edema formation after intracerebral hemorrhage (ICH) and a recent study indicates that CA-1 can cause blood-brain barrier disruption. The present study investigated the role of CA-1 in ICH-induced brain injury. There were three groups in the study. In the first, adult male Sprague-Dawley rats received 100 ?l autologous blood injection into the right caudate. Sham rats had a needle insertion. Rat brains were used for brain CA-1 level determination. In the second group, rats received an intracaudate injection of either 50 ?l CA-1 (1 ?g/?l) or saline. Brain water content, microglia activation and neuronal death (Fluoro-Jade C staining) were examined 24 hours later. In the third group, acetazolamide (AZA, 5 ?l, 1 mM), an inhibitor of carbonic anhydrases, or vehicle was co-injected with 100 ?l blood. Brain water content, neuronal death and behavioral deficits were measured. We found that CA-I levels were elevated in the ipsilateral basal ganglia at 24 hours after ICH. Intracaudate injection of CA-1 induced brain edema (79.0 ▒ 0.6 vs. 78.0▒0.2% in saline group, p<0.01), microglia activation and neuronal death (p<0.01) at 24 hours. AZA, an inhibitor of CA, reduced ICH-induced brain water content (79.3 ▒ 0.7 vs. 81.0 ▒ 1.0% in the vehicle-treated group, p<0.05), neuronal death and improved functional outcome (p<0.05). These results suggest that CA-1 from erythrocyte lysis contributes to brain injury after ICH.
Guo, Fuyou; Hua, Ya; Wang, Jinhu; Keep, Richard F.; Xi, Guohua
Carbon, nitrogen balances and greenhouse gas emission during cattle feedlot manure composting.
Carbon and N losses reduce the agronomic value of compost and contribute to greenhouse gas (GHG) emissions. This study investigated GHG emissions during composting of straw-bedded manure (SBM) and wood chip-bedded manure (WBM). For SBM, dry matter (DM) loss was 301 kg Mg(-1), total carbon (TC) loss was 174 kg Mg(-1), and total nitrogen (TN) loss was 8.3 kg Mg(-1). These correspond to 30.1% of initial DM, 52.8% of initial TC, and 41.6% of initial TN. For WBM, DM loss was 268 kg Mg(-1), TC loss was 154 kg Mg(-1), and TN loss was 1.40 kg Mg(-1), corresponding to 26.5, 34.5, and 11.8% of initial amounts. Most C was lost as CO2 with CH4 accounting for <6%. However, the net contribution to greenhouse gas emissions was greater for CH4 since it is 21 times more effective at trapping heat than CO2. Nitrous oxide (N2O) emissions were 0.077 kg N Mg(-1) for SBM and 0.084 kg N Mg(-1) for WBM, accounting for 1 to 6% of total N loss. Total GHG emissions as CO2-C equivalent were not significantly different between SBM (368.4 +/- 18.5 kg Mg(-1)) and WBM (349.2 +/- 24.3 kg Mg(-1)). However, emission of 368.4 kg C Mg(-1) (CO2-C equivalent) was greater than the initial TC content (330.5 kg Mg(-1)) of SBM, raising the question of the net benefits of composting on C sequestration. Further study is needed to evaluate the impact of composting on overall GHG emissions and C sequestration and to fully investigate livestock manure management options. PMID:14964356
Hao, Xiying; Chang, Chi; Larney, Francis J
The Seasonal and Spatial Distribution of Carbon Dioxide Emissions from Fossil Fuels in Asia
NASA Astrophysics Data System (ADS)
Carbon dioxide emissions from fossil-fuel consumption are presented for the five Asian countries that are among the global leaders in anthropogenic carbon emissions: China (13% of global total), Japan (5% of global total), India (5% of global total), South Korea (2% of global total), and Indonesia (1% of global total). Together, these five countries represent over a quarter of the world's fossil-fuel based carbon emissions. Moreover, these countries are rapidly developing and energy demand has grown dramatically in the last two decades. A method is developed to estimate the spatial and seasonal flux of fossil-fuel consumption, thereby greatly improving the temporal and spatial resolution of anthropogenic carbon dioxide emissions. Currently, only national annual data for anthropogenic carbon emissions are available, and as such, no understanding of seasonal or sub-national patterns of emissions are possible. This methodology employs fuel distribution data from representative sectors of the fossil-fuel market to determine the temporal and spatial patterns of fuel consumption. These patterns of fuel consumption are then converted to patterns of carbon emissions. The annual total emissions estimates produced by this method are consistent to those maintained by the United Nations. Improved estimates of temporal and spatial resolution of the human based carbon emissions allows for better projections about future energy demands, carbon emissions, and ultimately the global carbon cycle.
Gregg, J. S.; Andres, R. J.
Committed carbon emissions, deforestation, and community land conversion from oil palm plantation expansion in West Kalimantan, Indonesia.
Industrial agricultural plantations are a rapidly increasing yet largely unmeasured source of tropical land cover change. Here, we evaluate impacts of oil palm plantation development on land cover, carbon flux, and agrarian community lands in West Kalimantan, Indonesian Borneo. With a spatially explicit land change/carbon bookkeeping model, parameterized using high-resolution satellite time series and informed by socioeconomic surveys, we assess previous and project future plantation expansion under five scenarios. Although fire was the primary proximate cause of 1989-2008 deforestation (93%) and net carbon emissions (69%), by 2007-2008, oil palm directly caused 27% of total and 40% of peatland deforestation. Plantation land sources exhibited distinctive temporal dynamics, comprising 81% forests on mineral soils (1994-2001), shifting to 69% peatlands (2008-2011). Plantation leases reveal vast development potential. In 2008, leases spanned ?65% of the region, including 62% on peatlands and 59% of community-managed lands, yet <10% of lease area was planted. Projecting business as usual (BAU), by 2020 ?40% of regional and 35% of community lands are cleared for oil palm, generating 26% of net carbon emissions. Intact forest cover declines to 4%, and the proportion of emissions sourced from peatlands increases 38%. Prohibiting intact and logged forest and peatland conversion to oil palm reduces emissions only 4% below BAU, because of continued uncontrolled fire. Protecting logged forests achieves greater carbon emissions reductions (21%) than protecting intact forests alone (9%) and is critical for mitigating carbon emissions. Extensive allocated leases constrain land management options, requiring trade-offs among oil palm production, carbon emissions mitigation, and maintaining community landholdings. PMID:22523241
Carlson, Kimberly M; Curran, Lisa M; Ratnasari, Dessy; Pittman, Alice M; Soares-Filho, Britaldo S; Asner, Gregory P; Trigg, Simon N; Gaveau, David A; Lawrence, Deborah; Rodrigues, Hermann O
Improved field emission performance of carbon nanotube by introducing copper metallic particles
NASA Astrophysics Data System (ADS)
To improve the field emission performance of carbon nanotubes (CNTs), a simple and low-cost method was adopted in this article. We introduced copper particles for decorating the CNTs so as to form copper particle-CNT composites. The composites were fabricated by electrophoretic deposition technique which produced copper metallic particles localized on the outer wall of CNTs and deposited them onto indium tin oxide (ITO) electrode. The results showed that the conductivity increased from 10-5 to 4 Î 10-5 S while the turn-on field was reduced from 3.4 to 2.2 V/?m. Moreover, the field emission current tended to be undiminished after continuous emission for 24 h. The reasons were summarized that introducing copper metallic particles to decorate CNTs could increase the surface roughness of the CNTs which was beneficial to field emission, restrain field emission current from saturating when the applied electric field was above the critical field. In addition, it could also improve the electrical contact by increasing the contact area between CNT and ITO electrode that was beneficial to the electron transport and avoided instable electron emission caused by thermal injury of CNTs.
Chen, Yiren; Jiang, Hong; Li, Dabing; Song, Hang; Li, Zhiming; Sun, Xiaojuan; Miao, Guoqing; Zhao, Haifeng
Stable Electron Field Emission afrom Opened-Tip Carbon Nanotube Bundles
NASA Astrophysics Data System (ADS)
Effective electron field emission from carbon nanotubes (CNTs) has been known for years but reliable commercial devices are still not available. Most reported works describe low emission threshold field (Eth) of CNTs and their device architectures. However, fundamental factors that determine stable emission from CNTs are still not clear. We previously reported that graphitic order of CNTs affects their emission stability [1]. Here, we found that both opened tip nanotubes and bundling, when introduced independently, can reduce Eth of CNTs and enhance the emission stability. The combined of both factors, i.e., opened tip nanotube bundles are shown to emit electron continuously > ten hours with notable stability. Theoretical simulation was conducted in supporting our explanation on these enhanced emission properties. SEM, TEM and Raman spectroscopy was conducted to characterize the as grown CNTs. Y. K. Yap acknowledges support from the Defense Advanced Research Projects Agency (DAAD17-03-C-0115, through Army Research Laboratory). [1]. Kayastha et al, Nanotechnology 18, 035206 (2007).
Pandey, Archana; Prasad, Abhishek; Moscatello, Jason; Khin Yap, Yoke
Improved field emission performance of carbon nanotube by introducing copper metallic particles
To improve the field emission performance of carbon nanotubes (CNTs), a simple and low-cost method was adopted in this article. We introduced copper particles for decorating the CNTs so as to form copper particle-CNT composites. The composites were fabricated by electrophoretic deposition technique which produced copper metallic particles localized on the outer wall of CNTs and deposited them onto indium tin oxide (ITO) electrode. The results showed that the conductivity increased from 10-5 to 4 Î 10-5 S while the turn-on field was reduced from 3.4 to 2.2 V/?m. Moreover, the field emission current tended to be undiminished after continuous emission for 24 h. The reasons were summarized that introducing copper metallic particles to decorate CNTs could increase the surface roughness of the CNTs which was beneficial to field emission, restrain field emission current from saturating when the applied electric field was above the critical field. In addition, it could also improve the electrical contact by increasing the contact area between CNT and ITO electrode that was beneficial to the electron transport and avoided instable electron emission caused by thermal injury of CNTs.
Energy Use and Carbon Dioxide Emissions from Cropland Production in the United States, 1990-2004
Changes in cropland production and management influence energy consumption and emissions of CO2 from fossil-fuel combustion. A method was developed to calculate on-site and off-site energy and CO2 emissions for cropping practices in the US at the county scale. Energy consumption and emissions occur on-site from the operation of farm machinery and occur off-site from the manufacture and transport of cropland production inputs, such as fertilizers, pesticides, and agricultural lime. Estimates of fossil-fuel consumption and associated CO2 emissions for cropping practices enable (a) the monitoring of energy and emissions with changes in land management, and (b) the calculation and balancing of regional and national carbon budgets. Results indicate on-site energy use and total energy use (i.e., the sum of on-site and off-site) on US croplands in 2004 ranged from 1.6-7.9 GJ ha-1 yr-1 and from 5.5-20.5 GJ ha-1 yr-1, respectively. On-site and total CO2 emissions in 2004 ranged from 23-176 kg C ha-1 yr-1 and from 91-365 kg C ha-1 yr-1, respectively. During the period of this analysis (1990-2004), national total energy consumption for crop production ranged from 1204-1297 PJ yr-1 (Petajoule = 1 1015 Joule) with associated total fossil CO2 emissions ranging from 22.0-23.2 Tg C yr-1 (Teragram = 1 1012 gram). The annual proportion of on-site CO2 to total CO2 emissions changed depending on the diversity of crops planted. Adoption of reduced tillage practices in the US from 1990 to 2004 resulted in a net emissions reduction of 2.4 Tg C.
West, Tristram O. [ORNL; Brandt, Craig C [ORNL; Marland, Gregg [ORNL; Nelson, Richard G [ORNL; Hellwinckel, Chad M [ORNL; De La Torre Ugarte, Daniel G [ORNL
Energy use and carbon dioxide emissions from cropland production in the United States, 1990-2004.
Changes in cropland production and management influence energy consumption and emissions of CO(2) from fossil-fuel combustion. A method was developed to calculate on-site and off-site energy and CO(2) emissions for cropping practices in the United States at the county scale. Energy consumption and emissions occur on-site from the operation of farm machinery and occur off-site from the manufacture and transport of cropland production inputs, such as fertilizers, pesticides, and agricultural lime. Estimates of fossil-fuel consumption and associated CO(2) emissions for cropping practices enable (i) the monitoring of energy and emissions with changes in land management and (ii) the calculation and balancing of regional and national carbon budgets. Results indicate on-site energy use and total energy use (i.e., the sum of on-site and off-site) on U.S. croplands in 2004 ranged from 1.6 to 7.9 GJ ha(-1) yr(-1) and from 5.5 to 20.5 GJ ha(-1) yr(-1), respectively. On-site and total CO(2) emissions in 2004 ranged from 23 to 176 kg C ha(-1) yr(-1) and from 91 to 365 kg C ha(-1) yr(-1), respectively. During the period of this analysis (1990-2004), national total energy consumption for crop production ranged from 1204 to 1297 PJ yr(-1) (Petajoule = 1 x 10(15) Joule) with associated total fossil CO(2) emissions ranging from 21.5 to 23.2 Tg C yr(-1) (Teragram = 1 x 10(12) gram). The annual proportion of on-site CO(2) to total CO(2) emissions changed depending on the diversity of crops planted. Adoption of reduced tillage practices in the United States from 1990 to 2004 resulted in a net fossil emissions reduction of 2.4 Tg C. PMID:19202012
Nelson, Richard G; Hellwinckel, Chad M; Brandt, Craig C; West, Tristram O; De La Torre Ugarte, Daniel G; Marland, Gregg
A Systems Approach to Reducing Institutional GHG Emissions
ERIC Educational Resources Information Center
Purpose: The purpose of this paper is to establish necessity and methods for considering greenhouse gas (GHG) mitigation policies at a system-level. The research emphasizes connecting narrowly focused GHG mitigation objectives (e.g. reduce single occupancy vehicle travel) with broader institutional objectives (e.g. growth in student population) toů
Williamson, Sean R.
Methane Production from Carbon Oxides Over Borohydride-Reduced Transition Metals.
National Technical Information Service (NTIS)
This study was undertaken to continue the examination of the utility of borohydride-reduced transition metals as catalysts for the hydrogenation of carbon oxides to produce synthetic fuels. While most related efforts deal only with carbon monoxide (the pr...
T. W. Russell
Freshwater greenhouse gas emissions and their implications on landscape level carbon balances in India
NASA Astrophysics Data System (ADS)
Methane (CH4) and carbon dioxide (CO2) emissions from global freshwaters are important sources of greenhouse gases to the atmosphere. It has been estimated that about 0.65 Pg of C (CO2 equiv.) yr-1 in the form of CH4 and 1.4 Pg C yr -1 in the form of CO2 is being emitted from global freshwaters. Therefore, including freshwater emissions in the greenhouse gas budgets in the national or global levels could significantly reduce the estimated land carbon sink, but present estimates suffer from lack of data, in particular from tropical freshwaters. Hence, we attempted to test the validity of the land carbon sink estimate in India, a tropical country with a large number of natural and man-made water bodies. We measured the CH4 and CO2 fluxes and surface water concentrations from a wide variety of inland freshwaters like lakes, ponds, rivers, reservoirs, open wells, canals and springs in three South Indian states, Tamil Nadu, Kerala and Andhra Pradesh. We observed that almost all of these freshwater systems emitted varied amounts of CH4 and a majority of them emitted CO2, similar to other tropical locations in South America. We extrapolated the measured fluxes for the whole of Indian inland waters by using the total area of different categories of inland waters in the national wetland atlas of India. By comparing our estimates of aquatic fluxes with the national greenhouse gas budget, we show that the land carbon sink of India is substantially overestimated. Thus, freshwater emissions are important components of greenhouse gas budgets on a landscape level and it is necessary to incorporate them in national and global greenhouse gas budgets to accurately quantify the land carbon sink.
Panneer Selvam, B.; Natchimuthu, S.; Arunachalam, L.; Bastviken, D.
Predicting ammonia and carbon dioxide emissions from carbon and nitrogen biodegradability during animal waste composting
During composting of livestock manure, transformations of organic matter result in gaseous emissions, which can harm the environment. Two experiments were done in enclosures to measure the fluxes of NH3, N2O, CO2, CH4 and H2O emitted by 8 heaps of compost representing the range of biodegradability of nitrogen and carbon in the livestock manure. The heaps were monitored for the
Jean-Marie Paillat; Paul Robin; MÚlynda Hassouna; Philippe Leterme
Limestone injection reduces SO2 and NO \\/SUB x\\/ emissions
The phases of Foster Wheeler's programs are presented by which the company developed a less complex low-NO \\/SUB x\\/ burner. Two phases involved assessing the potential of premixing limestone with coal to reduce SO2, and evaluating a new method of in-burner sorbent injection. Upper furnace injection of limestone was also evaluated by Conoco at the DuPont facility. The article reports
J. Vatsky; E. S. Schindler
Method and apparatus for reducing solvent luminescence background emissions
The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region. 6 figs.
Affleck, R.L.; Ambrose, W.P.; Demas, J.N.; Goodwin, P.M.; Johnson, M.E.; Keller, R.A.; Petty, J.T.; Schecker, J.A.; Wu, M.
Method and apparatus for reducing solvent luminescence background emissions
The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region.
Affleck, Rhett L. (Los Alamos, NM) [Los Alamos, NM; Ambrose, W. Patrick (Los Alamos, NM) [Los Alamos, NM; Demas, James N. (Charlottesville, VA) [Charlottesville, VA; Goodwin, Peter M. (Jemez Springs, NM) [Jemez Springs, NM; Johnson, Mitchell E. (Pittsburgh, PA) [Pittsburgh, PA; Keller, Richard A. (Los Alamos, NM) [Los Alamos, NM; Petty, Jeffrey T. (Los Alamos, NM) [Los Alamos, NM; Schecker, Jay A. (Santa Fe, NM) [Santa Fe, NM; Wu, Ming (Los Alamos, NM) [Los Alamos, NM
Carbon Emissions from Deforestation in the Brazilian Amazon Region
NASA Technical Reports Server (NTRS)
A simulation model based on satellite observations of monthly vegetation greenness from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2002. The NASA-CASA (Carnegie Ames Stanford Approach) model estimates of annual forest production were used for the first time as the basis to generate a prediction for the standing pool of carbon in above-ground biomass (AGB; gC/sq m) for forested areas of the Brazilian Amazon region. Plot-level measurements of the residence time of carbon in wood in Amazon forest from Malhi et al. (2006) were interpolated by inverse distance weighting algorithms and used with CASA to generate a new regional map of AGB. Data from the Brazilian PRODES (Estimativa do Desflorestamento da Amazonia) project were used to map deforested areas. Results show that net primary production (NPP) sinks for carbon varied between 4.25 Pg C/yr (1 Pg=10(exp 15)g) and 4.34 Pg C for the region and were highest across the eastern and northern Amazon areas, whereas deforestation sources of CO2 flux from decomposition of residual woody debris were higher and less seasonal in the central Amazon than in the eastern and southern areas. Increased woody debris from past deforestation events was predicted to alter the net ecosystem carbon balance of the Amazon region to generate annual CO2 source fluxes at least two times higher than previously predicted by CASA modeling studies. Variations in climate, land cover, and forest burning were predicted to release carbon at rates of 0.5 to 1 Pg C/yr from the Brazilian Amazon. When direct deforestation emissions of CO2 from forest burning of between 0.2 and 0.6 Pg C/yr in the Legal Amazon are overlooked in regional budgets, the year-to-year variations in this net biome flux may appear to be large, whereas our model results implies net biome fluxes had actually been relatively consistent from year to year during the period 2000-2002. This is the first study to use MODIS data to model all carbon pools (wood, leaf, root) dynamically in simulations of Amazon forest deforestation from clearing and burning of all kinds.
Potter, C.; Klooster, S.; Genovese, V.
Carbon emissions from deforestation in the Brazilian Amazon Region
NASA Astrophysics Data System (ADS)
A simulation model based on satellite observations of monthly vegetation greenness from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2002. The NASA-CASA (Carnegie Ames Stanford Approach) model estimates of annual forest production were used for the first time as the basis to generate a prediction for the standing pool of carbon in above-ground biomass (AGB; g C m-2) for forested areas of the Brazilian Amazon region. Plot-level measurements of the residence time of carbon in wood in Amazon forest from Malhi et al. (2006) were interpolated by inverse distance weighting algorithms and used with CASA to generate a new regional map of AGB. Data from the Brazilian PRODES (Estimativa do Desflorestamento da Amaz˘nia) project were used to map deforested areas. Results show that net primary production (NPP) sinks for carbon varied between 4.25 Pg C yr-1 (1 Pg{=}1015 g) and 4.34 Pg C for the region and were highest across the eastern and northern Amazon areas, whereas deforestation sources of CO2 flux from decomposition of residual woody debris were higher and less seasonal in the central Amazon than in the eastern and southern areas. Increased woody debris from past deforestation events was predicted to alter the net ecosystem carbon balance of the Amazon region to generate annual CO2 source fluxes at least two times higher than previously predicted by CASA modeling studies. Variations in climate, land cover, and forest burning were predicted to release carbon at rates of 0.5 to 1 Pg C yr-1 from the Brazilian Amazon. When direct deforestation emissions of CO2 from forest burning of between 0.2 and 0.6 Pg C yr-1 in the Legal Amazon are overlooked in regional budgets, the year-to-year variations in this net biome flux may appear to be large, whereas our model results implies net biome fluxes had actually been relatively consistent from year to year during the period 2000-2002. This is the first study to use MODIS data to model all carbon pools (wood, leaf, root) dynamically in simulations of Amazon forest deforestation from clearing and burning of all kinds.
Potter, C.; Klooster, S.; Genovese, V.
Reduction of black carbon aerosols in Tokyo: Comparison of real-time observations with emission estimates
NASA Astrophysics Data System (ADS)
Black carbon (BC) aerosols alter the radiation budget both directly (by absorbing solar visible radiation) and indirectly (by acting as cloud condensation nuclei) and cause adverse health effects. The absorbing efficiency and direct radiative effect of BC strongly depend on its mass concentration (MBC) and type of emission source. In the present study, we report measurements of MBC at the Research Center for Advanced Science and Technology (RCAST), located at the center of the urban boundary of Tokyo, using an EC-OC analyzer from 2003 to 2005 and a filter-based Continuous Soot Monitoring System (COSMOS) during 2007-2010. The results indicate that MBC have decreased significantly from 2.6 ?g m-3 to 0.5 ?g m-3 (ś80% reduction) between 2003 and 2010. Vehicular emissions are the dominant source of BC in Tokyo, and the observed reduction in MBC is mainly attributed to the stringent regulations of particulate matter exhaust from vehicles imposed by the Japanese government. In addition, this observation is also supported from emission estimates using diurnal-weekly variations of MBC in Tokyo and explains the observed reduction to within about 20%. This is the first clear evidence of a significant reduction in BC emissions in Tokyo and shows that measures taken to reduce BC emissions from traffic sources have a strong effect on air quality in a mega-city and also reduce the climate impact of traffic emissions. We highlight the importance of long-term and reliable measurements in detecting BC trends and for the validation and regulation of emission control measures in mega-cities.
Kondo, Y.; Ram, K.; Takegawa, N.; Sahu, L.; Morino, Y.; Liu, X.; Ohara, T.
Water-washable ink system reduces printers' hazardous emissions
Printing industry solvents contain large quantities of volatile organic compounds (VOCs), a major contributor to air pollution in that industry. Because most printing inks contain non-water-soluble petroleum, organic solvents have been necessary to clean presses using those inks. However, under proposed control technique guidelines for lithographic printers issued by the Environmental Protection Agency (EPA), printing-press wash solutions could contain no more than 30% VOCs. Deluxe Corp., a St. Paul, Minn.-based lithographic printer, recognized that stiffer emissions rules could mean harsh penalties for non-compliance and, in 1990, began developing a water-based press wash that would meet the guidelines. Deluxe last year introduced a 100% vegetable oil-based ink that becomes water-washable when exposed to the company's water-based press-wash solution. The solvent-free system eliminates VOCs and hazardous wastes associated with printing, contains no chemicals considered hazardous by EPA, uses no non-renewable resources, and works with existing printing equipment and processes. The system also eliminates water and soil contamination risks associated with laundering or landfilling solvent-saturated shop towels, saves money by eliminating the need to pay for hazardous waste disposal and provides relief to employees who complain about the strong odors of traditional press-wash solvents.
Kratch, K.
Process for reducing SOx emissions from catalytic cracking units
Reduction of SOx emissions from the regenerator associated with the fluidized catalytic cracking (Fcc) unit for converting hydrocarbon feedstocks into more valuable products is achieved by introducing into the fcc cycle one or more organic, aluminumcontaining compounds in dissolved form. In the catalytic cracking zone, the dissolved aluminum-containing compounds are converted to aluminum compounds that deposit relatively uniformly upon the catalyst particles. Also depositing upon the catalyst particles in the catalytic cracking zone are deactivating quantities of sulfur-containing coke. When such catalyst particles are introduced into the regenerator, wherein the sulfur-containing coke present on the catalyst surfaces is removed by combustion, thereby activating the catalyst particles, the SOx so produced reacts with the deposited aluminum compounds to form one or more stable, sulfur-aluminum oxidic compounds, thus desulfurizing the regenerator flue gas. Once deposited upon the catalyst particles, the aluminum compounds alternately react with the SOx compounds produced in the regenerator and then, by passage with the recycling catalyst particles through the catalytic cracking and steam stripping zones of the fcc unit, are converted to forms active for once again removing SOx compounds. Thus, just as the catalyst particles are alternately activated and deactivated for cracking hydrocarbons, the aluminum compounds dispersed on such catalyst particles undergo similar cyclical changes in activity with respect to SOx removal.
Mcarthur, D.P.
Optimizing grain yields reduces CH4 emissions from rice paddy fields.
Microbial production in anoxic wetland rice soils is a major source of atmospheric CH4 the most important non-CO2 greenhouse gas. Much higher CH4 emissions from well managed irrigated rice fields in the wet than in the dry season could not be explained by seasonal differences in temperature. We hypothesized that high CH4 emissions in the wet season are caused by low grain to biomass ratios. In a screenhouse experiment, removing spikelets to reduce the plants' capacity to store photosynthetically fixed C in grains increased CH4 emissions, presumably via extra C inputs to the soil. Unfavorable conditions for spikelet formation in the wet season may similarly explain high methane emissions. The observed relationship between reduced grain filling and CH4 emission provides opportunities to mitigate CH4 emissions by optimizing rice productivity. PMID:12189212
Denier Van Der Gon, H A C; Kropff, M J; Van Breemen, N; Wassmann, R; Lantin, R S; Aduna, E; Corton, T M; Van Laar, H H
Woody encroachment reduces nutrient limitation and promotes soil carbon sequestration
During the past century, the biomass of woody species has increased in many grassland and savanna ecosystems. As many of these species fix nitrogen symbiotically, they may alter not only soil nitrogen (N) conditions but also those of phosphorus (P). We studied the N-fixing shrub Dichrostachys cinerea in a mesic savanna in Zambia, quantifying its effects upon pools of soil N, P, and carbon (C), and availabilities of N and P. We also evaluated whether these effects induced feedbacks upon the growth of understory vegetation and encroaching shrubs. Dichrostachys cinerea shrubs increased total N and P pools, as well as resin-adsorbed N and soil extractable P in the top 10-cm soil. Shrubs and understory grasses differed in their foliar N and P concentrations along gradients of increasing encroachment, suggesting that they obtained these nutrients in different ways. Thus, grasses probably obtained them mainly from the surface upper soil layers, whereas the shrubs may acquire N through symbiotic fixation and probably obtain some of their P from deeper soil layers. The storage of soil C increased significantly under D.ácinerea and was apparently not limited by shortages of either N or P. We conclude that the shrub D.ácinerea does not create a negative feedback loop by inducing P-limiting conditions, probably because it can obtain P from deeper soil layers. Furthermore, C sequestration is not limited by a shortage of N, so that mesic savanna encroached by this species could represent a C sink for several decades. We studied the effects of woody encroachment on soil N, P, and C pools, and availabilities of N and P to Dichrostachys cinerea shrubs and to the understory vegetation. Both N and P pools in the soil increased along gradients of shrub age and cover, suggesting that N fixation by D.ácinerea did not reduce the P supply. This in turn suggests that continued growth and carbon sequestration in this mesic savanna ecosystems are unlikely to be constrained by nutrient limitation and could represent a C sink for several decades.
Blaser, Wilma J; Shanungu, Griffin K; Edwards, Peter J; Olde Venterink, Harry
Woody encroachment reduces nutrient limitation and promotes soil carbon sequestration.
During the past century, the biomass of woody species has increased in many grassland and savanna ecosystems. As many of these species fix nitrogen symbiotically, they may alter not only soil nitrogen (N) conditions but also those of phosphorus (P). We studied the N-fixing shrub Dichrostachys cinerea in a mesic savanna in Zambia, quantifying its effects upon pools of soil N, P, and carbon (C), and availabilities of N and P. We also evaluated whether these effects induced feedbacks upon the growth of understory vegetation and encroaching shrubs. Dichrostachys cinerea shrubs increased total N and P pools, as well as resin-adsorbed N and soil extractable P in the top 10-cm soil. Shrubs and understory grasses differed in their foliar N and P concentrations along gradients of increasing encroachment, suggesting that they obtained these nutrients in different ways. Thus, grasses probably obtained them mainly from the surface upper soil layers, whereas the shrubs may acquire N through symbiotic fixation and probably obtain some of their P from deeper soil layers. The storage of soil C increased significantly under D.ácinerea and was apparently not limited by shortages of either N or P. We conclude that the shrub D.ácinerea does not create a negative feedback loop by inducing P-limiting conditions, probably because it can obtain P from deeper soil layers. Furthermore, C sequestration is not limited by a shortage of N, so that mesic savanna encroached by this species could represent a C sink for several decades. We studied the effects of woody encroachment on soil N, P, and C pools, and availabilities of N and P to Dichrostachys cinerea shrubs and to the understory vegetation. Both N and P pools in the soil increased along gradients of shrub age and cover, suggesting that N fixation by D.ácinerea did not reduce the P supply. This in turn suggests that continued growth and carbon sequestration in this mesic savanna ecosystems are unlikely to be constrained by nutrient limitation and could represent a C sink for several decades. PMID:24834338
Blaser, Wilma J; Shanungu, Griffin K; Edwards, Peter J; Olde Venterink, Harry
Evaluation of Refrigerating and Air Conditioning Devices in Energy Cascade Systems under the Restriction of Carbon Dioxide Emissions
NASA Astrophysics Data System (ADS)
It is necessary to introduce energy cascade systems into the industrial sector in Japan to reduce carbon dioxide emissions. The aim of this study is to evaluate the refrigerating and air conditioning devices in cases of introducing both energy cascade systems and thermal recycling systems in industries located around urban areas. The authors have developed an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Limitation of carbon dioxide emissions results in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature one is shifted to refrigeration. It was found that increasing the amount of garbage combustor waste heat can reduce electric power for the turbo refrigerator by promoting waste heat driven ammonia absorption refrigerator.
Shimazaki, Yoichi; Akisawa, Atsushi; Kashiwagi, Takao
Emissions of carbon monoxide and carbon dioxide from uncompressed and pelletized biomass fuel burning in typical household stoves in China
NASA Astrophysics Data System (ADS)
Carbon dioxide (CO2) and carbon monoxide (CO) impact climate change and human health. The uncertainties in emissions inventories of CO2 and CO are primarily due to the large variation in measured emissions factors (EFs), especially to the lack of EFs from developing countries. China's goals of reducing CO2 emissions require a maximum utilization of biomass fuels. Pelletized biomass fuels are well suited for the residential biomass market, providing possibilities of more automated and optimized systems with higher modified combustion efficiency (MCE) and less products from incomplete combustion. However, EFs of CO2 and CO from pellet biomass fuels are seldom reported, and a comparison to conventional uncompressed biomass fuels has never been conducted. Therefore, the objectives of this study were to experimentally determine the CO2 and CO EFs from uncompressed biomass (i.e., firewood and crop residues) and biomass pellets (i.e., pine wood pellet and corn straw pellet) under real residential applications and to compare the influences of fuel properties and combustion conditions on CO2 and CO emissions from the two types of biomass fuels. For the uncompressed biomass examples, the CO2 and CO EFs were 1649.4 ▒ 35.2 g kg-1 and 47.8 ▒ 8.9 g kg-1, respectively, for firewood and 1503.2 ▒ 148.5 g kg-1 and 52.0 ▒ 14.2 g kg-1, respectively, for crop residues. For the pellet biomass fuel examples, the CO2 and CO EFs were 1708.0 ▒ 3.8 g kg-1 and 4.4 ▒ 2.4 g kg-1, respectively, for pellet pine and 1552.1 ▒ 16.3 g kg-1 and 17.9 ▒ 10.2 g kg-1, respectively, for pellet corn. In rural China areas during 2007, firewood and crop residue burning produced 721.7 and 23.4 million tons of CO2 and CO, respectively.
Wei, Wen; Zhang, Wei; Hu, Dan; Ou, Langbo; Tong, Yindong; Shen, Guofeng; Shen, Huizhong; Wang, Xuejun
Energy Taxation as a Policy Instrument to Reduce CO 2 Emissions: A Net Benefit Analysis
This study evaluates the costs and benefits of energy taxation as a policy instrument to conserve energy and reduce CO2 emissions. The study combines economic cost estimates generated with a CGE model and monetary estimates of environmental damages in a comprehensive cost\\/benefit framework. We find that optimal CO2 emissions reductions range from 5 to 38%, depending on different assumptions about
Roy Boyd; Kerry Krutilla; W. Kip Viscusi
Can fire regimes in savannas be managed to reduce greenhouse gas emissions: evidence from northern Australia?
Burning of savannas and grasslands consumes more than one third of the total annual biomass burning globally while in Australia, savanna burning comprises 2% to 4% of national greenhouse gas (GHG) emissions. This national significance of this has led to efforts to reduce savanna burning emissions by better managing the extensive fires that burn across northern Australia each year. The
Garry Cook; Fabienne Reisen; Jeremy Russell-Smith; Stefan Maier; Adam Liedloff; Jon Schatz; Cameron Yates; Felicity Watt
Options for reducing refrigerant emissions from supermarket systems. Final report, February-September 1994
The report was prepared to assist personnel responsible for the design, construction, and maintenance of retail food refrigeration equipment in making knowledgeable decisions regarding the implementation of refrigerant-emissions-reducing practices and technologies. It characterizes the design of typical supermarket refrigeration systems and focuses on why these types of systems have high rates of refrigerant emissions. Three case studies are provided of
Mobile laboratory measurements of black carbon, polycyclic aromatic hydrocarbons and other vehicle emissions in Mexico City
NASA Astrophysics Data System (ADS)
Black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) are of concern due to their effects on climate and health. The main goal of this research is to provide the first estimate of emissions of BC and particle-phase PAHs (PPAHs) from motor vehicles in Mexico City. The emissions of other pollutants including carbon monoxide (CO), oxides of nitrogen (NOx), volatile organic compounds (VOCs), and particulate matter of diameter 2.5 Ám and less (PM2.5) are also estimated. As a part of the Mexico City Metropolitan Area field campaign in April 2003 (MCMA-2003), a mobile laboratory was driven throughout the city. The laboratory was equipped with a comprehensive suite of gas and particle analyzers, including an aethalometer that measured BC and a photoionization aerosol sensor that measured PPAHs. While driving through traffic, the mobile lab is continuously sampling exhaust plumes from the vehicles around it. We have developed a method of automatically identifying exhaust plumes, which are then used as the basis for calculation of fleet-average emission factors. In the approximately 75 h of on-road sampling during the field campaign, we have identified ~30 000 exhaust measurement points that represent a variety of vehicle types and driving conditions. The large sample provides a basis for estimating fleet-average emission factors and thus the emission inventory. Motor vehicles in the Mexico City area are estimated to emit 1700▒200 metric tons BC, 57▒6 tons PPAHs, 1 190 000▒40 000 tons CO, 120 000▒3000 tons NOx, 202 000▒4000 tons VOCs, and 4400▒400 tons PM2.5 per year, not including cold start emissions. The estimates for CO, NOx, and PPAHs may be low by up to 10% due to the slower response time of analyzers used to measure these species. Compared to the government's official motor vehicle emission inventory for the year 2002, the estimates for CO, NOx, VOCs, and PM2.5 are 38% lower, 23% lower, 7% higher, and 26% higher, respectively. The distributions of emission factors of BC, PPAHs, and PM2.5 are highly skewed, i.e. asymmetric, while those for benzene, measured as a surrogate for total VOCs, and NOx are less skewed. As a result, the total emissions of BC, PPAHs, and PM2.5 could be reduced by approximately 50% if the highest 20% of data points were removed, but ''super polluters'' are less influential on overall NOx and VOC emissions.
Jiang, M.; Marr, L. C.; Dunlea, E. J.; Herndon, S. C.; Jayne, J. T.; Kolb, C. E.; Knighton, W. B.; Rogers, T. M.; Zavala, M.; Molina, L. T.; Molina, M. J.
Investigation of Technologies to Reduce Emissions of Methylene Chloride from Furniture Stripping Operations.
National Technical Information Service (NTIS)
This document describes the results of a project to investigate methods of reducing emissions of and the risk posed by methylene chloride (METH) emitted from furniture stripping facilities. METH is used in the stripping formulations used by these shops. T...
K. Wolf M. Morris
Accounting for Carbon Dioxide Emissions from Biomass Energy Combustion (released in AEO2010)
Carbon Dioxide (CO2) emissions from the combustion of biomass to produce energy are excluded from the energy-related CO2 emissions reported in Annual Energy Outlook 2010. According to current international convention, carbon released through biomass combustion is excluded from reported energy-related emissions. The release of carbon from biomass combustion is assumed to be balanced by the uptake of carbon when the feedstock is grown, resulting in zero net emissions over some period of time]. However, analysts have debated whether increased use of biomass energy may result in a decline in terrestrial carbon stocks, leading to a net positive release of carbon rather than the zero net release assumed by its exclusion from reported energy-related emissions.
Information Center
On-site denitrification beds could reduce indirect greenhouse gas emissions from agricultural drainage waters
NASA Astrophysics Data System (ADS)
Nitrate (NO3-) laden agricultural drainage waters are non-point sources of indirect nitrous oxide (N2O) emissions, which represent a significant fraction of total N2O emissions in the USA. On-site denitrification beds filled with woodchips were used to reduce NO3- under carbon rich anaerobic conditions. However, the anaerobic conditions may produce N2O and methane (CH4) to overcome the benefit of NO3- removal. We measured dissolved NO3-, N2O, and CH4 in influents and effluents of denitrification beds as well as soil surface N2O and CH4 fluxes above the bioreactors at two agricultural fields with corn-soybean rotation systems located in the upper Midwest of USA (Dundas and Claremont, Minnesota). Denitrification beds at both sites decrease NO3- from the drainage waters with an average rate of 5.0 g N m-3 d-1 in Dundas and 3.8 g N m-3 d-1 in Claremont. The surface fluxes of N2O and CH4 above the beds were similar to the fluxes measured from adjacent unfertilized fields. Dissolved CH4 in effluents was 38 times and 197 times greater than that in influents in Dundas and Claremont, respectively. Dissolved N2O in effluents was 40% less than that in influents at Dundas, but 15 times greater than that in influents in Claremont. The relationship between effluent to influent ratio of NO3- and hydraulic residence time (HRT) indicated that 50% of NO3- reduction requires 1.1 d in Dundas and 2.3 d in Claremont, although an average HRT was 2.1 d in Dundas and 0.6 d in Claremont. Balance of estimated global warming potential (GWP) indicated that denitrification bed in Claremont increased GWP by 138 g CO2 eq. ha-1 d-1, however, denitrification beds in Dundas reduced GWP by 151 g CO2 eq. ha-1 d-1. These results suggest that denitrification beds could mitigate indirect greenhouse gas emissions if hydraulic residence time is long enough, and denitrification process goes to completion, i.e., from NO3 to di-nitrogen.
Fujinuma, R.; Venterea, R. T.; Ranaivoson, A.; Moncrief, J.; Dittrich, M. A.
Gasoline-powered serial hybrid cars cause lower life cycle carbon emissions than battery cars
NASA Astrophysics Data System (ADS)
Battery cars powered by grid electricity promise reduced life cycle green house gas (GHG) emissions from the automotive sector. Such scenarios usually point to the much higher emissions from conventional, internal combustion engine cars. However, today's commercially available serial hybrid technology achieves the well known efficiency gains from regenerative breaking, lack of gearbox, and light weighting - even if the electricity is generated onboard, from conventional fuels. Here, we analyze emissions for commercially available, state-of the-art battery cars (e.g. Nissan Leaf) and those of commercially available serial hybrid cars (e.g., GM Volt, at same size and performance). Crucially, we find that serial hybrid cars driven on (fossil) gasoline cause fewer life cycle GHG emissions (126g CO2e per km) than battery cars driven on current US grid electricity (142g CO2e per km). We attribute this novel finding to the significant incremental life cycle emissions from battery cars from losses during grid transmission, battery dis-/charging, and larger batteries. We discuss crucial implications for strategic policy decisions towards a low carbon automotive sector as well as relative land intensity when powering cars by biofuel vs. bioelectricity.
Meinrenken, Christoph J.; Lackner, Klaus S.
Brown carbon in fresh and aged biomass burning emissions
NASA Astrophysics Data System (ADS)
To date, most climate forcing calculations treat black carbon (BC) and dust as the only particulate light absorbers. Numerous studies have shown that some organic aerosols (OA), referred to as brown carbon (BrC), also absorb light. BrC has been identified in biomass burning emissions; however, its light absorption properties are poorly constrained. Literature values of the imaginary part of the refractive indices of biomass burning OA (kOA) span two orders of magnitude. This variability, attributed to differences in fuel type and burning conditions, complicates the representation of biomass burning BrC in climate models. Proper accounting for BrC absorption in climate forcing calculations is of great importance. It can enhance the models' performance, bringing estimates of climate sensitivity to better agreement with observations. Here, we investigate the source of variability in absorptivity of biomass-burning OA observed in this study. We show that absorptivity is closely linked to OA volatility. Specifically, low-volatility organic compounds (LVOCs) are responsible for most of the light absorption, with effective kOA 1-2 orders of magnitude greater than the semi-volatile organic compounds (SVOCs). The effective kOA of biomass-burning emissions thus depends on the extent to which SVOCs partition to the condensed phase, which is sensitive to OA loading. kOA increases by a factor of 3-4 when the emissions are diluted from source concentrations (1-10 mg/m3) to atmospheric-like concentrations (1-10 ?g/m3), as the partitioning of SVOCs shifts towards the gas phase. More importantly, we demonstrate that the effective kOA depends largely on burn conditions, and not fuel type. Burns which produce high levels of BC emit OA that is more absorptive than burns which produce low levels of BC. The dependence of kOA on OA loading and burn conditions can be parameterized as a function of a single property of the emissions, namely the BC-to-OA ratio. Specifically, kOA at wavelength (lambda) of 550 nm increases linearly with the BC-to-OA ratio, while the spectral-dependence, w, where kČOA = kOA,550nm*(550/lambda)w, is inversely proportional to the BC-to-OA ratio. These correlations were determined by examining emissions from small scale laboratory burns of six globally relevant fuels (black spruce, ponderosa pine, hay, rice straw, saw grass, and wire grass), assuming that their behavior can be extrapolated to other biomass fuels. Experiments were conducted during the Fire Laboratory at Missoula Campaign (FLAME 4). The BC-to-OA ratios in the experiments were between 0.01 and 0.2. Aging of the emissions (photo-oxidation or dark ozonolysis) was performed in a smog chamber. To determine the dependence of absorptivity on volatility, the SVOCs were stripped from the condensed phase by heating the emissions to 250 C inside a thermodenuder. This allowed for constraining the optical properties of the low-volatility residue. kOA values were retrieved by performing optical closure, which combines Mie theory calculations with measurements of light absorption, and total and BC size distributions.
Saleh, R.; Robinson, E.; Tkacik, D. S.; Ahern, A.; Liu, S.; Aiken, A. C.; Sullivan, R. C.; Presto, A. A.; Dubey, M.; Donahue, N. M.; Robinson, A. L.
Reducing CO2-Emission by using Eco-Cements
NASA Astrophysics Data System (ADS)
CO2 concentration in the air is rising constantly. Globally, cement companies are emitting nearly two billion tonnes/year of CO2 (or around 6 to 7 % of the planet's total CO2 emissions) by producing portland cement clinker. At this pace, by 2025 the cement industry will be emitting CO2 at a rate of 3.5 billion tones/year causing enormous environmental damage (Shi et al., 2011; Janotka et al., 2012). At the dawn of the industrial revolution in the mid-eighteenth century the concentration of CO2 was at a level of ca. 280 ppm. 200 years later at the time of World War II the CO2 level had risen to 310 ppm what results in a rate of increase of 0,15 ppm per year for that period (Shi et al., 2011). In November 2011 the CO2 concentration reached a value of 391 ppm (NOAA Earth System Research Laboratory, 2011), a rise of ca. 81 ppm in 66 years and an increased rate of around 1,2 ppm/year respectively. In the same period cement production in tons of cement has multiplied by a factor of ca. 62 (Kelly & Oss, US Geological Survey, 2010). Thus new CO2-saving eco-cement types are gaining in importance. In these cement types the energy-consuming portland cement clinker is partially replaced by latent hydraulic additives such as blast furnace slag, fly ash or zeolite. These hydraulic additives do not need to be fired in the rotary furnace. They ony need to be pulverized to the required grain size and added to the ground portland cement clinker. Hence energy is saved by skipping the engery-consuming firing process, in addition there is no CO2-degassing as there is in the case of lime burning. Therefore a research project between Austria and Slovakia, funded by the EU (Project ENVIZEO), was initiated in 2010. The main goal of this project is to develop new CEM V eco-types of cements and certificate them for common usage. CEM V is a portland clinker saving cement kind that allows the reduction of clinker to a proportion of 40-64% for CEM V/A and 20-39% for CEM V/B respectively by the input of slag sands, puzzolanes and fly ash (according to standard EN 197-1). In this context four new CEM V kinds have been created, two Austrian types based on slag and fly ash, and two Slovak types, one based on slag and fly ash, the other on slag and natural pozzolana. The pozzolana consist of zeolite of clinoptilolite type that is gained from a Slovak deposit.
Voit, K.; Bergmeister, K.; Janotka, I.
Greenhouse gas emission accounting and management of low-carbon community.
As the major source of greenhouse gas (GHG) emission, cities have been under tremendous pressure of energy conservation and emission reduction for decades. Community is the main unit of urban housing, public facilities, transportation, and other properties of city's land use. The construction of low-carbon community is an important pathway to realize carbon emission mitigation in the context of rapid urbanization. Therefore, an efficient carbon accounting framework should be proposed for CO? emissions mitigation at a subcity level. Based on life-cycle analysis (LCA), a three-tier accounting framework for the carbon emissions of the community is put forward, including emissions from direct fossil fuel combustion, purchased energy (electricity, heat, and water), and supply chain emissions embodied in the consumption of goods. By compiling a detailed CO? emission inventory, the magnitude of carbon emissions and the mitigation potential in a typical high-quality community in Beijing are quantified within the accounting framework proposed. Results show that emissions from supply chain emissions embodied in the consumption of goods cannot be ignored. Specific suggestions are also provided for the urban decision makers to achieve the optimal resource allocation and further promotion of low-carbon communities. PMID:23251104
Song, Dan; Su, Meirong; Yang, Jin; Chen, Bin
Greenhouse Gas Emission Accounting and Management of Low-Carbon Community
As the major source of greenhouse gas (GHG) emission, cities have been under tremendous pressure of energy conservation and emission reduction for decades. Community is the main unit of urban housing, public facilities, transportation, and other properties of city's land use. The construction of low-carbon community is an important pathway to realize carbon emission mitigation in the context of rapid urbanization. Therefore, an efficient carbon accounting framework should be proposed for CO2 emissions mitigation at a subcity level. Based on life-cycle analysis (LCA), a three-tier accounting framework for the carbon emissions of the community is put forward, including emissions from direct fossil fuel combustion, purchased energy (electricity, heat, and water), and supply chain emissions embodied in the consumption of goods. By compiling a detailed CO2 emission inventory, the magnitude of carbon emissions and the mitigation potential in a typical high-quality community in Beijing are quantified within the accounting framework proposed. Results show that emissions from supply chain emissions embodied in the consumption of goods cannot be ignored. Specific suggestions are also provided for the urban decision makers to achieve the optimal resource allocation and further promotion of low-carbon communities.
Song, Dan; Su, Meirong; Yang, Jin; Chen, Bin
Analysis of Strategies for Reducing Multiple Emissions from Electric Power Plants with Advanced Technology
This analysis responds to a request of Senators James M. Jeffords and Joseph I. Lieberman. This report describes the impacts of technology improvements and other market-based opportunities on the costs of emissions reductions from electricity generators, including nitrogen oxides, sulfur dioxide, mercury, and carbon dioxide.
Information Center
Urban Fluxes Monitoring and Development of Planning Strategies to Reduce Ghg Emissions in AN European City
NASA Astrophysics Data System (ADS)
Cities and human settlements in general are a primary source of emissions that contribute to human-induced climate change. To investigate the impact of an urbanized area on urban metabolism components, an eddy covariance (EC) tower will be set up in a city (Sassari) located in the center of the Mediterranean basin (Sardinia, Italy). The EC tower, as well as a meteorological station and radiometers, will be set up to monitor energy, water, and carbon fluxes in the city center. A GHG emissions inventory will be also compiled to identify the main emission sources. In addition, a modeling framework will be used to study the impact of different urban planning strategies on carbon emission rates. The modeling framework consists of four models to analyze fluxes both at local and municipality scale: (i) a land surface model ACASA (Advanced Canopy-Atmosphere-Soil Algorithm, ACASA) to simulate the urban metabolism components at local scale; (ii) a Cellular Automata model to simulate the urban land-use dynamics in the near future (20-30 years); (iii) a transportation model to estimate the variation of the transportation network load, and (iv) the coupled model WRF-ACASA will be finally used to simulate the urban metabolism components at municipality scale. The participation of local stakeholders will allow the definition of future planning strategies with the aim to identify low carbon emissions strategies. The projects activities, methodologies applied, as well as the preliminary results will be reported here.
Marras, S.; Sirca, C.; Bellucco, V.; Falk, M.; Pyles, R. D.; Snyder, R. L.; Paw U, K.; Duce, P.; Blecic, I.; Trunfio, G. A.; Cecchini, A.; Spano, D.
Carbon emission and sequestration of urban turfgrass systems in Hong Kong.
Climate change is more than just a global issue. Locally released carbon dioxide may lead to a rise in global ambient temperature and influence the surrounding climate. Urban greenery may mitigate this as they can remove carbon dioxide by storing carbon in substrates and vegetation. On the other hand, urban greenery systems which are under intense management and maintenance may contribute to the emission of carbon dioxide or other greenhouse gases. The impact of urban greenery on carbon balance in major metropolitan areas thus remains controversial. We investigated the carbon footprints of urban turf operation and maintenance by conducting a research questionnaire on different Hong Kong turfs in 2012, and showed that turf maintenance contributed 0.17 to 0.63 kg Ce m(-2)y(-1) to carbon emissions. We also determined the carbon storage of turfs at 0.05 to 0.21 kg C m(-2) for aboveground grass biomass and 1.26 to 4.89 kg C m(-2) for soils (to 15 cm depth). We estimated that the carbon sink capacity of turfs could be offset by carbon emissions in 5-24 years under current management patterns, shifting from carbon sink to carbon source. Our study suggested that maintenance management played a key role in the carbon budget and footprint of urban greeneries. The environmental impact of turfgrass systems can be optimized by shifting away from empirically designed maintenance schedules towards rational ones based on carbon sink and emission principles. PMID:24365589
Kong, Ling; Shi, Zhengjun; Chu, L M
Options for reducing refrigerant emissions from supermarket systems. Final report, February-September 1994
The report was prepared to assist personnel responsible for the design, construction, and maintenance of retail food refrigeration equipment in making knowledgeable decisions regarding the implementation of refrigerant-emissions-reducing practices and technologies. It characterizes the design of typical supermarket refrigeration systems and focuses on why these types of systems have high rates of refrigerant emissions. Three case studies are provided of companies that have successfully implemented emission-reducing practices and technologies. The report discusses a variety of technical and procedural options that can be applied to existing systems and in new construction.
Troy, E.F.
[Stable carbon isotope of black carbon from typical emission sources in China].
Smoke particles from the three typical BC emission sources (biomass burning, household coal combustion, and vehicular exhaust) were collected and analyzed for stable carbon isotopes (delta13C) of black carbon (BC), total carbon (TC), as well as the original fuels. The results show that corn stalk (a typical C4 plant, -13.62 per thousand) has the highest delta13C(BC) value, and the average values for C3 plants, bituminous coals, and vehicle exhaust are -26.49 per thousand +/- 1.17 per thousand, -23.46 per thousand +/- 0.37 per thousand, and -25.17 per thousand +/- 0.40 per thousand, respectively. delta13C(BC) values from the three sources are similar to the corresponding fuels, and the ranges of these values are different from each other. Carbon fractionation occurs during the process of BC formation. delta13C(BC) for C4 plant (corn stalk) is lower than that of the fuel by 1.62 per thousand, while the values for C3 plants and coals are higher than that of the fuels by 0.63 per thousand and 0.52 per thousand, respectively. CTO-375 method, which is used to extract BC from TC, affects the stable carbon isotope of smokes from biomass burning to some extent (the difference between delta13C(BC) and delta13C(TC) is nearly 0.50 per thousand), but has little effect on fossil fuel smokes. This delta13C database for typical emission sources provides scientific information on BC source apportionment. PMID:22624354
Chen, Ying-Jun; Cai, Wei-Wei; Huang, Guo-Pei; Li, Jun; Zhang, Gan
India's cement industry: Productivity, energy efficiency and carbon emissions
Historical estimates of productivity growth in India's cement sector vary from indicating an improvement to a decline in the sector's productivity. The variance may be traced to the time period of study, source of data for analysis, and type of indices and econometric specifications used for reporting productivity growth. Analysis shows that in the twenty year period, 1973 to 1993, productivity in the aluminum sector increased by 0.8% per annum. An econometric analysis reveals that technical progress in India's cement sector has been biased towards the use of energy and capital, while it has been material and labor saving. The increase in productivity was mainly driven by a period of progress between 1983 and 1991 following partial decontrol of the cement sector in 1982. The authors examine the current changes in structure and energy efficiency in the sector. Their analysis shows that the Indian cement sector is moving towards world-best technology, which will result in fewer carbon emissions and more efficient energy use. However, substantial further energy savings and carbon reduction potentials still exist.
Schumacher, Katja; Sathaye, Jayant
Acoustic emission detection in carbon composite materials using Fiber Bragg Grating optical sensors
NASA Astrophysics Data System (ADS)
In light of ongoing efforts to reduce weight but maintain durability, designers have examined the use of carbon fiber reinforced polymer (CFRP) composite materials for a number of aerospace and civil structures. Along with this research has been the study of determining reliable sensing and monitoring capabilities to avoid catastrophic failure. Fiber Bragg Grating (FBG) sensors are known to carry several advantages in this area, one of which is their proven ability to detect acoustic emission (AE) Lamb waves in composite structures. AE is produced in these materials by failure mechanisms such as resin cracking, fiber debonding, fiber pullout and fiber breakage. In this study FBG sensors were attached to CFRP laminates to detect acoustic emission events. Also Felicity Ratio (FR) measurements were made as they accumulated damage. FR is obtained directly from the ratio of the stress level at the onset of significant emission versus the maximum prior stress at the same AE level. The main objective of this paper is to describe the results of acousto-optic experiments using FBG sensors and present it as a way of determining accumulated damage in a carbon composite structure.
Mabry, Nehemiah J.
Carbonization of biomass - an efficient tool to decrease the emission of CO2
NASA Astrophysics Data System (ADS)
The paper presents the results and analysis of biomass processing in order to provide the conditions for the most profitable use of the biomass in modern and efficient power generation systems with particular attention put on the decrease of the emission of carbon dioxide (CO2) and no need to develop carbon capture and storage plants. The promising concept of CO2 storage via the production of biochar and the advantages of its application as a promising carbon sink is also presented and the results are supported by authors' own experimental data. The idea enables the production of electricity, as well as (optionally) heat and cold from the thermal treatment of biomass with simultaneous storage of the CO2 in a stable and environmentally-friendly way. The key part of the process is run in a specially-designed reactor where the biomass is heated up in the absence of oxygen. The evolved volatile matter is used to produce heat/cold and electricity while the remaining solid product (almost completely dry residue) is sequestrated in soil. The results indicate that in order to reduce the emission of CO2 the biomass should rather be `cut and char' than just `cut and burn', particularly that the charred biomass may also become a significant source of nutrients for the plants after sequestration in soil.
Koby?ecki, Rafa?; ?cis?owska, Mariola; Bis, Zbigniew
Acoustic emission felicity ratio measurements in carbon composites laminates using fiber Bragg grating sensors
NASA Astrophysics Data System (ADS)
In light of ongoing efforts to reduce weight but maintain durability, designers have examined the use of carbon composite materials for a number of aerospace and civil structures. Along with this has been the study of reliable sensing and monitoring capabilities to avoid catastrophic failure. Fiber Bragg Grating (FBG) sensors are known to carry several advantages in this area one of which is their proven ability to detect acoustic emission (AE) lamb waves of various frequencies. AE is produced in these materials by failure mechanisms such as resin cracking, fiber debonding, fiber pullout and fiber breakage. With such activity there is a noticeable change in Felicity Ratio (FR) in relation to the increase of accumulated damage. FR is obtained directly from the ratio of the stress level at the onset of significant emission and the maximum prior stress at the same AE event. The main objective of this paper is to record the FRs of a carbon/epoxy laminate using FBG sensors and establish its trend as a method for determining accumulated damage in a carbon composite structure.
Mabry, Nehemiah; Banks, Curtis; Toutanji, Houssam; Seif, Mohamed
Future ocean increasingly transparent to low-frequency sound owing to carbon dioxide emissions
NASA Astrophysics Data System (ADS)
Low-frequency sound in the ocean is produced by natural phenomena such as rain, waves and marine life, as well as by human activities, such as the use of sonar systems, shipping and construction. Sea water absorbs sound mainly owing to the viscosity of the water and the presence of chemical constituents, such as magnesium sulphate, boric acid and carbonate ions. The concentration of dissolved chemicals absorbing sound near 1kHz depends on the pH of the ocean, which has declined as a result of increases in acidity due to anthropogenic emissions of carbon dioxide. Here we use a global ocean model forced with projected carbon dioxide emissions to predict regional changes in pH, and thus sound absorption, in the years 1800-2300. According to our projections, ocean pH could fall by up to 0.6 units by 2100. Sound absorption-in the range between ~100Hz and ~10kHz-could fall by up to 60% in the high latitudes and in areas of deep-water formation over the same time period. We predict that over the twenty-first century, chemical absorption of sound in this frequency range will nearly halve in some of the regions that experience significant radiated noise from industrial activity, such as the North Atlantic Ocean. We suggest that our forecast of reduced sound absorption in acoustic hotspots will help in identifying target regions for future monitoring.
Ilyina, Tatiana; Zeebe, Richard E.; Brewer, Peter G.
Getter Embedding Carbon Nanotube Cathode for Large-Area Field-Emission Display
NASA Astrophysics Data System (ADS)
We present a getter-embedding screen-printed carbon nanotube cathode made by embedding non-evaporable getter fine powders into a carbon nanotube paste. The composite have uniform field emission and sufficient adsorption speed, and is advantageous for in-situ pumping during bake-out as well as maintaining uniform vacuum levels in the large flat panel field emission displays.
Qian, Li; Liu, Liang; Fan, Shoushan; Qi, Jing; Chen, Xu; Hu, Yinfu; Wei, Xiuying; Zhou, Hongguo
A method to estimate the spatial distribution of transport carbon emissions in Shanghai
According to the fourth assessment report of IPCC (Intergovernmental Panel on Climate Change), global warming owns more than 90% to human activities. And quantification of human-induced CO2 emission at fine space and time resolution has a critical need in carbon cycle and climate change research. Carbon emission from urban traffic caused by burning fossil fuels is a key source in
Junkui Zhang; Junyan Zhao; Siqi Jia; Qi Li; Shuai Liu
Drivers on carbon dioxide emissions from the Scheldt river basin
NASA Astrophysics Data System (ADS)
Inland waters are a key component of the global carbon (C) cycle that transport organic and inorganic C from the terrestrial biosphere to the coastal ocean and emit CO2 to the atmosphere at a significant rate for global CO2 budgets. Yet, mechanisms underlying this CO2 emission to the atmosphere remain poorly understood and seldom modelled mechanistically. For this application a module describing the carbonate system and CO2 air-water exchange was added to the biogeochemical Seneque/Riverstrahler model describing transformation of C, N, P, Si occurring within hydrological networks. The model was applied to the human impacted Scheldt basin and the evolution of the partial pressure of CO2 (pCO2) and air-water CO2 flux was simulated for the year 1997 when data of dissolved inorganic carbon (DIC), total alkalinity (TA) and pCO2 are available for model validation. The model reproduces reasonably well the seasonal and spatial variations of the DIC, TA and pCO2 within the 5 main rivers of the Scheldt basin where data are available. At the annual level, the studied rivers act as major sources of CO2 to the atmosphere. Results show that the longitudinal variations of pCO2 are mainly controlled by the importance of air-water CO2 exchange. However, the choice of the parameterization of the gas transfer coefficient does not appear critical for this particular system. Biological activity also locally modulates the longitudinal variations of pCO2, while diffuse inputs from the watershed determine the initial conditions in the river without significantly altering the patterns observed from the upstream to the downstream. Both diffuse and punctual sources of C and TA are important drivers of the CO2 exchange in the river. In particular, model application evidences the sensitivity of the simulated CO2 fluxes to the description of human activities on the watershed.
Gypens, Nathalie; Passy, Paul; Garnier, Josette; Billen, Gilles; Silvestre, Marie; Borges, Alberto V.
Methane production from carbon oxides over borohydride reduced transition metals. II. Final report
This study was undertaken to continue the examination of the utility of borohydride-reduced transition metals as catalysts for the hydrogenation of carbon oxides to produce synthetic fuels. While most related efforts deal only with carbon monoxide (the predominant oxide in coal gasification processes), we have included carbon dioxide in our work. Work with copper, cobalt, nickel and palladium has resulted
Status review of NASA programs for reducing aircraft gas turbine engine emissions
NASA Technical Reports Server (NTRS)
Programs initiated by NASA to develop and demonstrate low emission advanced technology combustors for reducing aircraft gas turbine engine pollution are reviewed. Program goals are consistent with urban emission level requirements as specified by the U. S. Environmental Protection Agency and with upper atmosphere cruise emission levels as recommended by the U. S. Climatic Impact Assessment Program and National Research Council. Preliminary tests of advanced technology combustors indicate that significant reductions in all major pollutant emissions should be attainable in present generation aircraft gas turbine engines without adverse effects on fuel consumption. Preliminary test results from fundamental studies indicate that extremely low emission combustion systems may be possible for future generation jet aircraft. The emission reduction techniques currently being evaluated in these programs are described along with the results and a qualitative assessment of development difficulty.
Rudey, R. A.
Energy efficiency and carbon dioxide emissions reduction opportunities in the U.S. cement industry
This paper reports on an in-depth analysis of the U.S. cement industry, identifying cost-effective energy efficiency measures and potentials. The authors assess this industry at the aggregate level (Standard Industrial Classification 324), which includes establishments engaged in manufacturing hydraulic cements, including Portland, natural, masonry, and pozzolana when reviewing industry trends and when making international comparisons. Coal and coke are currently the primary fuels for the sector, supplanting the dominance of natural gas in the 1970s. Between 1970 and 1997, primary physical energy intensity for cement production (SIC 324) dropped 30%,from 7.9 GJ/t to 5.6 GJ/t, while carbon dioxide intensity due to fuel consumption (carbon dioxide emissions expressed in tons of carbon per ton cement) dropped 25%, from 0.16 tC/ton to 0.12 tC/ton. Carbon dioxide intensity due to fuel consumption and clinker calcination dropped 17%, from 0.29 tC/ton to 0.24 tC/ton. They examined 30 energy efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. They constructed an energy conservation supply curve for U.S. cement industry which found a total cost-effective reduction of 0.6 GJ/ton of cement consisting of measures having a simple payback period of 3 years or less. This is equivalent to potential energy savings of 11% of 1994 energy use for cement making and a savings of 5% of total 1994 carbon dioxide emissions by the U.S. cement industry. Assuming the increased production of blended cement in the U.S., as is common in many parts of the world, the technical potential for energy efficiency improvement would not change considerably. However, the cost-effective potential, would increase to 1.1 GJ/ton cement or 18% of total energy use, and carbon dioxide emissions would be reduced by 16%.
Martin, Nathan; Worrell, Ernst; Price, Lynn
Effectiveness of Diesel Oxidation Catalyst in Reducing HC and CO Emissions from Reactivity Controlled Compression Ignition
Reactivity Controlled Compression Ignition (RCCI) has been shown to allow for diesel-like or better brake thermal efficiency with significant reductions in nitrogen oxide (NOX) particulate matter (PM) emissions. Hydrocarbon (HC) and carbon monoxide (CO) emission levels, on the other hand, are similar to those of port fuel injected gasoline engines. The higher HC and CO emissions combined with the lower exhaust temperatures with RCCI operation present a challenge for current exhaust aftertreatments. The reduction of HC and CO emissions in a lean environment is typically achieved with an oxidation catalyst. In this work, several diesel oxidation catalysts (DOC) with different precious metal loadings were evaluated for effectiveness to control HC and CO emissions from RCCI combustion in a light-duty multi-cylinder engine operating on gasoline and diesel fuels. Each catalyst was evaluated in a steady-state engine operation with temperatures ranging from 160 to 260 C. A shift to a higher light-off temperature was observed during the RCCI operation. In addition to the steady-state experiments, the performances of the DOCs were evaluated during multi-mode engine operation by switching from diesel-like combustion at higher exhaust temperature and low HC/CO emissions to RCCI combustion at lower temperature and higher HC/CO emissions. High CO and HC emissions from RCCI generated an exotherm keeping the catalyst above the light-off temperature.
Prikhodko, Vitaly Y [ORNL; Curran, Scott [ORNL; Parks, II, James E [ORNL; Wagner, Robert M [ORNL
Carbon-doped SiO x nanowires with a large yield of white emission
NASA Astrophysics Data System (ADS)
The growth of SiO x nanowires (NWs) with intense white emission is reported. Due to carbon monoxide gas being used as a dopant precursor, carbon-doped under-stoichiometric silicon dioxide NWs are obtained. The doping of the NWs is studied by means of x-ray photoelectron spectroscopy, which allows to assess the presence of carbon atoms in the silicon oxide amorphous structure. The light emission properties are studied by means of cathodoluminescence spectroscopy, which shows three main emission bands set at 2.7 eV (blue), 2.3 eV (green) and 1.9 eV (red), resulting in the white emission.
Fabbri, Filippo; Rossi, Francesca; Negri, Marco; Tatti, Roberta; Aversa, Lucrezia; Chander Dhanabalan, Sathish; Verucchi, Roberto; Attolini, Giovanni; Salviati, Giancarlo
H. R. 804: A Bill to amend the Internal Revenue Code of 1986 to reduce emissions of carbon dioxide by imposing a tax on certain fuels based on their carbon content. Introduced in the House of Representatives, One Hundred Third Congress, First Session, February 3, 1993
H.R. 804 proposes the imposition of a carbon tax on primary fossil fuels. In general, Chapter 38 of the Internal Revenue Code of 1986 is to be amended by adding at the end thereof the following new subchapter: [open quotes]Subchapter E--Carbon Tax on Primary Fossil Fuels.[close quotes] Section 4691 will be concerned with the tax on coal; Section 4692 with the tax on petroleum; Section 4693 with the tax on natural gas; and Section 4694 will discuss inflation adjustments.
Not Available
Carbon emission tax and its impact on a developing country economy - A case study of India
Global climate change has become one of the most important of recent issues. It is estimated that roughly 60 percent of projected global climate change will be caused directly by the energy sector. Developing nations are the fastest growing greenhouse gas (GHG) emission sources. The restricted focus of the GHG problem to fossil fuels and carbon dioxide emissions in particular frightens the developing countries. Most studies on global climate change neglect the impact of proposed measures of carbon tax on the economies of the developing bloc. In this paper we examine the impacts of implementing a carbon emission tax on the economy of India using an input-output model. After discussing the economywide impacts of a carbon emission tax, possible measures for combating global climate change are examined. We also address the usefulness of energy-efficient technology to ameliorate carbon emissions.
Jayadevappa, R.; Chhatre, S.
Full Account of the Costs and Benefits of Reducing CO2 Emissions in Transport
Among economists and policy makers more general, the fuel efficiency standard for cars and the fuel tax have been the subject of extensive debate. The major benefits of stricter fuel efficiency standards and higher fuel taxes are the reduction of Greenhouse gas emissions and the reduced oil dependence. The major costs are the increased production cost, the reduced comfort and
Stef Proost
Assessing the potential of hybrid energy technology to reduce exhaust emissions from global shipping
The combination of a prime mover and an energy storage device for reduction of fuel consumption has successfully been used in automotive industry. The shipping industry has utilised this for conventional submarines. The potential of a load levelling strategy through use of a hybrid batteryľdieselľelectric propulsion system is investigated. The goal is to reduce exhaust gas emissions by reducing fuel
Eleftherios K. Dedes; Dominic A. Hudson; Stephen R. Turnock
Emission factors of PAHs, methoxyphenols, levoglucosan, elemental carbon and organic carbon from simulated wheat and Kentucky bluegrass stubble burns
NASA Astrophysics Data System (ADS)
Emission factors (EFs) of pollutants from post-harvest agricultural burning are required for predicting downwind impacts of smoke and inventorying emissions. EFs of polycyclic aromatic hydrocarbons (PAH), methoxyphenols (MP), levoglucosan (LG), elemental carbon (EC) and organic carbon (OC) from wheat and Kentucky bluegrass (KBG) stubble burning were quantified in a US EPA test burn facility. The PAH and MP EFs for combined solid+gas phases are 17▒8.2 mg kg -1 and 79▒36 mg kg -1, respectively, for wheat and 21▒15 mg kg -1 and 35▒24 mg kg -1, respectively, for KBG. LG, particulate EC and artifact-corrected OC EFs are 150▒130 mg kg -1, 0.35▒0.16 g kg -1 and 1.9▒1.1 g kg -1, respectively, for wheat and 350▒510 mg kg -1, 0.63▒0.056 g kg -1 and 6.9▒0.85 g kg -1, respectively, for KBG. Positive artifacts associated with OC sampling were evaluated and remedied with a two-filter system. EC and OC accounted for almost two-thirds of PM 2.5 mass, while LG accounted for just under 3% of the PM 2.5 mass. Since EFs of these pollutants generally decreased with increasing combustion efficiency (CE), identifying and implementing methods of increasing the CEs of burns would help reduce their emissions from agricultural field burning. PAH, OC and EC EFs are comparable to other similar studies reported in literature. MP EFs appear dependent on the stubble type and are lower than the EFs for hard and softwoods reported in literature, possibly due to the lower lignin content in wheat and KBG.
Dhammapala, Ranil; Claiborn, Candis; Jimenez, Jorge; Corkill, Jeffrey; Gullett, Brian; Simpson, Christopher; Paulsen, Michael
The impact of electric passenger transport technology under an economy-wide climate policy in the United States: Carbon dioxide emissions, coal use, and carbon dioxide capture and storage
Plug-in hybrid electric vehicles (PHEVs) have the potential to be an economic means of reducing direct (or tailpipe) carbon dioxide (CO2) emissions from the transportation sector. However, without a climate policy that places a limit on CO2 emissions from the electric generation sector, the net impact of widespread deployment of PHEVs on overall U.S. CO2 emissions is not as clear.
Marshall A. Wise; G. Page Kyle; James J. Dooley; Son H. Kim
Oxidized and reduced biogenic nitrogen compound emissions into the rural troposphere: Characterization and modeling
NASA Astrophysics Data System (ADS)
Using a dynamic flow-through chamber technique in conjunction with a state-of-the-art mobile laboratory, this research attempts to characterize and model oxidized and reduced biogenic nitrogen compound emissions into the rural troposphere. Nitrogen compound emissions are known to have profound effects on air quality. Consequences associated with increased emissions of oxidized and reduced nitrogen species are known to be increased tropospheric ozone production, fine particulate aerosol production, nitrate contamination of drinking water, eutrophication and acidification of soil and water bodies. It is well recognized that soil emissions can contribute a substantial percent of the total inventory for both the oxidized and reduced species, but great uncertainty still exists in this inventory. A controlled experiment involving the application of municipal waste biosolids to agricultural soils was shown to enhance NO emissions. A more detailed analysis throughout several seasons found the nitric oxide emissions from biosolid amended soils to have a strong temperature dependence and that their source strength is much larger relative to soils amended with chemically derived fertilizers. Emissions of nitric oxide from biosolid amended soils were modeled using the MultiScale Air Quality Simulation Platform (MAQSIP). Results from this model indicated that ozone concentrations can decrease by approximately 12% (in the evening) and increase by approximately 2% (during the daylight hours) when these biosolid amended soils are taken into consideration in the land use database. Emissions of ammonia from soils amended with swine waste effluent were also measured and modeled. This study revealed that while the average source strength of ammonia from soils is significantly smaller than that of the lagoons, the much larger surface area of the soils causes them to also be an important emissions source. A fundamental mechanistic mass transfer model is presented and discussed in terms of its applicability for estimating NH3 flux and was found to be an effective predictor of the NH3 emissions for time periods immediately following slurry application.
Roelle, Paul Andrew
High performance bulk metallic glass/carbon nanotube composite cathodes for electron field emission
We report the preparation of new nanocomposites based on a combination of bulk metallic glass and carbon nanotubes for electron field emission applications. The use of bulk metallic glass as the matrix ensures high electrical and thermal conductivity, high thermal stability, and ease of processing, whilst the well dispersed carbon nanotubes act as highly efficient electron emitters. These advantages, alongside excellent electron emission properties, make these composites one of the best reported options for electron emission applications to date.
Hojati-Talemi, Pejman [Department of Materials Engineering, Monash University, Clayton, Vic 3800 (Australia); Mawson Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia); Gibson, Mark A. [Process Science and Engineering, Commonwealth Scientific and Industrial Research Organisation, Clayton, Vic 3168 (Australia); East, Daniel; Simon, George P. [Department of Materials Engineering, Monash University, Clayton, Vic 3800 (Australia)
Detection of reduced carbon in basalt using Raman spectroscopy: a signpost to habitat on Mars
NASA Astrophysics Data System (ADS)
In the search for evidence of the environmental history of the Martian surface, and the possibility of life at some stage in the planet's history, a key component is reduced carbon. Carbon is available to the surface environment through meteoritic infall [1] and erosion of abundant volcanic rocks which contain magmatic carbon [2][3], in addition to the possibility of some biogenic carbonaceous matter. However, reduced carbon has not yet been detected by a range of missions to Mars. Carbonate minerals, containing carbon in inorganic oxidized form, have been recorded [4], which together with carbon dioxide in the Martian atmosphere and magmatic carbon in Martian meteorites provide evidence for a carbon cycle on Mars [5][6]. The mobility of carbon on Mars is also evident in fracture-bound carbon in the Nakhla meteorite, derived from Martian basalt [7] [8]. Basalts are widespread on Mars, so are readily accessible for sampling and analysis. Basalt-hosted carbon could have a relationship to life in both a consequential or causative manner. Basalt could incorporate carbon from organic matter disseminated in sediments through which the basaltic magma passed. It is even possible that basalt could concentrate carbon scavenged from sediments into carbon-rich structures. Alternatively, basalt could act as a feedstock of carbon to provide biomass for colonizing microbes. In this way, the discovery of carbon in (Martian) basalt could be regarded as a signpost to habitat, i.e. the identification of carbon is a key aspect of the strategy for targeting where evidence of life should be sought. The ExoMars mission, currently intended to fly in 2018, includes a Raman spectroscopy instrument, whose targets for detection include reduced carbon. We report here the study of an analogue for the carbon-bearing Nakhla meteorite, representing nearsurface Martian crust, using Raman spectroscopy and other techniques to demonstrate the potential to detect the reduced carbon therein. The analogue is a terrestrial basalt containing traces of reduced carbon in cross-cutting fractures.
Harris, L. V.; Hutchinson, I. B.; Parnell, J.; Ingley, R.; Edwards, H. G. M.
Enhancement of the field emission of carbon nanotubes straightened by application of argon ion irradiation
The field emission properties of carbon nanotubes (CNTs) were enhanced by argon ion irradiation. Argon irradiation treatment led to an enhancement in the emission properties of CNTs which showed a decrease in turn-on field and an increase in total emission current after the treatment. The irradiation treatment permanently straightened as-grown curly CNTs, and, as a result, the local electric field
Do-Hyung Kim; Hoon-Sik Jang; Chang-Duk Kim; Dong-Soo Cho; Hee-Dong Kang; Hyeong-Rag Lee
Carbon emissions from cities and urban regions at multiple levels (Invited)
NASA Astrophysics Data System (ADS)
The role of urban areas in global carbon emissions is expected to be significant and thus crucial for the global climate change mitigation. Accordingly, in this paper, consolidate and present the existing knowledge and information on the urban carbon emissions at global, regional and city levels. This is built on a consolidated knowledge from authorĺs organized and co-edited special issue in Energy Policy Journal titled Carbon Emissions and Carbon Management in Cities published in 2010, other of authorĺs own work in China, Thailand and North-East Asian cities, and the existing literatures on cities. In particular, we present and clarify the contribution of urban areas in the global and respective regional CO2 emissions and the CO2 emissions from the global cities including their inter-comparisons. In those discussions, we present the trends and patterns of CO2 emissions from cities and highlight the points of caution and uncertainties in CO2 estimation imposed by the definitions of urban areas and cities, the scope and approach of estimations, and the methodological limitations. We will pay a special attention to the carbon attribution challenges since urban area is essentially an open system with intense interactions outside its physical boundaries. Their responsibilities for carbon emissions and mitigation vary depending on the choice of the system boundary of urban activities and how carbon emissions are attributed. We show example of such phenomenon quantitatively thorough a case study of Tokyo.
Dhakal, S.
Renal carbonic anhydrase inhibition reduces high altitude sleep periodic breathing
The efficacy of carbonic anhydrase (CA) inhibitors in amelioration of periodic breathing during sleep at high altitude is not fully understood, Although CA is present in a number oftissues, we hypothesized that selective renal CA inhibition without physiologically important inhibition of other tissue CA, may be sufficient alone by its generation of a mild metabolic acidosis to stimulate ventilation and
Erik R. Swenson; Kim L. Leatham; Robert C. Roach; Robert B. Schoene; William J. Mills; Peter H. Hackett
A fast method for updating global fossil fuel carbon dioxide emissions
NASA Astrophysics Data System (ADS)
We provide a fast and efficient method for calculating global annual mean carbon dioxide emissions from the combustion of fossil fuels by combining data from an established data set with BP annual statistics. Using this method it is possible to retrieve an updated estimate of global CO2 emissions six months after the actual emissions occurred. Using this data set we find that atmospheric carbon dioxide emissions have increased by over 40% from 1990 to 2008 with an annual average increase of 3.7% over the five-year period 2003-2007. In 2008 the growth rate in the fossil fuel carbon dioxide emissions was smaller than in the preceding five years, but it was still over 2%. Global mean carbon dioxide emissions in 2008 were 8.8 GtC yr-1. For the latter part of the last century emissions of carbon dioxide have been greater from oil than from coal. However during the last few years this situation has changed. The recent strong increase in fossil fuel CO2 emissions is mainly driven by an increase in emissions from coal, whereas emissions from oil and gas to a large degree follow the trend from the 1990s.
Myhre, G.; AlterskjŠr, K.; Lowe, D.
Organically treated biochar increases plant production and reduces N2O emissions: mechanistic insights by 15N tracing
NASA Astrophysics Data System (ADS)
Pyrogenic carbon (biochar) offers considerable potential for carbon capture and soil storage (CCSS) compared to other, less recalcitrant soil-C additives. Recent meta-analysis demonstrated that it can significantly reduce agricultural N2O emissions. Freshly produced biochars, however, do not always have yield-improving effects, i.e. there is no immediate economic incentive for using it. Hence, combining biochar with organic nutrient-rich amendments may be a promising agricultural strategy to accelerate CCSS, but it is unclear if biochar still reduces N2O emissions, in particular when it may act as nutrient carrier. We explored the potential of biochar to improve the GHG-cost/yield ratio and thereby its socio-economic value as soil amendment in two subsequent studies under controlled conditions: (1) A proof-of-concept study where the effects of untreated biochar were compared to those of co-composted biochar combined with stepwise improved nutritional regimes (+/- compost; +/- mineral-N application), and (2) a 15N-labeling-tracing study to unravel N exchange on biochar particles and N2O production and reduction mechanisms. Both studies were carried out in nutrient-poor sandy soils, the most likely initial target soils for biochar-CCSS strategies. While the untreated biochar reduced plant growth under N-limiting conditions, or at best did not reduce it, the co-composted biochar always significantly stimulated plant growth. The relative stimulation was largest with the lowest nutrient additions (305% versus 61% of control with untreated biochar). Electro-ultra-filtration analyses revealed that the co-composted but not the untreated biochar carried considerable amounts of easily extractable as well as more strongly sorbed plant nutrients, in particular nitrate and phosphorus. The subsequent 15N labelling-tracing study revealed that the co-composted biochar still (i) acted as a mineral-N exchange site for nitrate and ammonium despite its N-preloading, (ii) reduced N2O emissions significantly, although it carried dissolved organic carbon and nitrate as prerequisites for denitrification; and that it thus (iii) significantly improved the GHG-cost/yield ratio of plant production. Our results therefore encourage further investigations on strategies where nutrient-rich agricultural waste streams are combined with biochar post-treatment. Cascading use of biochar in agriculture may have the potential to evolve into a key CCSS technology to turn agriculture from being part of the problem into being part of the solution.
Kammann, Claudia; Messerschmidt, Nicole; Clough, Tim; Schmidt, Hans-Peter; Marhan, Sven; Koyro, Hans-Werner; Steffens, Diedrich; MŘller, Christoph
Biomass collapse and carbon emissions from forest fragmentation in the Brazilian Amazon
NASA Astrophysics Data System (ADS)
Forest fragmentation due to deforestation is one of the major causes of forest degradation in the Amazon. Biomass collapse near forest edges, especially within 100 m, alters aboveground biomass and has potentially important implications for carbon emissions in the region. This phenomenon is tightly linked to spatial and temporal dynamics of forest edges in a landscape. However, the potential biomass loss and carbon emissions from forest edges and these spatiotemporal changes have never been estimated for actual landscapes in the Amazon. We conducted a deep temporal analysis of Rond˘nia, southwestern Brazilian Amazonia, using six Landsat path-row scenes covering the 1985-2008 time period to estimate annual biomass loss and associated carbon emissions within 100 m of forest edges. Annual edge biomass loss averaged 9.1% of the biomass loss from deforestation during the study period, whereas average annual edge-related carbon emissions from biomass loss were 6.0% of deforestation-derived carbon emissions. However, because many edges were subsequently deforested during the 24 year study period, actual unaccounted for edge-related carbon emissions during the 1985-2008 period, calculated from edges of all ages extant on the landscape in 2008, amounted to 3.6% of that attributed to all deforestation-derived carbon fluxes for this time interval. Biomass loss and carbon emissions are highly influenced by the extent and age of edge-affected forests. Large annual contributions of biomass loss and carbon emissions were found from active deforestation regions with young edges, whereas regions dominated by older edges had lower biomass loss and carbon emissions from edges.
Numata, Izaya; Cochrane, Mark A.; Roberts, Dar A.; Soares, JoŃO. V.; Souza, Carlos M.; Sales, Marcio H.
Carbon dioxide emissions under different soil tillage systems in mechanically harvested sugarcane
NASA Astrophysics Data System (ADS)
Soil tillage and other methods of soil management may influence CO2 emissions because they accelerate the mineralization of organic carbon in the soil. This study aimed to quantify the CO2 emissions under conventional tillage (CT), minimum tillage (MT) and reduced tillage (RT) during the renovation of sugarcane fields in southern Brazil. The experiment was performed on an Oxisol in the sugarcane-planting area with mechanical harvesting. An undisturbed or no-till (NT) plot was left as a control treatment. The CO2 emissions results indicated a significant interaction (p < 0.001) between tillage method and time after tillage. By quantifying the accumulated emissions over the 44 days after soil tillage, we observed that tillage-induced emissions were higher after the CT system than the RT and MT systems, reaching 350.09 g m-2 of CO2 in CT, and 51.7 and 5.5 g m-2 of CO2 in RT and MT respectively. The amount of C lost in the form of CO2 due to soil tillage practices was significant and comparable to the estimated value of potential annual C accumulation resulting from changes in the harvesting system in Brazil from burning of plant residues to the adoption of green cane harvesting. The CO2 emissions in the CT system could respond to a loss of 80% of the potential soil C accumulated over one year as result of the adoption of mechanized sugarcane harvesting. Meanwhile, soil tillage during the renewal of the sugar plantation using RT and MT methods would result in low impact, with losses of 12% and 2% of the C that could potentially be accumulated during a one year period.
Silva-Olaya, A. M.; Cerri, C. E. P.; La Scala, N., Jr.; Dias, C. T. S.; Cerri, C. C.
The potential for Bus Rapid Transit to reduce transportation-related CO2 emissions
This article examines Bus Rapid Transit (BRT) as a near-term strategy for reducing CO2 emissions in a typical medium-sized U.S. city. The paper compares the expected CO2 emissions from three scenarios to meet the cityĺs growth in work trips by 2011: a no-build option that relies upon private automobiles and a diesel bus fleet; building a light rail (LRT) system;
Willam Vincent; Lisa Callaghan Jerram
Increasing leaf temperature reduces the suppression of isoprene emission by elevated CO2 concentration.
Including algorithms to account for the suppression of isoprene emission by elevated CO2 concentration affects estimates of global isoprene emission for future climate change scenarios. In this study, leaf-level measurements of isoprene emission were made to determine the short-term interactive effect of leaf temperature and CO2 concentration. For both greenhouse plants and plants grown under field conditions, the suppression of isoprene emission was reduced by increasing leaf temperature. For each of the four different tree species investigated, aspen (Populus tremuloides Michx.), cottonwood (Populus deltoides W. Bartram ex Marshall), red oak (Quercus rubra L.), and tundra dwarf willow (Salix pulchra Cham.), the suppression of isoprene by elevated CO2 was eliminated at increased temperature, and the maximum temperature where suppression was observed ranged from 25 to 35░C. Hypotheses proposed to explain the short-term suppression of isoprene emission by increased CO2 concentration were tested against this observation. Hypotheses related to cofactors in the methylerythritol phosphate (MEP) pathway were consistent with reduced suppression at elevated leaf temperature. Also, reduced solubility of CO2 with increased temperature can explain the reduced suppression for the phosphoenolpyruvate (PEP) carboxylase competition hypothesis. Some global models of isoprene emission include the short-term suppression effect, and should be modified to include the observed interaction. If these results are consistent at longer timescales, there are implications for predicting future global isoprene emission budgets and the reduced suppression at increased temperature could explain some of the variable responses observed in long-term CO2 exposure experiments. PMID:24614154
Potosnak, Mark J; Lestourgeon, Lauren; Nunez, Othon
Energy Recovery from End-of-Life Tyres: Untapped Possibility to Reduce CO2 Emissions
NASA Astrophysics Data System (ADS)
In this paper the possibility to reduce CO2 emissions by energy recovery from waste tyres is discussed. The objective of the study is to analyze the end-of-life tyre market in Latvia, to assess the amount of used tyres available and to calculate the potential reduction of CO2 emissions by energy recovery from tyres in mineral products industry. Calculation results show that an improved collection and combustion of end-of-life tyres in the cement industry can save up to 17% of the present CO2 emissions in the mineral products industry.
Dzene, Ilze; Rochas, Claudio; Blumberga, Dagnija; Rosa, Marika; Erdmanis, Andris
Reducing nitrous oxide emissions to mitigate climate change and protect the ozone layer.
Reducing nitrous oxide (N2O) emissions offers the combined benefits of mitigating climate change and protecting the ozone layer. This study estimates historical and future N2O emissions and explores the mitigation potential for China's chemical industry. The results show that (1) from 1990 to 2012, industrial N2O emissions in China grew by some 37-fold from 5.07 to 174 Gg (N2O), with total accumulated emissions of 1.26 Tg, and (2) from 2012 to 2020, the projected emissions are expected to continue growing rapidly from 174 to 561 Gg under current policies and assuming no additional mitigation measures. The total accumulated mitigation potential for this forecast period is about 1.54 Tg, the equivalent of reducing all the 2011 greenhouse gases from Australia or halocarbon ozone-depleting substances from China. Adipic acid production, the major industrial emission source, contributes nearly 80% of the industrial N2O emissions, and represents about 96.2% of the industrial mitigation potential. However, the mitigation will not happen without implementing effective policies and regulatory programs. PMID:24749524
Li, Li; Xu, Jianhua; Hu, Jianxin; Han, Jiarui
Reducing Our Carbon Footprint, A Low Energy House
How well can we assess and improve building energy performance in California homes? How much energyŚand carbonŚdo homes use in other parts of the world? Rick Diamond, deputy group leader of the Ber... How well can we assess and improve building energy performance in California homes? How much energyŚand carbonŚdo homes use in other parts of the world? Rick Diamond, deputy group leader of the Berkeley Lab Energy Performance of Buildings Group, discusses change, global solutions, and the stories of three houses in Berkeley, Kabul (Afghanistan), and Washington, D.C. Diamond, who is also a senior advisor at the California Institute for Energy and Environment, investigates user interactions with the built environment for improved building energy performance. The group has studied a wide range of issues related to energy use in housing, including duct system efficiency, user behavior, and infiltration and ventilation measurements. His talk was presented September 17, 2007.
Reducing Our Carbon Footprint, A Low Energy House
How well can we assess and improve building energy performance in California homes? How much energy?and carbon?do homes use in other parts of the world? Rick Diamond, deputy group leader of the Ber... How well can we assess and improve building energy performance in California homes? How much energy?and carbon?do homes use in other parts of the world? Rick Diamond, deputy group leader of the Berkeley Lab Energy Performance of Buildings Group, discusses change, global solutions, and the stories of three houses in Berkeley, Kabul (Afghanistan), and Washington, D.C. Diamond, who is also a senior advisor at the California Institute for Energy and Environment, investigates user interactions with the built environment for improved building energy performance. The group has studied a wide range of issues related to energy use in housing, including duct system efficiency, user behavior, and infiltration and ventilation measurements. His talk was presented September 17, 2007.
Reducing Our Carbon Footprint, A Low Energy House
How well can we assess and improve building energy performance in California homes? How much energyŚand carbonŚdo homes use in other parts of the world? Rick Diamond, deputy group leader of the Ber... How well can we assess and improve building energy performance in California homes? How much energyŚand carbonŚdo homes use in other parts of the world? Rick Diamond, deputy group leader of the Berkeley Lab Energy Performance of Buildings Group, discusses change, global solutions, and the stories of three houses in Berkeley, Kabul (Afghanistan), and Washington, D.C. Diamond, who is also a senior advisor at the California Institute for Energy and Environment, investigates user interactions with the built environment for improved building energy performance. The group has studied a wide range of issues related to energy use in housing, including duct system efficiency, user behavior, and infiltration and ventilation measurements. His talk was presented September 17, 2007.
Development of a low-carbon product design system based on embedded GHG emissions
The GHG emissions of a product throughout its life cycle must be estimated, with problematic parts and\\/or materials identified to reduce greenhouse gas (GHG) emissions by the product. Products are made of parts; thus, the amount of GHG emissions of a product depends on the GHG emissions of the individual parts. Parts suitable for product specification are chosen to form
Jong-Sung Song; Kun-Mo Lee
Modern biofuels life-cycle effects on black carbon emissions and impacts
NASA Astrophysics Data System (ADS)
The rapid growth of modern biofuels production (primarily ethanol) contributes to increased black carbon and co-pollutant emissions, particularly due to the field burning of agriculture wastes and the indirect land use impacts of forest clearing. U.S. bioenergy policy has already mandated life-cycle emissions thresholds for greenhouse gases from biofuels but there is still a need to incorporate black carbon and other short-lived climate forcers into these metrics. Thus, an understanding of the biofuels sector for black carbon and co-pollutant emissions and impacts remains a critical knowledge gap. Here we combine high-resolution agronomic data and regional chemical transport modeling to consider the life-cycle emissions of black carbon from sugarcane ethanol production in Brazil. Furthermore, we explore the potential for significant radiative forcing from the pre-harvest burning of sugarcane fields and the indirect land use emissions associated with deforestation.
Campbell, J.; Spak, S.; Mena-Carrasco, M.; Carmichael, G. R.; Chen, Y.; Tsao, C.
40 CFR 600.114-08 - Vehicle-specific 5-cycle fuel economy and carbon-related exhaust emission calculations.
Code of Federal Regulations, 2013 CFR
...the carbon-related exhaust emissions in grams per mile during the specified bag of the...carbon-related exhaust emissions in grams per mile over Bag Y at temperature X...carbon-related exhaust emissions in grams per mile over the ÔcityÔ portion of...
H. R. 1086: A Bill to amend the Internal Revenue code of 1986 to reduce emissions of carbon dioxide by imposing a tax on certain fuels based on their carbon content, introduced in the House of Representatives, One Hundred Second Congress, First Session, February 21, 1991
A new subchapter would be added to the Internal Revenue Code entitled Carbon Tax on Primary Fossil Fuels. The tax is imposed on coal, petroleum, and natural gas, and is phased in over five years beginning in 1992. The tax on coal is $3.60 per ton in 1992 and climbs to $18.00 per ton in 1996. The tax on petroleum begins at $0.78 per barrel and climbs to $3.90 per barrel in 1996. Natural gas is taxed at $0.096 per MCF in 1992 and $0.48 per MCF in 1996. The bill also describes inflation adjustments.
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A pilot study of A+C method for reducing GHG emissions in construction industry
Carbon dioxide emissions (CO2e) and other greenhouse gases (GHG) have been blamed for global warming, and more and more unforeseeable natural disasters that have put human beings in great danger. Reduction of CO2e is considered one of the most important issues of global politics in the next decade. The construction industry has long been the major contributor of CO2e and
Tsung-Hao Fu; Wen-der Yu
Electron field emission from diamond-like carbon nanodot arrays
NASA Astrophysics Data System (ADS)
Diamond-like carbon (DLC) nanodot arrays were prepared by filtered cathodic arc plasma (FCAP) technique at room temperature with the aid of anodic aluminum oxide (AAO) template at a bias of -50 V. The average diameter of highly ordered and vertical DLC nanodots was ?90 nm, and the nanodot density was estimated to be ?10 10 cm -2. A broad asymmetric band attributed to characteristic band of DLC ranging from 1000 to 2000 cm -1 was detected by Raman spectrum. A sp 3/(sp 3+sp 2) ratio of 68.2% was measured by X-ray photoelectron spectrum (XPS). A low threshold field of 4 V/?m at 10 mA/cm 2 and a high current density of 43.2 mA/cm 2 at 5 V/?m were achieved. And based on Fowler-Nordheim plot, the value of work function for the DLC nanodot arrays was estimated in the range 0.4-1.84 from a linear plot. The results show that the DLC nanodot arrays can be a promising candidate as a field emission emitter.
Li, C.; Yan, P. X.; Li, X. C.; Chong, E. M.
Numerical and experimental studies of enhanced electron emission from functionalized carbon nanotube emitters
NASA Astrophysics Data System (ADS)
Vertically aligned carbon nanotubes (CNTs) were grown using plasma enhanced chemical vapor deposition (PECVD) method. The CNTs were further functionalized by coating their surface with a thin layer of low work function oxide emissive materials. The electron emission capability of the coated CNT emitters was greatly improved with the low work function emissive layer, particularly at high temperature. Thermionic emission current three orders magnitude higher was observed. The emission properties of the oxide coated CNTs were measured and characterized over a wide temperature and field ranges. It was found that neither the Fowler-Nordheim theory for field emission nor the Richardson theory for thermionic emission were adequate to describe the electron emission characteristics of these emitters in certain range of temperature and field. However, by adopting a general electron emission formulism developed by Murphy and Good, we were able to simulate the electron emission from the coated CNTs over the whole temperature and field range and fit the experimental data.
Jin, Feng; Little, Scott; Alzubi, Feras
Trace gas and particle emissions from open burning of three cereal crop residues: Increase in residue moistness enhances emissions of carbon monoxide, methane, and particulate organic carbon
NASA Astrophysics Data System (ADS)
We determined emission factors for open burning of straw of rice, wheat, and barley, as well as rice husks, and we incorporated the effects of moisture content on the emission factors for the straw. A closed system that simulated on-site backfiring of residues on the soil surface under moderate wind conditions was used to measure the gas and particle emissions from open burning of the residues on an upland field. Two moisture content conditions were evaluated: a dry condition (air-dried residues, 11-13% by weight) and a moist condition (20%). When a linear regression model with the initial moisture content of the residue as the explanatory variable showed good correlation between the primary emission data of a substance and the moisture content, the regression model was adopted as a function to give the emission factors. Otherwise, the unmodified primary data were used as the emission factors. The magnitudes of the gas and particle emissions differed among the residue types. For example, carbon monoxide (CO) emissions from straw of rice, wheat, and barley and rice husks burned under the dry condition were 27.2á▒á1.7, 41.8á▒á24.2, 46.9á▒á2.1, and 66.1ágákg-1 dry matter, and emissions of methane (CH4) were 0.75á▒á0.01, 2.01á▒á0.93, 1.47á▒á0.06, and 5.81ágákg-1 dry matter, respectively (ná=á2 for straw with the standard deviation; ná=á1 for husks). Emissions of carbon-containing gases and particles (e.g., CO, CH4, and particulate organic carbon) were higher under the moist condition than under the dry condition, which suggests that emission factors for open burning should incorporate the effects of moisture content except open burning performed in the dry season or arid zones.
Hayashi, Kentaro; Ono, Keisuke; Kajiura, Masako; Sudo, Shigeto; Yonemura, Seiichiro; Fushimi, Akihiro; Saitoh, Katsumi; Fujitani, Yuji; Tanabe, Kiyoshi
Carbon emissions from U.S. ethylene production under climate change policies.
This paper presents the results from a dynamic computer model of U.S. ethylene production, designed to explore implications of alternative climate change policies for the industry's energy use and carbon emissions profiles. The model applies to the aggregate ethylene industry but distinguishes its main cracker types, fuels used as feedstocks and for process energy, as well as the industry's capital vintage structure and vintage-specific efficiencies. Results indicate that policies which increase the cost of carbon of process energy-such as carbon taxes or carbon permit systems-are relatively blunt instruments for cutting carbon emissions from ethylene production. In contrast, policies directly affecting the relative efficiencies of new to old capital-such as R&D stimuli or accelerated depreciation schedules-may be more effective in leveraging the industry's potential for carbon emissions reductions. PMID:11827044
Ruth, Matthias; Amato, Anthony D; Davidsdottir, Brynhildur
Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions
A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.
Biruduganti, Munidhar S. (Naperville, IL); Gupta, Sreenath Borra (Naperville, IL); Sekar, R. Raj (Naperville, IL); McConnell, Steven S. (Shorewood, IL)
Microbial mechanisms to reduce the uncertainties in the CH4 emissions from global rice fields
NASA Astrophysics Data System (ADS)
In terrestrial ecosystems, methane (CH4) uptake or emission represents the net balance between activities of different microbial organisms including anaerobic Methanogens that produce CH4 and Methanotrophs which oxidize CH4 in the aerobic environments. In this way, anaerobic soil environments such as rice fields are major source of terrestrial CH4 emissions. However, large uncertainties in the CH4 emission estimates have been reported from rice fields. The bottom-up and top-down methods showed a wide range of CH4 emissions estimations ranging from 25 to 300 Tg yr-1 from rice fields. The major reason for uncertainties in the CH4 emissions includes the water management that alters the balance of Methanogens and Methanotrophs in the rice fields. Two kinds of water management p