query: Goklany has argued that the rising level of carbon dioxide in the earth’s atmosphere ‘is currently net beneficial for both humanity and the biosphere generally.”

positive: Carbon dioxide Carbon dioxide ( chemical formula ) is a colorless gas with a density about 60 % higher than that of air ( 1.225 g/L ) that is odorless at normally encountered concentrations . Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms . It occurs naturally in Earth 's atmosphere as a trace gas at a concentration of about 0.04 percent ( 400 ppm ) by volume . Natural sources include volcanoes , hot springs and geysers , and it is freed from carbonate rocks by dissolution in water and acids . Because carbon dioxide is soluble in water , it occurs naturally in groundwater , rivers and lakes , ice caps , glaciers and seawater . It is present in deposits of petroleum and natural gas .   As the source of available carbon in the carbon cycle , atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth 's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena . Plants , algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water , with oxygen produced as a waste product .   Carbon dioxide is produced by all aerobic organisms when they metabolize carbohydrates and lipids to produce energy by respiration . It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals , including humans . Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread , beer and winemaking . It is produced by combustion of wood and other organic materials and fossil fuels such as coal , peat , petroleum and natural gas .   It is a versatile industrial material , used , for example , as an inert gas in welding and fire extinguishers , as a pressurizing gas in air guns and oil recovery , as a chemical feedstock and in liquid form as a solvent in decaffeination of coffee and supercritical drying . It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence . The frozen solid form of , known as `` dry ice '' is used as a refrigerant and as an abrasive in dry-ice blasting .   Carbon dioxide is the most significant long-lived greenhouse gas in Earth 's atmosphere . Since the Industrial Revolution anthropogenic emissions - primarily from use of fossil fuels and deforestation - have rapidly increased its concentration in the atmosphere , leading to global warming . Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid .

positive: Carbon dioxide in Earth's atmosphere Carbon dioxide is an important trace gas in Earth 's atmosphere . Currently it constitutes about 0.041 % ( equal to 410 parts per million ; ppm ) by volume of the atmosphere . Despite its relatively small concentration is a potent greenhouse gas and plays a vital role in regulating Earth 's surface temperature through radiative forcing and the greenhouse effect . Reconstructions show that concentrations of in the atmosphere have varied , ranging from as high as 7,000 ppm during the Cambrian period about 500 million years ago to as low as 180 ppm during the Quaternary glaciation of the last two million years .   Carbon dioxide is an integral part of the carbon cycle , a biogeochemical cycle in which carbon is exchanged between the Earth 's oceans , soil , rocks and the biosphere . Plants and other photoautotrophs use solar energy to produce carbohydrate from atmospheric carbon dioxide and water by photosynthesis . Almost all other organisms depend on carbohydrate derived from photosynthesis as their primary source of energy and carbon compounds .   The current episode of global warming is attributed to increasing emissions of and other greenhouse gases into Earth 's atmosphere . The global annual mean concentration of in the atmosphere has increased by more than 40 % since the start of the Industrial Revolution , from 280 ppm , the level it had for the last 10,000 years leading up to the mid-18th century , to 399 ppm as of 2015 . The present concentration is the highest in at least the past 800,000 years and likely the highest in the past 20 million years . The increase has been caused by anthropogenic sources , particularly the burning of fossil fuels and deforestation . The daily average concentration of atmospheric CO2 at Mauna Loa Observatory first exceeded 400 ppm on 10 May 2013 . It is currently rising at a rate of approximately 2 ppm/year and accelerating . An estimated 30 -- 40 % of the released by humans into the atmosphere dissolves into oceans , rivers and lakes , which contributes to ocean acidification .

positive: Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years .   In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing .   Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years .   Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) ,  whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change .   Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned .

positive: Snowball Earth The Snowball Earth hypothesis proposes that Earth 's surface became entirely or nearly entirely frozen at least once , sometime earlier than 650 Mya ( million years ago ) . Proponents of the hypothesis argue that it best explains sedimentary deposits generally regarded as of glacial origin at tropical palaeolatitudes , and other enigmatic features in the geological record . Opponents of the hypothesis contest the implications of the geological evidence for global glaciation and the geophysical feasibility of an ice - or slush-covered ocean , and emphasize the difficulty of escaping an all-frozen condition . A number of unanswered questions remain , including whether the Earth was a full snowball , or a `` slushball '' with a thin equatorial band of open ( or seasonally open ) water .   The snowball Earth episodes occurred before the sudden radiation of multicellular bioforms , known as the Cambrian explosion . The most recent snowball episode may have triggered the evolution of multicellularity . Another , much earlier and longer snowball episode , the Huronian glaciation , which occurred 2400 to 2100 Mya , may have been triggered by the first appearance of oxygen in the atmosphere , the `` Great Oxygenation Event . ''

positive: Carbon dioxide removal Carbon dioxide removal ( CDR ) methods refers to a number of technologies which reduce the levels of carbon dioxide in the atmosphere . Among such technologies are bio-energy with carbon capture and storage , biochar , direct air capture , ocean fertilization and enhanced weathering . CDR is a different approach than removing CO2 from the stack emissions of large fossil fuel point sources , such as power stations . The latter reduces emission to the atmosphere but can not reduce the amount of carbon dioxide already in the atmosphere . As CDR removes carbon dioxide from the atmosphere , it creates negative emissions , offsetting emissions from small and dispersed point sources such as domestic heating systems , airplanes and vehicle exhausts . It is regarded by some as a form of climate engineering , while other commentators describe it as a form of carbon capture and storage or extreme mitigation . Whether CDR would satisfy common definitions of `` climate engineering '' or `` geoengineering '' usually depends upon the scale on which it would be undertaken .   The likely need for CDR has been publicly expressed by a range of individuals and organizations involved with climate change issues , including IPCC chief Rajendra Pachauri , the UNFCCC executive secretary Christiana Figueres , and the World Watch Institute . Institutions with major programs focusing on CDR include the Lenfest Center for Sustainable Energy at the Earth Institute , Columbia University , and the Climate Decision Making Center , an international collaboration operated out of Carnegie-Mellon University 's Department of Engineering and Public Policy .   The mitigation effectiveness of air capture is limited by societal investment , land use , availability of geologic reservoirs , and leakage . The reservoirs are estimated to be sufficient to for storing at least 545 GtC . Storing 771 GtC would cause an 186 ppm atmospheric reduction . In order to return the atmospheric CO2 content to 350 ppm we need atmospheric reduction of 50 ppm plus an additional 2 ppm per year of current emissions .

negative: Atmospheric methane Atmospheric methane is the methane present in Earth 's atmosphere . Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth 's atmosphere . The 100-year global warming potential of methane is 28 . That is , over a 100-year period , it traps 28 times more heat per mass unit than carbon dioxide and 32 times the effect when accounted for aerosol interactions . Global methane levels , had risen to 1800 parts per billion ( ppb ) by 2011 , an increase by a factor of 2.5 since pre-industrial times , from 722 ppb , the highest value in at least 800,000 years . Its concentration is higher in the Northern Hemisphere since most sources ( both natural and human ) are located on land and the Northern Hemisphere has more land mass . The concentrations vary seasonally , with , for example , a minimum in the northern tropics during April − May mainly due to removal by the hydroxyl radical .   Early in the Earth 's history carbon dioxide and methane likely produced a greenhouse effect . The carbon dioxide would have been produced by volcanoes and the methane by early microbes . During this time , Earth 's earliest life appeared . These first , ancient bacteria added to the methane concentration by converting hydrogen and carbon dioxide into methane and water . Oxygen did not become a major part of the atmosphere until photosynthetic organisms evolved later in Earth 's history . With no oxygen , methane stayed in the atmosphere longer and at higher concentrations than it does today .   Methane is created near the surface , and it is carried into the stratosphere by rising air in the tropics . Uncontrolled build-up of methane in Earth 's atmosphere is naturally checked -- although human influence can upset this natural regulation -- by methane 's reaction with hydroxyl radicals formed from singlet oxygen atoms and with water vapor .

negative: Scott Denning A. Scott Denning is a climate scientist and professor of atmospheric science at Colorado State University , whose faculty he joined in 1998 . He is known for his research into atmosphere-biosphere interactions and atmospheric carbon dioxide . He firmly supports action to avoid dangerous climate change and has said that the science behind it is `` settled '' . He has also argued that , if no action is taken on the matter , global warming could cause the climate of Colorado to resemble the current climate of its neighbors to the south , such as southern New Mexico , Texas and Mexico .

negative: Black carbon Chemically , black carbon ( BC ) is a component of fine particulate matter ( PM ≤ 2.5 µm in aerodynamic diameter ) . Black carbon consists of pure carbon in several linked forms . It is formed through the incomplete combustion of fossil fuels , biofuel , and biomass , and is emitted in both anthropogenic and naturally occurring soot .   Black carbon causes human morbidity and premature mortality .   In climatology , black carbon is a climate forcing agent . Black carbon warms the Earth by absorbing sunlight and heating the atmosphere and by reducing albedo when deposited on snow and ice ( direct effects ) and indirectly by interaction with clouds , with the total forcing of 1.1 W/m2 . Black carbon stays in the atmosphere for only several days to weeks , whereas carbon dioxide has an atmospheric lifetime of more than 100 years .   The term black carbon is also used in soil sciences and geology , referring either to deposited atmospheric black carbon or to directly incorporated black carbon from vegetation fires . Especially in the tropics , black carbon in soils significantly contributes to fertility as it is able to absorb important plant nutrients .

negative: Capnophile Capnophiles are microorganisms that thrive in the presence of high concentrations of carbon dioxide .   Some capnophiles may have a metabolic requirement for carbon dioxide , while others merely compete more successfully for resources under these conditions . The term is a generally descriptive one and has less relevance as a means of establishing a taxonomic or evolutionary relationship among organisms with this characteristic .   For example , the ability of capnophiles to tolerate ( or utilize ) the amount of oxygen that is also in their environment may vary widely and may be far more critical to their survival . Species of Campylobacter are bacterial capnophiles that are more easily identified because they are also microaerophiles , organisms that can grow in high carbon dioxide as long as a small amount of free oxygen is present , but at a dramatically reduced concentration . ( In the earth 's atmosphere carbon dioxide levels are approximately five hundred times lower than that of oxygen , 0.04 % and 21 % of the total , respectively . ) Obligate anaerobes are microbes that will die in the presence of oxygen without respect to the concentration of carbon dioxide in their environment , and typically acquire energy through anaerobic respiration , or fermentation ( biochemistry ) .   In 2004 , a capnophilic bacterium was characterized that appears to require carbon dioxide . This organism , Mannheimia succiniciproducens , has a unique metabolism involving carbon fixation . While carbon fixation is common to most plant life on earth since it is the key initial step in the biosynthesis of complex carbon compounds during photosynthesis ( the Calvin cycle ) , it is found in relatively few microorganisms and not found in animals . Mannheimia succiniciproducens can attach carbon dioxide to the three-carbon backbone of phosphoenolpyruvate , an endproduct in glycolysis , to generate the four-carbon compound , oxaloacetic acid , an intermediate in the Krebs cycle . Although Mannheimia succiniciproducens has most of the intermediates in the Krebs cycle , it is not capable of oxidative phosphorylation , the final step in the electron transport chain that would allow it to carry out the highly efficient process of harvesting energy by aerobic respiration .

negative: Global Carbon Project The Global Carbon Project ( GCP ) was established in 2001 . The organisation seeks to quantify global carbon emissions and their causes .   The main object of the group has been to fully understand the carbon cycle . The project has brought together emissions experts and economists to tackle the problem of rising concentrations of greenhouse gases .   The Global Carbon Project works collaboratively with the International Geosphere-Biosphere Programme , the World Climate Programme , the International Human Dimensions Programme on Global Environmental Change and Diversitas , under the Earth System Science Partnership .   In late 2006 researchers from the project claimed that carbon dioxide emissions had dramatically increased to a rate of 3.2 % annually from 2000 . At the time , the chair of the group Dr Mike Raupach stated that `` This is a very worrying sign . It indicates that recent efforts to reduce emissions have had virtually no impact on emissions growth and that effective caps are urgently needed , '' .   A 2010 study conducted by the Project and Nature Geoscience revealed that the world 's oceans absorb 2.3 billion metric tonnes of carbon dioxide .   On December 5 , 2011 analysis released from the project claimed carbon dioxide from fossil-fuel burning jumped by the largest amount on record in 2010 to 5.9 percent from a growth rate in the 1990s closer to 1 percent annually . The combustion of coal represented more than half of the growth in emissions , the report found .   They predict greenhouse gas emissions to occur according to the IPCC 's worst-case scenario , as CO2 concentration in the atmosphere reaches 500ppm in the 21st century .

negative: Guy Stewart Callendar Guy Stewart Callendar ( February 1897 - October 1964 ) was an English steam engineer and inventor . His main contribution to knowledge was developing the theory that linked rising carbon dioxide concentrations in the atmosphere to global temperature . This theory , earlier proposed by Svante Arrhenius , has been called the Callendar effect . Callendar thought this warming would be beneficial , delaying a `` return of the deadly glaciers . ''

negative: Kaya identity The Kaya identity is an identity stating that the total emission level of the greenhouse gas carbon dioxide can be expressed as the product of four factors : human population , GDP per capita , energy intensity ( per unit of GDP ) , and carbon intensity ( emissions per unit of energy consumed ) . It is a concrete form of the more general I = PAT equation relating factors that determine the level of human impact on climate . The Kaya identity is both simple and tricky , as it can be reduced to only two terms , but it is developed so that the carbon emission calculation becomes easy , as per the available data , or generally in which format the data is available .

negative: Cap carbonate Cap carbonates are layers of distinctively textured carbonate rocks which typically form the uppermost layer of sedimentary sequences reflecting major glaciations in the geological record .   The rising temperatures , and increased oceanic surface area - due to reduced ice cover and rising sea levels - at the end of a glaciation increase the rate of precipitation .   High concentrations of greenhouse gases such as carbon dioxide ( CO2 ) must build up in the atmosphere to overcome the effect of the high reflectivity ( albedo ) of ice and allow temperatures to rise sufficiently to begin melting .   Increased precipitation dissolves carbon dioxide from the atmosphere , falling as a weak carbonic acid - acid rain .   This would weather exposed silicate and carbonate rock , including readily-attacked glacial debris , which would release large amounts of calcium . When washed into the ocean , these precipitate to form distinctively textured layers of carbonate sedimentary rock .   A heavily debated cap carbonate appears at the top of the Gaskiers glaciation , believed by many to be global in extent .

negative: Carbonate–silicate cycle The carbonate -- silicate geochemical cycle describes the transformation of silicate rocks to carbonate rocks by weathering and sedimentation at Earth 's surface and the transformation of carbonate rocks back into silicates by metamorphism and magmatism . It plays a large part in the carbon cycle , since the equilibrium point of the carbonate-silicate cycle dictates the pace of carbon release from the lithosphere .   The carbonate-silicate cycle involves several chemical reactions that occur in different environments . In the atmosphere , gaseous carbon dioxide ( CO2 ) dissolves in rainwater , forming natural carbonic acid ( H2CO3 ) . This weak acid weathers silicate rocks on continents , slowly dissolving the rock and releasing aqueous minerals through the chemical reaction CaSiO3 ( s ) ( wollastonite ) + 2CO2 ( g ) + H2O ( l ) → Ca + 2HCO ( aq ) ( bicarbonate ) + SiO2 ( aq ) ( dissolved silica ) . These dissolved minerals are eventually carried by water to the ocean , where they are used by living organisms such as foraminifera , radiolarians , coccolithopores , and diatoms to create shells of CaCO3 ( calcite ) or SiO2 ( opal ) through the reactions Ca2 + ( aq ) + 2HCO3 → CaCO3 ( s ) + CO2 ( g ) + H2O ( l ) ( for calcite precipitation ) and SiO2 ( aq ) → SiO2 ( s ) ( for opal precipitation ) . When these organisms die , many shells are remineralized but some shells fall all the way to the sea floor and are buried . The cycle is completed when the sea floor is subducted and carbonate minerals recombine with silicate minerals under temperatures above 300 ° C to reform calcium silicates and release gaseous CO2 through volcanism ( CaCO3 ( s ) + SiO2 ( s ) → CaSiO3 ( s ) + CO2 ( g ) ) .   The carbonate-silicate cycle impacts the global carbon cycle , as carbon dioxide is removed from the Earth 's surface through the burial of weathered minerals in deep ocean sediments and returned to the atmosphere through metamorphism and volcanism . However , this process is far from being a closed loop . In Earth history generally the formation of carbonates significantly outpaces the formation of silicates , effectively removing carbon dioxide from the atmosphere . Because carbon dioxide is a potent greenhouse gas , the carbonate-silicate cycle is suspected to initiate ice ages by creating a negative feedback on the global temperature with a typical time scale of a few million years that is capable of countering water vapor and carbon dioxide short-term positive feedback on global temperature .   The carbonate-silicate cycle equilibrium point is shifted on Venus due to surface temperatures above 300 ° C , which favor the formation of calcium silicates over weathering . Thus , Venus has a high-density carbon-dioxide atmosphere .

negative: Keeling Curve The Keeling Curve is a graph that plots the ongoing change in concentration of carbon dioxide in Earth 's atmosphere since the 1950s . It is based on continuous measurements taken at the Mauna Loa Observatory in Hawaii that began under the supervision of Charles David Keeling . Keeling 's measurements showed the first significant evidence of rapidly increasing carbon dioxide levels in the atmosphere . Many scientists credit Keeling 's graph with first bringing the world 's attention to the current increase of carbon dioxide in the atmosphere .   Charles David Keeling , of Scripps Institution of Oceanography at UC San Diego , was the first person to make frequent regular measurements of the atmospheric carbon dioxide ( CO2 ) concentration , taking readings at the South Pole and in Hawaii from 1958 onwards .   Measurements of carbon dioxide concentrations in the atmosphere had been taken prior to the Mauna Loa measurements , but on an ad-hoc basis across a variety of locations . Guy Stewart Callendar had shown a steady increase in concentrations since the 19th century . Keeling had perfected the measurement techniques and observed `` strong diurnal behavior with steady values of about 310 ppm in the afternoon '' at three locations : Big Sur near Monterey , the rain forests of Olympic Peninsula , and high mountain forests in Arizona . By measuring the ratio of two isotopes of carbon , Keeling attributed the diurnal change to respiration from local plants and soils , with afternoon values representative of the `` free atmosphere '' . By 1960 , Keeling and his group had determined that the measurement records from California , Antarctica , and Hawaii were long enough to see not just the diurnal and seasonal variations , but also a year-on-year increase that roughly matched the amount of fossil fuels burned per year . In the article that made him famous , Keeling observed : `` at the South Pole the observed rate of increase is nearly that to be expected from the combustion of fossil fuel '' .

negative: Carbon sequestration Carbon sequestration is the process involved in carbon capture and the long-term storage of atmospheric carbon dioxide . Carbon sequestration involves long-term storage of carbon dioxide or other forms of carbon to mitigate or defer global warming . It has been proposed as a way to slow the atmospheric and marine accumulation of greenhouse gases , which are released by burning fossil fuels .   Carbon dioxide is naturally captured from the atmosphere through biological , chemical , and physical processes . Artificial processes have been devised to produce similar effects , including large-scale , artificial capture and sequestration of industrially produced using subsurface saline aquifers , reservoirs , ocean water , aging oil fields , or other carbon sinks .

negative: International Geosphere-Biosphere Programme The International Geosphere-Biosphere Programme ( IGBP ) was a research programme that studies the phenomenon of global change . It closed in 2015   The International Council of Scientific Unions , a coordinating body of national science organizations , launched IGBP in 1987 . It looked at the total Earth system , the changes that are occurring , and the manner in which changes are influenced by human actions .   IGBP aimed to describe and understand how the physical , chemical and biological processes regulate the Earth system . It also seeks to increase knowledge of how humans are influencing the global processes , such as the carbon cycle , nitrogen cycle , sulfur cycle , water cycle and phosphorus cycle . `` It delivers scientific knowledge to help human societies develop in harmony with Earth 's environment . ''   IGBP research is organised around six projects representing the Earth system - land , atmosphere , ocean and where they meet ( land-atmosphere , land-ocean . atmosphere-ocean ) and two further projects looking at the Earth system as a whole : Past Global Changes ( PAGES ) which looks at palaeoclimate , and the Analysis , Integration and Modelling of the Earth System ( AIMES ) , which helps set the agenda for Earth system models . Plus four joint projects - carbon , water , human health and food security - with the other three international global-change programmes .   In 2004 , IGBP published a landmark synthesis , Global Change and the Earth System ( Steffen et al ) . The synthesis stated that humanity was now the main driver of change at the planetary scale and that Earth is now operating in a `` no analogue '' state . Measurements of Earth system processes , past and present , have led to the conclusion that the planet has moved well outside the range of natural variability in the last half million years at least .   Sybil Seitzinger is the Executive Director .

negative: Polar forests of the Cretaceous Cretaceous polar forests were temperate forests that grew at polar latitudes during the final period of the Mesozoic Era , known as the Cretaceous Period 145 -- 66 Ma . During this period , global average temperature was about 10 C-change higher and carbon dioxide ( CO2 ) levels were approximately 1000 parts per million ( ppm ) , 2.5 times the current concentration in Earth 's atmosphere . The abundance of atmospheric carbon dioxide had a very significant impact on global climate and Earth 's natural systems as its concentration is considered one of the main factors in the development of a pronounced greenhouse Earth during the Cretaceous with a very low average global temperature gradient . As a consequence , high paleolatitudes in both hemispheres were much warmer than at present . This temperature gradient was partly responsible for the lack of continental ice sheets in polar regions .   As a response to elevated global temperatures , the Earth 's hydrologic cycle was significantly enhanced due to greater volume of moisture evaporation from the surface of the ocean . In turn , the absolute sea level during this time period stood at elevations much higher than the present level . Continental encroachment of seawater formed widespread shallow seas , including expanses of epeiric seas .   An increase in surface area between shallow , warm epeiric seawater and the atmosphere permits higher evaporation rates and more precipitation at various latitudes , producing a more temperate global climate . A widespread temperate climate also had significant effects on high latitude ecosystems .

negative: Carbon dioxide generator A Carbon dioxide generator or CO2 generator is a machine used to enhance carbon dioxide levels in order to promote plant growth in greenhouses or other enclosed areas . Carbon dioxide generators have been used to help grow marijuana . They can be fueled with propane or natural gas . CO2 generators were used mostly by commercial growers until smaller and less expansive systems made the technology more widely available to hobbyists . The generators also give off heat . Using compressed CO2 is an alternative to generators .

negative: Respiratory failure Respiratory failure results from inadequate gas exchange by the respiratory system , meaning that the arterial oxygen , carbon dioxide or both can not be kept at normal levels . A drop in the oxygen carried in blood is known as hypoxemia ; a rise in arterial carbon dioxide levels is called hypercapnia . Respiratory failure is classified as either Type I or Type II , based on whether there is a high carbon dioxide level . The definition of respiratory failure in clinical trials usually includes increased respiratory rate , abnormal blood gases ( hypoxemia , hypercapnia , or both ) , and evidence of increased work of breathing .   The normal partial pressure reference values are : oxygen PaO2 more than 80 mmHg , and carbon dioxide PaCO2 lesser than 45 mmHg .

negative: Biosphere model In climate science , a biosphere model , is used to model the biosphere of Earth , and can be coupled with atmospheric general circulation models ( GCMs ) for modelling the entire climate system .

negative: The Nitrogen Fix The Nitrogen Fix is a 1980 science fiction novel by Hal Clement . The plot revolves around a nomadic family in a future where all oxygen in the Earth 's atmosphere has combined with nitrogen , so the atmosphere is mostly nitrogen with traces of water , nitrogen oxides and carbon dioxide , and the seas are very dilute nitric acid .

negative: Estuarine acidification Estuarine acidification is a decrease in the pH of coastal marine ecosystems , specifically those of estuaries . pH change in estuaries is more complicated than in the open ocean due to direct impacts from land run-off and coastal current dynamics . Ocean acidification is the ongoing decrease in the pH of the Earth 's oceans , caused by the absorption of carbon dioxide ( CO2 ) from the atmosphere ( 0.1 units over the last century ) . The ocean absorbs 30-40 % of all CO2 emitted to the atmosphere ; this increase in aqueous carbon dioxide causes a decline in the pH of the ocean surface . As carbon dioxide combines with water , it releases protons ( hydrogen ions ) , based on the following equation :   CO2 + H2O ↔ H2CO3 ↔ HCO3 + H + ↔ CO3 + 2 H +

negative: Dry ice Dry ice , sometimes referred to as `` cardice '' ( chiefly by British chemists ) , is the solid form of carbon dioxide . It is used primarily as a cooling agent . Its advantages include lower temperature than that of water ice and not leaving any residue ( other than incidental frost from moisture in the atmosphere ) . It is useful for preserving frozen foods where mechanical cooling is unavailable .   Dry ice sublimates at − 78.5 ° C ( − 109.3 ° F ) at Earth atmospheric pressures . This extreme cold makes the solid dangerous to handle without protection due to burns caused by freezing ( frostbite ) . While generally not very toxic , the outgassing from it can cause hypercapnia ( abnormally elevated carbon dioxide levels in the blood ) due to buildup in confined locations .

negative: Total Carbon Column Observing Network The Total Carbon Column Observing Network ( TCCON ) is a global network of instruments that measure the amount of carbon dioxide , methane , carbon monoxide , nitrous oxide and other trace gases in the Earth 's atmosphere . The TCCON ( -LSB- ˈtiːkɒn -RSB- ) began in 2004 with the installation of the first instrument in Park Falls , Wisconsin , USA , and has since grown to 23 operational instruments worldwide , with 7 former sites . The TCCON is designed to investigate several things , including the flow ( or flux ) of carbon between the atmosphere , land , and ocean ( the so-called carbon budget or carbon cycle ) . This is achieved by measuring the atmospheric mass of carbon ( the airborne fraction ) . The TCCON measurements have improved the scientific community 's understanding of the carbon cycle , and urban greenhouse gas emissions . The TCCON supports several satellite instruments by providing an independent measurement to compare ( or validate ) the satellite measurements of the atmosphere over the TCCON site locations . The TCCON provides the primary measurement validation dataset for the Orbiting Carbon Observatory ( OCO-2 ) mission , and has been used to validate other space-based measurements of carbon dioxide .

negative: Asphyxiant gas An asphyxiant gas is a nontoxic or minimally toxic gas which reduces or displaces the normal oxygen concentration in breathing air . Breathing of oxygen-depleted air can lead to death by asphyxiation ( suffocation ) . Because asphyxiant gases are relatively inert and odorless , their presence in high concentration may not be noticed , except in the case of carbon dioxide ( hypercapnia ) .   Toxic gases , by contrast , cause death by other mechanisms , such as competing with oxygen on the cellular level ( e.g. carbon monoxide ) or directly damaging the respiratory system ( e.g. phosgene ) . Far smaller quantities of these are deadly .   Notable examples of asphyxiant gases are nitrogen , argon , helium , butane and propane . Along with trace gases such as carbon dioxide and ozone , these compose 79 % of Earth 's atmosphere . The atmosphere is mostly harmless because the remaining 21 % is O2 .

negative: Environmental issue Environmental issues are harmful trouble effects of human activity on the biophysical environment . Environmental protection is a practice of protecting the natural environment on individual , organizational or governmental levels , for the benefit of both the environment and humans . Environmentalism , a social and environmental movement , addresses environmental issues through advocacy , education and activism .   The carbon dioxide equivalent of greenhouse gases ( GHG ) in the atmosphere has already exceeded 400 parts per million ( NOAA ) ( with total `` long-term '' GHG exceeding 455 parts per million ) . ( Intergovernmental Panel on Climate Change Report ) This level is considered a tipping point .  `` The amount of greenhouse gas in the atmosphere is already above the threshold that can potentially cause dangerous climate change . We are already at risk of many areas of pollution ... It 's not next year or next decade , it 's now . ''  Report from the UN Office for the Coordination of Humanitarian Affairs ( OCHA ) :   Environment destruction caused by humans is a global problem , and this is a problem that is on going every day . By year 2050 , the global human population is expected to grow by 2 billion people , thereby reaching a level of 9.6 billion people ( Living Blue Planet 24 ) . The human effects on Earth can be seen in many different ways . A main one is the temperature rise , and according to the report '' Our Changing Climate '' , the global warming that has been going on for the past 50 years is primarily due to human activities ( Walsh , et al. 20 ) . Since 1895 , the U.S. average temperature has increased from 1.3 ° F to 1.9 ° F , with most of the increase taken place since around year 1970 ( Walsh , et al. 20 ) .

negative: Deep Earth Carbon Degassing Project Deep Earth Carbon Degassing ( DECADE ) project is an initiative to unite scientists around the world to make tangible advances towards quantifying the amount of carbon outgassed from the Earth 's deep interior ( core , mantle , crust ) into the surface environment ( e.g. biosphere , hydrosphere , cryosphere , atmosphere ) through naturally occurring processes . DECADE is an initiative within the Deep Carbon Observatory ( DCO ) .   Volcanoes are the main pathway in which deeply-sourced volatiles , including carbon , are transferred from the Earth 's interior to the surface environment . An additional , though less well understood pathway includes along faults and fractures within the Earth 's crust , often referred to as tectonic degassing . When the DCO was first formed in 2009 estimates of global carbon flux from volcanic regions ranged from 65 to 540 Mt/yr , and constraints on global tectonic degassing were virtually unknown . The order of magnitude uncertainty in current volcanic/tectonic carbon outgassing makes answering fundamental questions about the global carbon budget virtually impossible . In particular , one fundamental unknown is if carbon transferred to the Earth 's interior via subduction is efficiently recycled back to the Earth 's mantle lithosphere , crust and surface environment through volcanic and tectonic degassing , or if significant quantities of carbon are being subducted into the deep mantle . Because significant quantities of mantle carbon are also released through Mid-Ocean Ridge volcanism , if carbon inputs and outputs at subduction zone settings are in balance , then the net effect will be an imbalance in the global carbon budget , with carbon being preferentially removed from the Earth 's deep interior and redistributed to more shallow reservoirs including the mantle lithosphere , crust , hydrosphere and atmosphere . The implications of this may mean that carbon concentrations in the surface environment are increasing over Earth 's history , which has significant implications for climate change .   Findings from the DECADE project will increase our understanding of the way carbon cycles through deep Earth , and patterns in volcanic emissions data could potentially alert scientists to an impending eruption .

negative: Ocean acidification Ocean acidification is the ongoing decrease in the pH of the Earth 's oceans , caused by the uptake of carbon dioxide from the atmosphere . Seawater is slightly basic ( meaning pH > 7 ) , and the process in question is a shift towards pH-neutral conditions rather than a transition to acidic conditions ( pH < 7 ) . Ocean alkalinity is not changed by the process , or may increase over long time periods due to carbonate dissolution . An estimated 30 -- 40 % of the carbon dioxide from human activity released into the atmosphere dissolves into oceans , rivers and lakes . To achieve chemical equilibrium , some of it reacts with the water to form carbonic acid . Some of these extra carbonic acid molecules react with a water molecule to give a bicarbonate ion and a hydronium ion , thus increasing ocean acidity ( H + ion concentration ) . Between 1751 and 1996 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14 , representing an increase of almost 35 % in H + ion concentration in the world 's oceans . Earth System Models project that within the last decade ocean acidity exceeded historical analogues and in combination with other ocean biogeochemical changes could undermine the functioning of marine ecosystems and disrupt the provision of many goods and services associated with the ocean .   Increasing acidity is thought to have a range of potentially harmful consequences for marine organisms , such as depressing metabolic rates and immune responses in some organisms , and causing coral bleaching . By increasing the presence of free hydrogen ions , each molecule of carbonic acid that forms in the oceans ultimately results in the conversion of two carbonate ions into bicarbonate ions . This net decrease in the amount of carbonate ions available makes it more difficult for marine calcifying organisms , such as coral and some plankton , to form biogenic calcium carbonate , and such structures become vulnerable to dissolution . Ongoing acidification of the oceans threatens food chains connected with the oceans . As members of the InterAcademy Panel , 105 science academies have issued a statement on ocean acidification recommending that by 2050 , global emissions be reduced by at least 50 % compared to the 1990 level .   While ongoing ocean acidification is anthropogenic in origin , it has occurred previously in Earth 's history . The most notable example is the Paleocene-Eocene Thermal Maximum ( PETM ) , which occurred approximately 56 million years ago . For reasons that are currently uncertain , massive amounts of carbon entered the ocean and atmosphere , and led to the dissolution of carbonate sediments in all ocean basins .   Ocean acidification has been called the `` evil twin of global warming '' and `` the other problem '' .

negative: Carbonated drink Carbonated drinks are beverages that contain dissolved carbon dioxide . The dissolution of CO2 in a liquid , gives rise to fizz or effervescence . The process usually involves carbon dioxide under high pressure . When the pressure is removed , the carbon dioxide is released from the solution as small bubbles , which causes the solution to become effervescent , or fizzy . A common example is the dissolving of carbon dioxide in water , resulting in carbonated water . Carbon dioxide is only weakly soluble in water , therefore it separates into a gas when the pressure is released .   Carbonated beverages are prepared by mixing flavored syrup with carbonated water , both chilled . Carbonation levels range up to 5 volumes of CO2 per liquid volume . Ginger ale , colas , and related drinks are carbonated with 3.5 volumes . Other drinks , often fruity ones , are carbonated less .

negative: Space-based measurements of carbon dioxide Space-based measurements of carbon dioxide are used to help answer questions about Earth 's carbon cycle . There are a variety of active and planned instruments for measuring carbon dioxide in Earth 's atmosphere from space . The first satellite mission designed to measure was the Interferometric Monitor for Greenhouse Gases ( IMG ) on board the ADEOS I satellite in 1996 . This mission lasted less than a year . Since then , additional space-based measurements have begun , including those from two high-precision ( better than 0.3 % or 1 ppm ) satellites ( GOSAT and OCO-2 ) . Different instrument designs may reflect different primary missions .

negative: Vladimir Paar Vladimir Paar ( born 1942 ) is a Croatian physicist and university professor .   Paar was born in Zagreb . He graduated from the Faculty of Science , University of Zagreb , where he is currently a professor . He is a full member of the Croatian Academy of Sciences and Arts since 1992 .   His scientific interests include theoretical nuclear physics , chaos theory in physics and technology , computer modeling in clinical medicine , energetics , and history of physics . To the general public he is known as a popularizer of science , being the author of two books , hundreds of newspaper articles and several television series in the field of popular science .   Paar is a global warming skeptic and is an advocate of a new ice age hypothesis . He argues that the rise of carbon dioxide level in the atmosphere is the effect - rather than the cause - of global climate change , and that the true cause lies in the change of Earth 's orbit due to gravitational pull of Jupiter and other planets of the Solar System . Paar believes that the evidence against anthropogenic global warming is being deliberately suppressed .

negative: Terraforming of Venus The terraforming of Venus is the hypothetical process of engineering the global environment of the planet Venus in such a way as to make it suitable for human habitation . Terraforming Venus was first seriously proposed by the astronomer Carl Sagan in 1961 , although fictional treatments , such as The Big Rain by Poul Anderson , preceded it . Adjustments to the existing environment of Venus to support human life would require at least three major changes to the planet . These three changes are closely interrelated , because Venus 's extreme temperature is due to the greenhouse effect caused by its dense carbon-dioxide atmosphere :  Reducing Venus 's surface temperature of 462 C.  Eliminating most of the planet 's dense 9.2 MPa carbon dioxide and sulfur dioxide atmosphere , via removal or conversion to some other form .  Addition of breathable oxygen to the atmosphere .

negative: Bomb pulse The bomb pulse is the sudden increase of carbon-14 ( 14C ) in the Earth 's atmosphere due to the hundreds of aboveground nuclear bombs tests started in 1945 and intensified between 1950 until 1963 when the Limited Test Ban Treaty was signed by the United States , the Soviet Union and Great Britain . These hundreds of blasts were followed by a doubling of the concentration of 14C in the atmosphere . Since then , the concentration of 14C has decreased towards the previous level . Carbon-14 , the radioisotope of carbon-12 , is naturally developed in trace amounts in the atmosphere and it can be detected in all living organisms . Carbon of all types is continually used to form the molecules of the cells of organisms . Doubling of the concentration of 14C in the atmosphere is reflected in the tissues and cells of all organisms that lived around the period of nuclear testing . This property has many applications in the fields of biology and forensics .

negative: 350.org 350 . org is an international environmental organization encouraging citizens to action with the belief that publicizing the increasing levels of carbon dioxide will pressure world leaders to address climate change and to reduce levels from 400 parts per million to 350 parts per million . It was founded by author Bill McKibben with the goal of building a global grassroots movement to raise awareness about human-driven climate change , to confront climate change denial , and to cut emissions of carbon dioxide in order to slow the rate of global warming . 350 . org takes its name from the research of Goddard Institute for Space Studies scientist James E. Hansen , who posited in a 2007 paper that 350 parts-per-million ( ppm ) of CO2 in the atmosphere is a safe upper limit to avoid a climate tipping point .

negative: Extracorporeal carbon dioxide removal Extracorporeal carbon dioxide removal ( ECCO2R ) is the removal of carbon dioxide ( CO2 ) from the bloodstream in people who have elevated levels of carbon dioxide as a result of respiratory failure .   The use of extracorporeal carbon dioxide removal is currently considered experimental , but it has been studied in a number of situations , specifically severe exacerbations of chronic obstructive pulmonary disease and in adult respiratory distress syndrome where conventional mechanical ventilation would cause excessive lung damage .   It requires the insertion of a tube similar to a dialysis catheter into a large vein . Blood is pumped through a machine where the carbon dioxide is filtered out .

negative: Eyes on the Earth Eyes on the Earth ( EoE ) is computer visualization software created by the Jet Propulsion Laboratory ( JPL ) to visualize a number of NASA 's Earth orbiting spacecraft in-situ and the data they collect on the Earth itself . Originally released as a Unity web player interactive , it has undergone a number of iterations including the mobile app `` Earth Now '' .   It lets users monitor earth 's vital signs , such as sea level height , atmospheric carbon dioxide concentration and Antarctic ozone . Trace the movement of water around the globe using the gravity map from NASA 's GRACE satellites . Spot volcanic eruptions and forest fires using the carbon monoxide vital sign . Check out the hottest and coldest locations on Earth with the global surface temperature map.It also displays the location of all of NASA 's operating Earth-observing missions in real time and lets you compare them in size to a scientist or a school bus .