query: Climate sensitivity can be calculated empirically by comparing past temperature change to natural forcings at the time.

positive: Climate sensitivity Climate sensitivity is the equilibrium temperature change in response to changes of the radiative forcing . Therefore , climate sensitivity depends on the initial climate state , but potentially can be accurately inferred from precise palaeoclimate data . Slow climate feedbacks , especially changes of ice sheet size and atmospheric CO2 , amplify the total Earth system sensitivity by an amount that depends on the time scale considered .   Although climate sensitivity is usually used in the context of radiative forcing by carbon dioxide ( CO2 ) , it is thought of as a general property of the climate system : the change in surface air temperature ( ΔTs ) following a unit change in radiative forcing ( RF ) , and thus is expressed in units of ° C / ( W/m2 ) . For this to be useful , the measure must be independent of the nature of the forcing ( e.g. from greenhouse gases or solar variation ) ; to first order this is indeed found to be so .   The climate sensitivity specifically due to is often expressed as the temperature change in ° C associated with a doubling of the concentration of carbon dioxide in Earth 's atmosphere .   For coupled atmosphere-ocean global climate models ( e.g. CMIP5 ) the climate sensitivity is an emergent property : it is not a model parameter , but rather a result of a combination of model physics and parameters . By contrast , simpler energy-balance models may have climate sensitivity as an explicit parameter .   The terms represented in the equation relate radiative forcing ( RF ) to linear changes in global surface temperature change ( ΔTs ) via the climate sensitivity λ .   It is also possible to estimate climate sensitivity from observations ; however , this is difficult due to uncertainties in the forcing and temperature histories .

negative: Climate change Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time ( i.e. , decades to millions of years ) . Climate change may refer to a change in average weather conditions , or in the time variation of weather around longer-term average conditions ( i.e. , more or fewer extreme weather events ) . Climate change is caused by factors such as biotic processes , variations in solar radiation received by Earth , plate tectonics , and volcanic eruptions . Certain human activities have been identified as primary causes of ongoing climate change , often referred to as global warming .   Scientists actively work to understand past and future climate by using observations and theoretical models . A climate record -- extending deep into the Earth 's past -- has been assembled , and continues to be built up , based on geological evidence from borehole temperature profiles , cores removed from deep accumulations of ice , floral and faunal records , glacial and periglacial processes , stable-isotope and other analyses of sediment layers , and records of past sea levels . More recent data are provided by the instrumental record . General circulation models , based on the physical sciences , are often used in theoretical approaches to match past climate data , make future projections , and link causes and effects in climate change .

negative: Attribution of recent climate change Attribution of recent climate change is the effort to scientifically ascertain mechanisms responsible for recent climate changes on Earth , commonly known as ` global warming ' . The effort has focused on changes observed during the period of instrumental temperature record , when records are most reliable ; particularly in the last 50 years , when human activity has grown fastest and observations of the troposphere have become available . The dominant mechanisms are anthropogenic , i.e. , the result of human activity . They are :  increasing atmospheric concentrations of greenhouse gases  global changes to land surface , such as deforestation  increasing atmospheric concentrations of aerosols .   There are also natural mechanisms for variation including climate oscillations , changes in solar activity , and volcanic activity .   According to the Intergovernmental Panel on Climate Change ( IPCC ) , it is `` extremely likely '' that human influence was the dominant cause of global warming between 1951 and 2010 . The IPCC defines `` extremely likely '' as indicating a probability of 95 to 100 % , based on an expert assessment of all the available evidence .   Multiple lines of evidence support attribution of recent climate change to human activities :  A basic physical understanding of the climate system : greenhouse gas concentrations have increased and their warming properties are well-established .  Historical estimates of past climate changes suggest that the recent changes in global surface temperature are unusual .  Computer-based climate models are unable to replicate the observed warming unless human greenhouse gas emissions are included .  Natural forces alone ( such as solar and volcanic activity ) can not explain the observed warming .   The IPCC 's attribution of recent global warming to human activities is a view shared by the scientific community , and is also supported by 196 other scientific organizations worldwide ( see also : scientific opinion on climate change ) .

negative: Climate change feedback Climate change feedback is important in the understanding of global warming because feedback processes may amplify or diminish the effect of each climate forcing , and so play an important part in determining the climate sensitivity and future climate state . Feedback in general is the process in which changing one quantity changes a second quantity , and the change in the second quantity in turn changes the first . Positive feedback amplifies the change in the first quantity while negative feedback reduces it .   The term `` forcing '' means a change which may `` push '' the climate system in the direction of warming or cooling . An example of a climate forcing is increased atmospheric concentrations of greenhouse gases . By definition , forcings are external to the climate system while feedbacks are internal ; in essence , feedbacks represent the internal processes of the system . Some feedbacks may act in relative isolation to the rest of the climate system ; others may be tightly coupled ; hence it may be difficult to tell just how much a particular process contributes . Forcings , feedbacks and the dynamics of the climate system determine how much and how fast the climate changes . The main positive feedback in global warming is the tendency of warming to increase the amount of water vapor in the atmosphere , which in turn leads to further warming . The main negative feedback comes from the Stefan -- Boltzmann law , the amount of heat radiated from the Earth into space changes with the fourth power of the temperature of Earth 's surface and atmosphere .   Some observed and potential effects of global warming are positive feedbacks , which contribute directly to further global warming . The Intergovernmental Panel on Climate Change 's ( IPCC ) Fourth Assessment Report states that `` Anthropogenic warming could lead to some effects that are abrupt or irreversible , depending upon the rate and magnitude of the climate change . ''

negative: Orbital forcing Orbital forcing is the effect on climate of slow changes in the tilt of the Earth 's axis and shape of the orbit ( see Milankovitch cycles ) . These orbital changes change the total amount of sunlight reaching the Earth by up to 25 % at mid-latitudes ( from 400 to 500 Wm − 2 at latitudes of 60 degrees ) . In this context , the term `` forcing '' signifies a physical process that affects the Earth 's climate .   This mechanism is believed to be responsible for the timing of the ice age cycles . A strict application of the Milankovitch theory does not allow the prediction of a `` sudden '' ice age ( rapid being anything under a century or two ) , since the fastest orbital period is about 20,000 years . The timing of past glacial periods coincides very well with the predictions of the Milankovitch theory , and these effects can be calculated into the future .

negative: Proxy (climate) In the study of past climates ( `` paleoclimatology '' ) , climate proxies are preserved physical characteristics of the past that stand in for direct meteorological measurements and enable scientists to reconstruct the climatic conditions over a longer fraction of the Earth 's history . Reliable global records of climate only began in the 1880s , and proxies provide the only means for scientists to determine climatic patterns before record-keeping began .   Examples of proxies include ice cores , tree rings , sub-fossil pollen , boreholes , corals , lake and ocean sediments , and carbonate speleothems . The character of deposition or rate of growth of the proxies ' material has been influenced by the climatic conditions of the time in which they were laid down or grew . Chemical traces produced by climatic changes , such as quantities of particular isotopes , can be recovered from proxies . Some proxies , such as gas bubbles trapped in ice , enable traces of the ancient atmosphere to be recovered and measured directly to provide a history of fluctuations in the composition of the Earth 's atmosphere . To produce the most precise results , systematic cross-verification between proxy indicators is necessary for accuracy in readings and record-keeping .   Proxies can be combined to produce temperature reconstructions longer than the instrumental temperature record and can inform discussions of global warming . The distribution of proxy records , just like the instrumental record , is not at all uniform , with more records in the northern hemisphere .

negative: Cloud feedback Cloud feedback is the coupling between cloudiness and surface air temperature where a surface air temperature change leads to a change in clouds , which could then amplify or diminish the initial temperature perturbation . Cloud feedbacks can affect the magnitude of internally generated climate variability or they can affect the magnitude of climate change resulting from external radiative forcings .   Global warming is expected to change the distribution and type of clouds . Seen from below , clouds emit infrared radiation back to the surface , and so exert a warming effect ; seen from above , clouds reflect sunlight and emit infrared radiation to space , and so exert a cooling effect . Cloud representations vary among global climate models , and small changes in cloud cover have a large impact on the climate . Differences in planetary boundary layer cloud modeling schemes can lead to large differences in derived values of climate sensitivity . A model that decreases boundary layer clouds in response to global warming has a climate sensitivity twice that of a model that does not include this feedback . However , satellite data show that cloud optical thickness actually increases with increasing temperature . Whether the net effect is warming or cooling depends on details such as the type and altitude of the cloud ; details that are difficult to represent in climate models .

negative: Climate Climate is the statistics of weather , usually over a 30-year interval . It is measured by assessing the patterns of variation in temperature , humidity , atmospheric pressure , wind , precipitation , atmospheric particle count and other meteorological variables in a given region over long periods of time . Climate differs from weather , in that weather only describes the short-term conditions of these variables in a given region .   A region 's climate is generated by the climate system , which has five components : atmosphere , hydrosphere , cryosphere , lithosphere , and biosphere .   The climate of a location is affected by its latitude , terrain , and altitude , as well as nearby water bodies and their currents . Climates can be classified according to the average and the typical ranges of different variables , most commonly temperature and precipitation . The most commonly used classification scheme was the Köppen climate classification . The Thornthwaite system , in use since 1948 , incorporates evapotranspiration along with temperature and precipitation information and is used in studying biological diversity and how climate change affects it . The Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region .   Paleoclimatology is the study of ancient climates . Since direct observations of climate are not available before the 19th century , paleoclimates are inferred from proxy variables that include non-biotic evidence such as sediments found in lake beds and ice cores , and biotic evidence such as tree rings and coral . Climate models are mathematical models of past , present and future climates . Climate change may occur over long and short timescales from a variety of factors ; recent warming is discussed in global warming . Global warming results in redistributions . For example , `` a 3 ° C change in mean annual temperature corresponds to a shift in isotherms of approximately 300 -- 400 km in latitude ( in the temperate zone ) or 500 m in elevation . Therefore , species are expected to move upwards in elevation or towards the poles in latitude in response to shifting climate zones '' .

negative: Pseudoproxy A pseudoproxy is a synthetic dataset used in paleoclimatology to test methods of reconstruction of global or hemispherical climate change from temperature records , developed for reconstructing the temperature record of the past 1000 years using proxies for periods before the instrumental temperature record . In May 2002 Michael E. Mann and Scott Rutherford published a paper introducing this method of adding artificial noise to actual temperature records or to climate model simulations to produce what they called `` pseudoproxies '' . When the reconstruction algorithms were used with these pseudoproxies , the result was then compared with the original record or simulation to see how closely it had been reconstructed . They discussed the issue that regression methods of reconstruction tended to underestimate the amplitude of variation .

negative: Geologic temperature record The Geologic temperature record are changes in Earth 's environment as determined from geologic evidence on multi-million to billion ( 109 ) year time scales . The study of past temperatures provides an important paleoenvironmental insight because it is a crucial component of the climate and oceanography of the time .

negative: Homogenization (climate) Homogenization in climate research means the removal of non-climatic changes . Next to changes in the climate itself , raw climate records also contain non-climatic jumps and changes for example due to relocations or changes in instrumentation . The most used principle to remove these inhomogeneities is the relative homogenization approach in which a candidate stations is compared to a reference time series based on one or more neighboring stations . The candidate and reference station ( s ) experience about the same climate , non-climatic changes that happen only in one station can thus be identified and removed .

negative: Climate state Climate state describes a state of climate on Earth and similar terrestrial planets based on a thermal energy budget , such as the greenhouse or icehouse climate state .   The main climate state change is between periodical glacial and interglacial cycles in Earth history , studied from climate proxies . The climate system is responding to the current climate forcing and adjusts following climate sensitivity to reach a climate equilibrium , Earth 's energy balance . Model simulations suggest that the current interglacial climate state will continue for at least another 100,000 years , due to emissions - including complete deglaciation of the Northern Hemisphere .

negative: Abrupt climate change An abrupt climate change occurs when the climate system is forced to transition to a new climate state at a rate that is determined by the climate system energy-balance , and which is more rapid than the rate of change of the external forcing . Past events include the end of the Carboniferous Rainforest Collapse , Younger Dryas , Dansgaard-Oeschger events , Heinrich events and possibly also the Paleocene-Eocene thermal maximum . The term is also used within the context of global warming to describe sudden climate change that is detectable over the time-scale of a human lifetime . One proposed reason for the observed abrupt climate change is that feedback loops within the climate system both enhance small perturbations and cause a variety of stable states .   Timescales of events described as ` abrupt ' may vary dramatically . Changes recorded in the climate of Greenland at the end of the Younger Dryas , as measured by ice-cores , imply a sudden warming of + 10 C-change within a timescale of a few years . Other abrupt changes are the + 4 C-change on Greenland 11,270 years ago or the abrupt + 6 C-change warming 22,000 years ago on Antarctica . By contrast , the Paleocene-Eocene thermal maximum may have initiated anywhere between a few decades and several thousand years . Finally , Earth Systems models project that under ongoing greenhouse gas emissions as early as 2047 , the Earth 's near surface temperature could depart from the range of variability in the last 150 years , affecting over 3 billion people and most places of great species diversity on Earth .

negative: Climate variability Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. In the time since the industrial revolution the climate has increasingly been affected by human activities that are causing global warming and climate change.The climate system receives nearly all of its energy from the sun. The climate system also radiates energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth's energy budget. When the incoming energy is greater than the outgoing energy, earth's energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling. The energy moving through Earth's climate system finds expression in weather, varying on geographic scales and time. Long-term averages and variability of weather in a region constitute the region's climate. Such changes can be the result of "internal variability", when natural processes inherent to the various parts of the climate system alter the distribution of energy. Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation. Climate variability can also result from external forcing, when events outside of the climate system's components nonetheless produce changes within the system. Examples include changes in solar output and volcanism. Climate variability has consequences for sea level changes, plant life, and mass extinctions; it also affects human societies.

negative: Tipping points in the climate system A tipping point in the climate system is a threshold that, when exceeded, can lead to large changes in the state of the system. Potential tipping points have been identified in the physical climate system, in impacted ecosystems, and sometimes in both. For instance, feedback from the global carbon cycle is a driver for the transition between glacial and interglacial periods, with orbital forcing providing the initial trigger. Earth's geologic temperature record includes many more examples of geologically rapid transitions between different climate states.Climate tipping points are of particular interest in reference to concerns about global warming in the modern era. Possible tipping point behaviour has been identified for the global mean surface temperature by studying self-reinforcing feedbacks and the past behavior of Earth's climate system. Self-reinforcing feedbacks in the carbon cycle and planetary reflectivity could trigger a cascading set of tipping points that lead the world into a hothouse climate state.Large-scale components of the Earth system that may pass a tipping point have been referred to as tipping elements. Tipping elements are found in the Greenland and Antarctic ice sheets, possibly causing tens of meters of sea level rise. These tipping points are not always abrupt. For example, at some level of temperature rise the melt of a large part of the Greenland ice sheet and/or West Antarctic Ice Sheet will become inevitable; but the ice sheet itself may persist for many centuries. Some tipping elements, like the collapse of ecosystems, are irreversible.

negative: History of climate change science The history of the scientific discovery of climate change began in the early 19th century when ice ages and other natural changes in paleoclimate were first suspected and the natural greenhouse effect first identified . In the late 19th century , scientists first argued that human emissions of greenhouse gases could change the climate . Many other theories of climate change were advanced , involving forces from volcanism to solar variation . In the 1960s , the warming effect of carbon dioxide gas became increasingly convincing . Some scientists also pointed out that human activities that generated atmospheric aerosols ( e.g. , `` pollution '' ) could have cooling effects as well . During the 1970s , scientific opinion increasingly favored the warming viewpoint . By the 1990s , as a result of improving fidelity of computer models and observational work confirming the Milankovitch theory of the ice ages , a consensus position formed : greenhouse gases were deeply involved in most climate changes and human caused emissions were bringing discernible global warming . Since the 1990s , scientific research on climate change has included multiple disciplines and has expanded . Research has expanded our understanding of causal relations , links with historic data and ability to model climate change numerically . Research during this period has been summarized in the Assessment Reports by the Intergovernmental Panel on Climate Change .   Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years . It may be a change in average weather conditions , or in the distribution of weather around the average conditions ( such as more or fewer extreme weather events ) . Climate change is caused by factors that include oceanic processes ( such as oceanic circulation ) , biotic processes , variations in solar radiation received by Earth , plate tectonics and volcanic eruptions , and human-induced alterations of the natural world . The latter effect is currently causing global warming , and `` climate change '' is often used to describe human-specific impacts .

negative: Effects of climate change on terrestrial animals Climate change has had a significant direct effect on terrestrial animals , by being a major driver of the processes of speciation and extinction . The best known example of this is the Carboniferous Rainforest Collapse which occurred 350 million years ago . This event decimated amphibian populations and spurred on the evolution of reptiles .   Climate change is a natural event that has occurred throughout history . However , with the recent increased emission of CO2 in the Earth 's atmosphere , abrupt climate change has occurred . It has been hypothesized that anthropogenic greenhouse gas forcing has significantly influenced global climate since about 8000 before present ( Van Hoof 2006 ) .   Animals have had specific responses to climate change . Species respond to climate changes by migration , adaptation , or if neither of those occur , death . These migrations can sometimes follow an animal 's preferred temperature , elevation , soil , etc. , as said terrain moves due to climate change . Adaptation can be either genetic or phenological , and death can occur in a local population only ( extirpation ) or as an entire species , otherwise known as extinction .   Climate changes is projected to affect individual organisms , populations , species distributions and ecosystem composition and function both directly ( ex . Increased temperatures and changes in precipitation ) and indirectly ( through climate changing the intensity and frequency of disturbances such as wildfires and severe storms ) ( IPCC 2002 ) .   Every organism has a unique set of preferences or requirements , a niche and biodiversity has been tied to the diversity of animals ' niches . These can include or be affected by temperature , aridity , resource availability , habitat requirements , enemies , soil characteristics , competitors , and pollinators . Since the factors that compose a niche can be so complex and interconnected , the niches of many animals are bound to be affected by climate change ( Parmesan Yohe 2003 ) .   One study done by Camille Parmesan and Gary Yohe from University of Texas , Austin shows the global fingerprint of climate change on natural systems . The results of their global analysis of 334 species were recorded to demonstrate the correlation of patterns consistent with global climate change of the 20th century . Using the IPCC 's ( Intergovernmental Panel on Climate Change ) ` levels of confidence ' , this study proved significant nonrandom behavioral changes due to global climate change with very high confidence ( > 95 ) . Furthermore , an accuracy of 74-91 % change in species has displayed predicted change for species in response to climate change .

negative: Climate change policy of the United States Global climate change was first addressed in United States policy beginning in the early 1960s . The Environmental Protection Agency ( EPA ) defines climate change as `` any significant change in the measures of climate lasting for an extended period of time . '' Essentially , climate change includes major changes in temperature , precipitation , or wind patterns , as well as other effects , that occur over several decades or longer . Climate change policy in the US has transformed rapidly over the past twenty years and is being developed at both the state and federal level . The politics of global warming and climate change have polarized certain political parties and other organizations . This article focuses on climate change policy within the United States , as well as exploring the positions of various parties and the influences on policy making and environmental justice repercussions .

negative: Climate system Earth's climate arises from the interaction of five major climate system components: the atmosphere (air), the hydrosphere (water), the cryosphere (ice and permafrost), the lithosphere (earth's upper rocky layer) and the biosphere (living things). Climate is the average weather, typically over a period of 30 years, and is determined by a combination of processes in the climate system, such as ocean currents and wind patterns. Circulation in the atmosphere and oceans is primarily driven by solar radiation and transports heat from the tropical regions to regions that receive less energy from the Sun. The water cycle also moves energy throughout the climate system. In addition, different chemical elements, necessary for life, are constantly recycled between the different components. The climate system can change due to internal variability and external forcings. These external forcings can be natural, such as variations in solar intensity and volcanic eruptions, or caused by humans. Accumulation of heat-trapping greenhouse gases, mainly being emitted by people burning fossil fuels, is causing global warming. Human activity also releases cooling aerosols, but their net effect is far less than that of greenhouse gases. Changes can be amplified by feedback processes in the different climate system components.

negative: Climate change (general concept) Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. In the time since the industrial revolution the climate has increasingly been affected by human activities that are causing global warming and climate change.The climate system receives nearly all of its energy from the sun. The climate system also radiates energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth\'s energy budget. When the incoming energy is greater than the outgoing energy, earth\'s energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling.\nThe energy moving through Earth\'s climate system finds expression in weather, varying on geographic scales and time. Long-term averages and variability of weather in a region constitute the region\'s climate. Such changes can be the result of "internal variability", when natural processes inherent to the various parts of the climate system alter the distribution of energy. Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation. Climate variability can also result from external forcing, when events outside of the climate system\'s components nonetheless produce changes within the system. Examples include changes in solar output and volcanism.\nClimate variability has consequences for sea level changes, plant life, and mass extinctions; it also affects human societies.

negative: Coral in non-tropical regions The poleward migration of coral species refers to the phenomenon brought on by rising sea temperatures, wherein corals are colonising cooler climates in an attempt to circumvent coral bleaching, rising sea levels and ocean acidification. In the age of Anthropocene, the changing global climate has disrupted fundamental natural processes and brought about observable changes in the submarine sphere. Whilst coral reefs are bleaching in tropical areas like the Great Barrier Reef, even more striking, and perhaps more alarming; is the growth of tropical coral species in temperate regions, which has taken place over the past decade. Coral reefs are frequently compared to the "canaries in the coal mine," who were used by miners as an indicator of air quality. In much the same way, "coral reefs are sensitive to environmental changes that could damage other habitats in the future," meaning they will be the first to visually exhibit the true implications of global warming on the natural world.

negative: Climate change in Nevada Climate change in Nevada has been measured over the last century , with the average temperature in Elko , Nevada increasing by 0.6 F-change , and precipitation increasing by up to 20 % in many parts of the state . These past trends may or may not continue into the future .

negative: Paleoclimatology Paleoclimatology ( in British spelling , palaeoclimatology ) is the study of changes in climate taken on the scale of the entire history of Earth . It uses a variety of proxy methods from the Earth and life sciences to obtain data previously preserved within things such as rocks , sediments , ice sheets , tree rings , corals , shells and microfossils . It then uses the records to determine the past states of the Earth 's various climate regions and its atmospheric system . Studies of past changes in the environment and biodiversity often reflect on the current situation , specifically the impact of climate on mass extinctions and biotic recovery .

negative: Paleoclimate Modelling Intercomparison Project The Paleoclimate Modelling Intercomparison Project is a project , somewhat along the lines of AMIP or CMIP , to coordinate and encourage the systematic study of atmospheric general circulation models ( AGCMs ) and to assess their ability to simulate large climate changes such as those that occurred in the distant past . Project goals include identifying common responses of AGCMs to imposed paleoclimate `` boundary conditions , '' understanding the differences in model responses , comparing model results with paleoclimate data , and providing AGCM results for use in helping in the analysis and interpretation of paleoclimate data . PMIP is initially focussing on the mid-Holocene ( 6,000 years before present ) and the Last Glacial Maximum ( 21,000 yr BP ) because climatic conditions were remarkably different at those times , and because relatively large amounts of paleoclimate data exist for these periods . The major `` forcing '' factors are also relatively well known at these times . Some of the paleoclimate features simulated by models in previous studies seem consistent with paleoclimatic data , but others do not . One of the goals of PMIP is to determine which results are model-dependent . The PMIP experiments are limited to studying the equilibrium response of the atmosphere ( and such surface characteristics as snow cover ) to changes in boundary conditions ( e.g. , insolation , ice-sheet distribution , CO2 concentration , etc. . )

negative: List of large-scale temperature reconstructions of the last 2,000 years This list of large scale temperature reconstructions of the last 2,000 years includes climate reconstructions which have contributed significantly to the modern consensus on the temperature record of the past 2000 years .   The instrumental temperature record only covers the last 150 years at a hemispheric or global scale , and reconstructions of earlier periods are based on climate proxies . In an early attempt to show that climate had changed , Hubert Lamb 's 1965 paper generalised from temperature records of central England together with historical , botanical and archeological evidence to produce a qualitative estimate of temperatures in the north Atlantic region . Subsequent quantitative reconstructions used statistical techniques with various climate proxies to produce larger scale reconstructions . Tree ring proxies can give an annual resolution of extratropical regions of the northern hemisphere , and can be statistically combined with other sparser proxies to produce multiproxy hemispherical or global reconstructions .   Quantitative reconstructions have consistently shown earlier temperatures below the temperature levels reached in the late 20th century . This pattern as seen in was dubbed the hockey stick graph , and as of 2010 this broad conclusion was supported by more than two dozen reconstructions , using various statistical methods and combinations of proxy records , with variations in how flat the pre-20th century `` shaft '' appears .

negative: Historical climatology Historical climatology is the study of historical changes in climate and their effect on human history and development . This differs from paleoclimatology which encompasses climate change over the entire history of Earth . The study seeks to define periods in human history where temperature or precipitation varied from what is observed in the present day . The primary sources include written records such as sagas , chronicles , maps and local history literature as well as pictorial representations such as paintings , drawings and even rock art . The archaeological record is equally important in establishing evidence of settlement , water and land usage .

negative: Milutin Milanković Milutin Milanković ( Милутин Миланковић , pronounced -LSB- milǔtin milǎːnkɔʋitɕ -RSB- 28 May 1879 -- 12 December 1958 ) was a Serbian mathematician , astronomer , climatologist , geophysicist , civil engineer , doctor of technology , university professor and popularizer of science . Milanković gave two fundamental contributions to global science . The first contribution is the `` Canon of the Earth 's Insolation '' , which characterizes the climates of all the planets of the Solar system . The second contribution is the explanation of Earth 's long-term climate changes caused by changes in the position of the Earth in comparison to the Sun , now known as Milankovitch cycles . This explained the ice ages occurring in the geological past of the Earth , as well as the climate changes on the Earth which can be expected in the future . He founded planetary climatology by calculating temperatures of the upper layers of the Earth 's atmosphere as well as the temperature conditions on planets of the inner Solar system , Mercury , Venus , Mars , and the Moon , as well as the depth of the atmosphere of the outer planets . He demonstrated the interrelatedness of celestial mechanics and the Earth sciences , and enabled consistent transition from celestial mechanics to the Earth sciences and transformation of descriptive sciences into exact ones .

negative: Ecological forecasting Ecological forecasting uses knowledge of physics , ecology and physiology to predict how ecosystems will change in the future in response to environmental factors such as climate change . The ultimate goal of the approach is to provide people such as resource managers and designers of marine reserves with information that they can then use to respond , in advance , to future changes , a form of adaptation to global warming .   One of the most important environmental factors for organisms today is global warming . Most physiological processes are affected by temperature , and so even small changes in weather and climate can lead to large changes in the growth , reproduction and survival of animals and plants . The scientific consensus  is that the increase in atmospheric greenhouse gases due to human activity caused most of the warming observed since the start of the industrial era . These changes are in turn affecting human and natural ecosystems .   One major challenge is to predict where , when and with what magnitude changes are likely to occur so that we can mitigate or at least prepare for them . Ecological forecasting applies existing knowledge of how animals and plants interact with their physical environment to ask how changes in environmental factors might result in changes to the ecosystems as a whole .

negative: Radiative forcing Radiative forcing or climate forcing is the difference between insolation ( sunlight ) absorbed by the Earth and energy radiated back to space . Typically , radiative forcing is quantified at the tropopause in units of watts per square meter of the Earth 's surface . Positive forcing ( incoming energy exceeding outgoing energy ) warms the system , while negative forcing ( outgoing energy exceeding incoming energy ) cools it . Causes of radiative forcing include changes in insolation and the concentrations of radiatively active gases , commonly known as greenhouse gases and aerosols .

negative: Climate oscillation A climate oscillation or climate cycle is any recurring cyclical oscillation within global or regional climate , and is a type of climate pattern . These fluctuations in atmospheric temperature , sea surface temperature , precipitation or other parameters can be quasi-periodic , often occurring on inter-annual , multi-annual , decadal , multidecadal , century-wide , millennial or longer timescales . They are not perfectly periodic and a Fourier analysis of the data does not give a sharp spectrum .   A prominent example is the El Niño Southern Oscillation , involving sea surface temperatures along a stretch of the equatorial Central and East Pacific Ocean and the western coast of tropical South America , but which affects climate worldwide .   Records of past climate conditions are recovered through geological examination of proxies , found in glacier ice , sea bed sediment , tree ring studies or otherwise .

negative: Effects of global warming The effects of global warming are the environmental and social changes caused ( directly or indirectly ) by human emissions of greenhouse gases . There is a scientific consensus that climate change is occurring , and that human activities are the primary driver . Many impacts of climate change have already been observed , including glacier retreat , changes in the timing of seasonal events ( e.g. , earlier flowering of plants ) , and changes in agricultural productivity .   Future effects of climate change will vary depending on climate change policies and social development . The two main policies to address climate change are reducing human greenhouse gas emissions ( climate change mitigation ) and adapting to the impacts of climate change . Geoengineering is another policy option .   Near-term climate change policies could significantly affect long-term climate change impacts . Stringent mitigation policies might be able to limit global warming ( in 2100 ) to around 2 ° C or below , relative to pre-industrial levels . Without mitigation , increased energy demand and extensive use of fossil fuels might lead to global warming of around 4 ° C. Higher magnitudes of global warming would be more difficult to adapt to , and would increase the risk of negative impacts .

negative: Gas duster Gas duster , also known as canned air or compressed air , is a product used for cleaning or dusting electronic equipment and other sensitive devices that can not be cleaned using water . The products are most often a can that , when a trigger is pressed , blasts a stream of compressed gas through a nozzle . Despite the name `` canned air '' , the cans actually contain gases that are compressable into liquids . Air on the contrary , can not be compressed into liquid at any pressure since the critical temperatures of air components ( -146.9 C for nitrogen ; -118.6 C for oxygen ) are much beyond normal handling temperatures . Duster gases are such as 1,1-difluoroethane , 1,1,1-trifluoroethane , or 1,1,1,2  - tetrafluoroethane . Hydrocarbons , like butane , were often used in the past , but their flammable nature forced manufacturers to use fluorocarbons . When inhaled , gas duster fumes may produce psychoactive effects and may be harmful to health .

negative: Effects of climate change The effects of climate change may refer to :  Effects of global warming , the effects of current climate change  Historical impacts of climate change , during the early evolution and history of humans , prior to current global warming


query: Many lines of evidence, including simple accounting, demonstrate beyond a shadow of a doubt that the increase in atmospheric CO2 is due to human fossil fuel burning.

positive: Scientific consensus on climate change There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports.  Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors.

positive: Greenhouse gas A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about -18 ° C , rather than the present average of 15 ° C . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect .   Human activities since the beginning of the Industrial Revolution ( taken as the year 1750 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . Anthropogenic carbon dioxide emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , along with deforestation , soil erosion and animal agriculture .   It has been estimated that if greenhouse gas emissions continue at the present rate , Earth 's surface temperature could exceed historical values as early as 2047 , with potentially harmful effects on ecosystems , biodiversity and the livelihoods of people worldwide . Recent estimates suggest that on the current emissions trajectory the Earth could pass a threshold of 2 ° C global warming , which the United Nations ' IPCC designated as the upper limit to avoid `` dangerous '' global warming , by 2036 .

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 .

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 rift Carbon rift is a theory attributing the input and output of carbon into the environment to human capitalistic systems . This is a derivative of Karl Marx 's concept of metabolic rift . In practical terms , increased commodity production demands that greater levels of carbon dioxide ( or CO2 ) be emitted into the biosphere via fossil fuel consumption . Carbon rift theory states that this ultimately disrupts the natural carbon cycle and that this `` rift '' has adverse effects on nearly every aspect of life . Many of the specifics regarding how this metabolic carbon rift interacts with capitalism are proposed by Brett Clark and Richard York in a 2005 article titled `` Carbon Metabolism : Global capitalism , climate change , and the biospheric rift '' in the journal Theory and Society . Researchers such as Jean P. Sapinski of the University of Oregon claim that , despite increased interest in closing the carbon rift , it is projected that as long as capitalism continues , there is little hope of reducing the rift .   Both deforestation and the emission of greenhouse gases have been linked to increased atmospheric CO2 levels . Carbon rift theory states that these are the result of human production through capitalistic systems . There are proposed solutions to climate change such as geoengineering proposed in the December 2015 Paris Agreement . However , some argue that the capitalist mode of production is at fault for the emission of greenhouse gas and that solutions must be found to this issue before climate change itself can be addressed .   Carbon rift theory , while rarely criticized directly , often indirectly receives criticism regarding the underlying causes of climate change and attributing the stated effects to alternative explanations for climate change , instead of as a result of human activity . Such explanations include the Chaotic Solar System Theory and that increased water vapor is responsible for climate change .

negative: Carbon cycle re-balancing The carbon cycle is the process by which carbon is exchanged between the four reservoirs of carbon : the biosphere , the earth , the air and water . Exchanges take place in several ways , including respiration , transpiration , combustion , and decomposition . The carbon balance , or carbon budget , is the balance of exchange between the four reservoirs .   Debate about 're - balancing the carbon cycle ' arises from a concern that use of fossil fuels , which has accelerated since the start of the industrial revolution , has caused carbon to accumulate in the atmosphere . Levels of CO2 in the atmosphere are estimated to have risen from 280 ppm to almost 400 ppm since 1800 and this is linked to global warming . It is therefore argued that the carbon cycle should be re-balanced by reducing the amount of CO2 in the atmosphere .   ` Carbon cycle re-balancing ' is a useful name for a group of environmental policies listed below . The name gives a specific reason for adopting these policies . Related names , including pleas for sustainable development and participation in the green movement are politics-based rather than science-based .   Carbon offset - for example by photosynthesis ( e.g. in new forests )  Carbon capture and storage - extraction of CO2 and placing it underground or underwater  Carbon capture and transformation - extraction of CO2 and reacting it with hydrogen via renewable energy electrolysis to create methane as an energy store/carrier . Low to neutral cycle  Sustainable energy - a shift from fossil fuels energy to wind power and solar power  Nuclear power - as an alternative to fossil fuels  Sustainable design - to reduce inputs and outputs of energy  Sustainable transport - to reduce reliance on fossil fuels   Burning domestic refuse to generate power can be promoted as a recycling , and therefore sustainable , policy . But from a carbon cycle re-balancing standpoint it is better to compost as much domestic refuse as possible .

negative: Fossil fuel power station A fossil fuel power station is a power station which burns fossil fuel such as coal , natural gas , or petroleum to produce electricity . Central station fossil fuel power plants are designed on a large scale for continuous operation . In many countries , such plants provide most of the electrical energy used . Fossil fuel power stations have machinery to convert the heat energy of combustion into mechanical energy , which then operates an electrical generator . The prime mover may be a steam turbine , a gas turbine or , in small plants , a reciprocating internal combustion engine . All plants use the energy extracted from expanding gas , either steam or combustion gases . Very few MHD generators have been built which directly convert the energy of hot , moving water into electricity . MHD means Magnetohydrodynamics , which is the study of the magnetic properties of electrically conducting fluids . Examples of such magnetofluids include plasmas , liquid metals , salt water and electrolytes .   By-products of thermal power plant operation must be considered in their design and operation . Waste heat energy , which remains due to the finite efficiency of the Carnot , Rankine , or Diesel power cycle , is released directly to the atmosphere or river/lake water , or indirectly to the atmosphere using a cooling tower with river or lake water used as a cooling medium . The flue gas from combustion of the fossil fuels is discharged to the air . This gas contains carbon dioxide and water vapor , as well as other substances such as nitrogen oxides ( NOx ) , sulfur oxides ( SOx ) , mercury , traces of other metals , and , for coal-fired plants , fly ash . Solid waste ash from coal-fired boilers must also be removed . Some coal ash can be recycled for building materials .   Fossil fueled power stations are major emitters of carbon dioxide ( CO2 ) , a greenhouse gas which according to a consensus opinion of scientific organisations is a contributor to global warming . The results of a recent study show that the net income available to shareholders of large companies could see a significant reduction from the greenhouse gas emissions liability related to only natural disasters in the U.S. from a single coal-fired power plant . However , as of 2015 , no such cases have awarded damages in the U.S. Per unit of electric energy , brown coal emits nearly two times as much CO2 as natural gas , and black coal emits somewhat less than brown . Carbon capture and storage of emissions is not currently available .

negative: Low-carbon emission The main components of automobile exhaust are carbon dioxide ( CO2 ) and water vapor ( H2O ) . Carbon dioxide is the most important anthropogenic greenhouse gas ( GHG ) and the most significant Greenhouse Gas emitted in the U.S. ( with 82-84 % of all U.S. emissions ) . Increases in carbon dioxide concentration are due primarily to fossil fuel use and land-use change .   The CO2 emission standards can be referred to the fuel or to the vehicle :   The European Union is moving towards fuel mandatory CO2 standards and USA has reflected it in the Greenhouse Gas Score .  There are information , but no mandatory , standards for CO2 limits in vehicle ( engine ) emissions , excepting some state regulations ( i.e. California ) . See hybrid vehicles .   CO2 mass emission in vehicles is measured in g/km ( g/mi * 0.621371192 = g/km ) .

negative: Recycled fuel Fuel made of residues as CO2 produced by using a primary fuel .   For example , CO2 pollution in the atmosphere , produced by petrol burning or other sources , can be extracted to produce fuel through an artificial photosynthesis based in nanotechnology , which helps to mitigate pollution , climate change and energy issues .

negative: Deforestation and climate change Deforestation is one of the main contributors to climate change . It is the second largest anthropogenic source of carbon dioxide to the atmosphere , after fossil fuel combustion . Deforestation and forest degradation contribute to atmospheric greenhouse gas emissions through combustion of forest biomass and decomposition of remaining plant material and soil carbon . It used to account for more than 20 % of carbon dioxide emissions , but it 's currently somewhere around the 10 % mark . By 2008 , deforestation was 12 % of total , or 15 % if peatlands are included . These proportions are likely to have fallen since given the continued rise of fossil fuel use .   Averaged over all land and ocean surfaces , temperatures warmed roughly 1.53 ° F ( 0.85 ° C ) between 1880 and 2012 , according to the Intergovernmental Panel on Climate Change . In the Northern Hemisphere , 1983 to 2012 were the warmest 30-year period of the last 1400 years .

negative: Greenhouse effect The greenhouse effect is the process by which radiation from a planet 's atmosphere warms the planet 's surface to a temperature above what it would be without its atmosphere .   If a planet 's atmosphere contains radiatively active gases ( i.e. , greenhouse gases ) the atmosphere will radiate energy in all directions . Part of this radiation is directed towards the surface , warming it . The downward component of this radiation -- that is , the strength of the greenhouse effect -- will depend on the atmosphere 's temperature and on the amount of greenhouse gases that the atmosphere contains .   On Earth , the atmosphere is warmed by absorption of infrared thermal radiation from the underlying surface ( heated by the sun ) , absorption of shorter wavelength radiant energy from the sun , and convective heat fluxes from the surface . Greenhouse gases in the atmosphere radiate energy , some of which is directed to the surface and lower atmosphere . The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect .   Earth 's natural greenhouse effect is critical to supporting life . Human activities , primarily the burning of fossil fuels and clearing of forests , have intensified the natural greenhouse effect , causing global warming .   The mechanism is named after a faulty analogy with the effect of solar radiation passing through glass and warming a greenhouse . The way a greenhouse retains heat is fundamentally different , as a greenhouse works by reducing airflow and retaining warm air inside the structure .

negative: Fossil Fuel Beta Fossil Fuel Beta ( FFß ) measures the percent change in excess , i.e. , market-adjusted , stock returns for every 1 percent increase in fossil fuel prices . If , for example , a company ( or industry ) has an FFß of -- 0.20 , then a 1 percent increase in fossil fuel prices should produce , on average , a 0.2 % decline in the firm 's stock price over and above the impact arising from fossil fuel price swing on the stock market as a whole . ( Conversely , a 1 percent decrease in fossil fuel prices should produce , on average , an equivalent increase in stock price . )   Converting the FFß into a hypothetical ` EPS-equivalent , ' based on , say , a 10 percent change in fossil fuel prices , it is possible to compare earnings-at-risk for individual companies with their competitors , or even industries with each other .

negative: David Archer (scientist) David Archer is a computational ocean chemist , and has been a professor at the Geophysical Sciences department at the University of Chicago since 1993 . He has published research on the carbon cycle of the ocean and the sea floor . He has worked on the history of atmospheric CO2 concentration , the expectation of fossil fuel CO2 over geologic time scales in the future , and the impact of CO2 on future ice age cycles , ocean methane hydrate decomposition , and coral reefs .   He is a contributor to the RealClimate blog .

negative: List of countries by carbon dioxide emissions -RSB-   This is a list of sovereign states and territories by carbon dioxide emissions due to certain forms of human activity , based on the EDGAR database created by European Commission and Netherlands Environmental Assessment Agency released in 2015 . The following table lists the 2015 annual emissions estimates ( in thousands of tonnes ) along with a list of emissions per capita ( in tonnes of per year ) from same source . The data only considers carbon dioxide emissions from the burning of fossil fuels and cement manufacture , but not emissions from land use , land-use change and forestry . Emissions from international shipping or bunker fuels are also not included in national figures , which can make a huge difference for small countries with important ports .  The top 10 largest emitter countries account for 67.6 % of the world total . Other powerful , more potent greenhouse gases , including methane , are not included in this data .

negative: Reasonable doubt Reasonable doubt is a term used in jurisdiction of Anglo-Saxon countries . Evidence that is beyond reasonable doubt is the standard of evidence required to validate a criminal conviction in most adversarial legal systems .   Generally , prosecutors bear the burden of proof and are required to prove their version of events to this standard . This means that the proposition being presented by the prosecution must be proven to the extent that there could be no `` reasonable doubt '' in the mind of a `` reasonable person '' that the defendant is guilty . There can still be a doubt , but only to the extent that it would not affect a reasonable person 's belief regarding whether or not the defendant is guilty . Beyond `` the shadow of a doubt '' is sometimes used interchangeably with beyond reasonable doubt , but this extends beyond the latter , to the extent that it may be considered an impossible standard . The term `` reasonable doubt '' is therefore used .   If doubt does affect a `` reasonable person 's '' belief that the defendant is guilty , the jury is not satisfied beyond `` reasonable doubt '' . The precise meaning of words such as `` reasonable '' and `` doubt '' are usually defined within jurisprudence of the applicable country . A related idea is Blackstone 's formulation `` It is better that ten guilty persons escape than that one innocent suffer '' .   Beyond a reasonable doubt is the highest burden of proof in any court in the United States . Criminal cases must be proven beyond a reasonable doubt .

negative: The Moral Case for Fossil Fuels The Moral Case for Fossil Fuels is a 2014 book by American energy theorist Alex Epstein , in which Epstein argues that , although sometimes labeled as `` immoral , '' the use of fossil fuels dramatically improves the overall progress of humanity , and improves life expectancy and income . The book was a New York Times and Wall Street Journal bestseller .

negative: History of sustainability The history of sustainability traces human-dominated ecological systems from the earliest civilizations to the present . This history is characterized by the increased regional success of a particular society , followed by crises that were either resolved , producing sustainability , or not , leading to decline .   In early human history , the use of fire and desire for specific foods may have altered the natural composition of plant and animal communities . Between 8,000 and 10,000 years ago , agrarian communities emerged which depended largely on their environment and the creation of a `` structure of permanence '' .   The Western industrial revolution of the 18th to 19th centuries tapped into the vast growth potential of the energy in fossil fuels . Coal was used to power ever more efficient engines and later to generate electricity . Modern sanitation systems and advances in medicine protected large populations from disease . In the mid-20th century , a gathering environmental movement pointed out that there were environmental costs associated with the many material benefits that were now being enjoyed . In the late 20th century , environmental problems became global in scale . The 1973 and 1979 energy crises demonstrated the extent to which the global community had become dependent on non-renewable energy resources .   In the 21st century , there is increasing global awareness of the threat posed by the human-induced enhanced greenhouse effect , produced largely by forest clearing and the burning of fossil fuels .

negative: Cap and Share Cap and Share was originally developed by Feasta ( the Foundation for the Economics of Sustainability ) and is a regulatory and economic framework for controlling the use of fossil fuels in relation to climate stabilisation . Accepting that climate change is a global problem and that there is a need to cap and reduce greenhouse gas emissions globally , the philosophy of Cap and Share maintains that the earth 's atmosphere is a fundamental common resource . Consequently , it is argued , each individual should get an equal share of the benefits from the limited amount of fossil fuels that will have to be burned and their emissions released into the atmosphere in the period until the atmospheric concentration of greenhouse gases has been stabilised at a safe level .

negative: Phenalene Phenalene is a polycyclic aromatic hydrocarbon ( PAH ) . Like many PAHs , it is an atmospheric pollutant formed during the combustion of fossil fuels .

negative: Direct carbon fuel cell A Direct Carbon Fuel Cell ( DCFC ) is a fuel cell that uses a carbon rich material as a fuel such as bio-mass or coal . The cell produces energy by combining carbon and oxygen , which releases carbon dioxide as a by-product . It also called coal fuel cells ( CFCs ) , carbon-air fuel cells ( CAFCs ) , direct carbon/coal fuel cells ( DCFCs ) , and DC-SOFC .   The total reaction of the cell is C + O2 → CO2 .  The process in half cell notation :  Anode : C + 2 O2 − → CO2 + 4 e −  Cathode : O2 + 4 e − → 2 O2 −   Despite this release of carbon dioxide , the direct carbon fuel cell is more environmentally friendly than traditional carbon burning techniques . Due to its higher efficiency , it requires less carbon to produce the same amount of energy . Also , because pure carbon dioxide is emitted , carbon capture techniques are much cheaper than for conventional power stations . Utilized carbon can be in the form of coal , coke , char , or a non-fossilized source of carbon .   At least four types of DCFC exist :  The first one is based on the Solid oxide fuel cell ( SOFC ) concept .   Overall reaction in the solid oxide electrolyte based DCFC  C + O2 → CO2 .   Anode reaction   <Direct electrochemical oxidation path>   C + 2O2 − → CO2 + 4e −   C + O2 − → CO + 2e −   <Indirect electrochemical oxidation path>   CO + O2 − → CO2 + 2e −   <Boudouard reaction:indirect chemical reaction path>   C + CO2 → 2CO   Cathode reaction   O2 + 4e − → 2O2 −   The second one is molten hydroxides fuel cell . William W. Jacques obtained an US Patent 555,511 in this type of fuel cell in 1896 . Prototypes have been demonstrated by the research group , SARA , Inc. .  The third one is based on the Molten Carbonate Fuel Cell ( MCFC ) concept . William W. Jacques obtained a Canadian patent in this type of fuel cell in 1897 . It has been developed further at the Lawrence Livermore Laboratory .  The fourth is a molten tin anode solid oxide fuel cell design , which utilizes molten tin and tin oxide as an inter stage reaction between oxidation of the carbon dissolving in the anode and reduction of oxygen at the solid oxide cathode .

negative: Fossil fuel phase-out Fossil fuel phase out refers to the discontinuation of the use of fossil fuels , through the decommissioning of operating fossil fuel-fired power plants , the prevention of the construction of new ones , and the use of Alternative energy to replace the role of fossil fuels .   The purpose of fossil fuel phase-out is to reduce the negative externalities that use of fossil fuels cause . Negative externalities refer to the costs a certain activity has over people who did not choose to incur in them . A direct negative externality from fossil fuels ' use is air pollution , and an indirect negative externality are mining accidents , that happen as a consequence of the extraction of fossil fuels . Fossil fuel burning contributes to climate change , as it releases greenhouse gas emissions .

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: Project Vulcan Project Vulcan is a NASA/DOE funded effort under the North American Carbon Program ( NACP ) to quantify North American fossil fuel carbon dioxide ( CO2 ) emissions at space/time scales much finer than has been achieved in the past . The initial purpose of the Vulcan Project was to aid in quantification of the North American carbon budget , to support inverse estimation of carbon sources and sinks , and to support the demands posed by higher resolution CO2 observations . The detail and scope of the Vulcan CO2 inventory has now made it a valuable tool for policymakers , demographers , social scientists and the public at large .   Project Vulcan has achieved U.S. fossil fuel CO2 emissions at < 10 km spatial scales and an hourly time scale , based on datasets such as air quality emissions reporting , census data , highway statistics , energy statistics , and econometric data . Furthermore , Vulcan includes significant process-level detail , dividing the emissions into economic sectors and sub-sectors in addition to 23 fuel types . It has been produced for the year 2002 , and an annual product spanning 1980-2006 will be available by late-2009 .   The first Vulcan inventory ( v1 .0 ) was released to the public in early April 2008 . Version 1.1 was released in February 2009 and Version 1.2 is due out in early August 2009 . In addition to the data release , establishment of the Vulcan website and a press release , a video of various aspects of atmospheric transport was released on Purdue University 's YouTube website and portions of the Vulcan inventory are available on Google Earth . As of 2015 , version 2.2 has been published on a site hosted by Arizona State University .

negative: Suess effect The Suess effect is a change in the ratio of the atmospheric concentrations of heavy isotopes of carbon ( 13C and 14C ) by the admixture of large amounts of fossil-fuel derived CO2 , which is depleted in 13CO2 and contains no 14CO2 . It is named for the Austrian chemist Hans Suess , who noted the influence of this effect on the accuracy of radiocarbon dating . More recently , the Suess effect has been used in studies of climate change . The term originally referred only to dilution of atmospheric 14CO2 . The concept was later extended to dilution of 13CO2 and to other reservoirs of carbon such as the oceans and soils .

negative: Air Pollution in Canada Air pollution in Canada arises from the increasing airborne chemicals , matter and biological materials in the air . These factors cause harm to human health , the environment and to the economy . In the Canadian context , the main contributor of air pollution stems from burning fossil fuels for power and energy . Fossil fuels continue to be the main source of fuel for Canadians , even though the government is aware of the negative effects that it has on the environment and human health . Air pollution in Canada continues to be an issue due to the pressures with climate change , increased urbanization and continued reliance on vehicles as the primary source of transportation .   A major contributor to the problem of Canadian air pollution are the Alberta Oil Sands . Though they are not closely related to major Canadian Metropolitan Areas , the quality of mostly rural Northern Alberta is poorer than areas of similar population densities in Canada . Toronto and other Canadian municipalities face environmental problems associated with air pollution due to industrial chemicals .   Air pollution is Canada continues to negatively affect the environment , leading to an increase in health problems for Canadians , especially regarding leukemia . Air pollution has increased the rate of hospital visits per year and is currently causing premature deaths .   There are current policy responses to combat the increasing rate of air pollution in Canada . The agreement is a response to Canada 's transportation and energy production infrastructure as they contribute to the problem of Air Pollution . The Canadian and United States federal governments have required each other to reduce air pollution by specific amounts annually through detailed reporting .

negative: Combustion Combustion -LSB- kəmˈbʌs.tʃən -RSB- or burning is a high-temperature exothermic redox chemical reaction between a fuel ( the reductant ) and an oxidant , usually atmospheric oxygen , that produces oxidized , often gaseous products , in a mixture termed as smoke . Combustion in a fire produces a flame , and the heat produced can make combustion self-sustaining . Combustion is often a complicated sequence of elementary radical reactions . Solid fuels , such as wood , first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce more of them . Combustion is often hot enough that light in the form of either glowing or a flame is produced . A simple example can be seen in the combustion of hydrogen and oxygen into water vapor , a reaction commonly used to fuel rocket engines . This reaction releases 242 kJ/mol of heat and reduces the enthalpy accordingly ( at constant temperature and pressure ) :   2 ( g ) + ( g ) → 2 ( g )   Combustion of an organic fuel in air is always exothermic because the double bond in O2 is much weaker than other double bonds or pairs of single bonds , and therefore the formation of the stronger bonds in the combustion products CO2 and H2O results in the release of energy . The bond energies in the fuel play only a minor role , since they are similar to those in the combustion products ; e.g. , the sum of the bond energies of CH4 is nearly the same as that of CO2 . The heat of combustion is approximately -418 kJ per mole of O2 used up in the combustion reaction , and can be estimated from the elemental composition of the fuel .   Uncatalyzed combustion in air requires fairly high temperatures . Complete combustion is stoichiometric with respect to the fuel , where there is no remaining fuel , and ideally , no remaining oxidant . Thermodynamically , the chemical equilibrium of combustion in air is overwhelmingly on the side of the products . However , complete combustion is almost impossible to achieve , since the chemical equilibrium is not necessarily reached , or may contain unburnt products such as carbon monoxide , hydrogen and even carbon ( soot or ash ) . Thus , the produced smoke is usually toxic and contains unburned or partially oxidized products . Any combustion at high temperatures in atmospheric air , which is 78 percent nitrogen , will also create small amounts of several nitrogen oxides , commonly referred to as , since the combustion of nitrogen is thermodynamically favored at high , but not low temperatures . Since combustion is rarely clean , flue gas cleaning or catalytic converters may be required by law .   Fires occur naturally , ignited by lightning strikes or by volcanic products . Combustion ( fire ) was the first controlled chemical reaction discovered by humans , in the form of campfires and bonfires , and continues to be the main method to produce energy for humanity . Usually , the fuel is carbon , hydrocarbons or more complicated mixtures such as wood that contains partially oxidized hydrocarbons . The thermal energy produced from combustion of either fossil fuels such as coal or oil , or from renewable fuels such as firewood , is harvested for diverse uses such as cooking , production of electricity or industrial or domestic heating . Combustion is also currently the only reaction used to power rockets . Combustion is also used to destroy ( incinerate ) waste , both nonhazardous and hazardous .   Oxidants for combustion have high oxidation potential and include atmospheric or pure oxygen , chlorine , fluorine , chlorine trifluoride , nitrous oxide and nitric acid . For instance , hydrogen burns in chlorine to form hydrogen chloride with the liberation of heat and light characteristic of combustion . Although usually not catalyzed , combustion can be catalyzed by platinum or vanadium , as in the contact process .

negative: Flue-gas emissions from fossil-fuel combustion Flue-gas emissions from fossil-fuel combustion refers to the combustion-product gas resulting from the burning of fossil fuels . Most fossil fuels are combusted with ambient air ( as differentiated from combustion with pure oxygen ) . Since ambient air contains about 79 volume percent gaseous nitrogen ( N2 ) , which is essentially non-combustible , the largest part of the flue gas from most fossil-fuel combustion is uncombusted nitrogen . Carbon dioxide , the next largest part of flue gas , can be as much as 10 − 25 volume percent or more of the flue gas . This is closely followed in volume by water vapor ( H2O ) created by the combustion of the hydrogen in the fuel with atmospheric oxygen . Much of the ` smoke ' seen pouring from flue gas stacks is this water vapor forming a cloud as it contacts cool air .   A typical flue gas from the combustion of fossil fuels contains very small amounts of nitrogen oxides ( NOx ) , sulfur dioxide ( SO2 ) and particulate matter . The nitrogen oxides are derived from the nitrogen in the ambient air as well as from any nitrogen-containing compounds in the fossil fuel . The sulfur dioxide is derived from any sulfur-containing compounds in the fuels . The particulate matter is composed of very small particles of solid materials and very small liquid droplets which give flue gases their smoky appearance .   The steam generators in large power plants and the process furnaces in large refineries , petrochemical and chemical plants , and incinerators burn considerable amounts of fossil fuels and therefore emit large amounts of flue gas to the ambient atmosphere . The table below presents the total amounts of flue gas typically generated by the burning of fossil fuels such as natural gas , fuel oil and coal . The data were obtained by stoichiometric  calculations .   It is of interest to note that the total amount of flue gas generated by coal combustion is only 10 percent higher than the flue gas generated by natural-gas combustion .   Note : m ³ are standard cubic meters at 0 ° C and 101.325 kPa , and scf is standard cubic feet at 60 ° F and 14.696 psia .

negative: Coal pollution mitigation Coal pollution mitigation , often referred to by the public relations term clean coal , is a series of systems and technologies that seek to mitigate the pollution and other environmental effects normally associated with the burning ( though not the mining or processing ) of coal , which is widely regarded as the dirtiest of the common fuels for industrial processes and power generation . The preferred industry term `` clean coal '' has been described as `` Orwellian '' , an oxymoron , and a myth .   Approaches attempt to mitigate emissions of carbon dioxide ( CO2 ) and other greenhouse gases , and radioactive materials , that arise from the use of coal , mainly for electrical power generation , using various technologies . Historical efforts to reduce coal pollution focused on flue-gas desulfurization starting in the 1850s and clean burn technologies . More recent developments include carbon capture and storage , which pumps and stores CO2 emissions underground , and integrated gasification combined cycle ( IGCC ) involve coal gasification , which provides a basis for increased efficiency and lower cost in capturing CO2 emissions .   There are seven technologies deployed or proposed for deployment in the United States :  carbon capture and storage ( CCS ) ,  flue-gas desulfurization ,  fluidized-bed combustion ,  integrated gasification combined cycle ( IGCC ) ,  low nitrogen oxide burners ,  selective catalytic reduction ( SCR ) , and  electrostatic precipitators .  Of the 22 demonstration projects funded by the U.S. Department of Energy since 2003 , none are in operation as of February 2017 , having been abandoned or delayed due to capital budget overruns or discontinued because of excessive operating expenses .

negative: Mesopause The mesopause is the temperature minimum at the boundary between the mesosphere and the thermosphere atmospheric regions . Due to the lack of solar heating and very strong radiative cooling from carbon dioxide , the mesosphere is the coldest region on Earth with temperatures as low as -100 ° C ( -148 ° F or 173 K ) . The altitude of the mesopause for many years was assumed to be at around 85 km ( 53 mi . ) , but observations to higher altitudes and modeling studies in the last 10 years have shown that in fact the mesopause consists of two minima - one at about 85 km and a stronger minimum at about 100 km . ( 62 mi . )   Another feature is that the summer mesopause is cooler than the winter ( sometimes referred to as the mesopause anomaly ) . It is due to a summer-to-winter circulation giving rise to upwelling at the summer pole and downwelling at the winter pole . Air rising will expand and cool resulting in a cold summer mesopause and conversely downwelling air results in compression and associated increase in temperature at the winter mesopause . In the mesosphere the summer-to-winter circulation is due to gravity wave dissipation , which deposits momentum against the mean east-west flow , resulting in a small north-south circulation .   In recent years the mesopause has also been the focus of studies on global climate change associated with increases in CO2 . Unlike the troposphere , where greenhouse gases result in the atmosphere heating up , increased CO2 in the mesosphere acts to cool the atmosphere due to increased radiative emission . This results in a measurable effect - the mesopause should become cooler with increased CO2 . Observations do show a decrease of temperature of the mesopause , though the magnitude of this decrease varies and is subject to further study . Modeling studies of this phenomenon have also been carried out .

negative: Katsuko Saruhashi was a geochemist who made some of the first measurements of carbon dioxide ( CO2 ) levels in seawater and subsequently showed the evidence in seawater and the atmosphere of the dangers of radioactive fallout .

negative: Australian Local Government Fossil Fuel Divestment In Australia , fossil fuel divestment is being led by Universities and Local Councils . In 2015 , the number of Australian councils with divestment commitments increased dramatically from 2 to 17 . On 15 September 2016 , the status of Australian council divestment was :  Fossil free investment funds held by Australian Local Councils : $ 6,181,195,620  Number of Local Councils with fossil free divestment commitments : 27   Most Australian councils can not invest in shares , meaning they have no investments directly in climate-change-contributing fossil fuel companies . However , most councils have exposure to fossil fuels via their term deposit accounts with the big Australian banks whom in turn are financing billions of dollars worth of coal and gas projects across the country . Many councils have been identifying their exposure to ` fossil ' banks and have found that the majority of Australian banks ( particularly banks other than the ` big four ' ) do not provide finance for the fossil fuel industry .   Research on which banks fund the fossil fuel industry , and those that do not , has been completed and is routinely updated by Market Forces an independent research organisation . Although there have been some public commitments indicating the Australian ` big four ' banks will not invest in certain fossil fuel related projects , at 30 June 2016 , the ` big four ' remain heavily invested in fossil fuel .

negative: FUTBOLIN FUTBOLIN ( FUll Transfer By Optimized LINe-by-line methods ) : Multi-level multiple scattering radiative transfer model for the calculation of line-by-line atmospheric emission/transmission spectra in planetary atmospheres . It has been developed by Javier Martin-Torres ( AS&M . Inc , NASA/Langley Research Center , Hampton , VA , USA ; Jet Propulsion Laboratory , Pasadena , CA ; Now at IACT ( CSIC-URG ) , Granada , SPAIN ) . It allows generating high-resolution synthetic spectra in the 0.3-1000 micrometre spectral range .   The code can handle spherical or plane-parallel atmospheres . It reads spectral lines in HITRAN or GEISA format and can handle CO2 line mixing and continuum absorption from H2O , O2 , N2 and CO2 . It also takes into account the Non Local Thermodynamic Equilibrium ( NLTE ) effects on the rotational , electronic and vibrational populations of the atmospheric species and allows to specify any combinations of clouds , coverage and spectral albedo . It has been used to model the Earth 's atmosphere , and the atmospheres of Mars , Venus , and Titan .   The code can calculate reflection , transmission , absorption , infrared cooling rate , and flux spectra .

negative: Climate change mitigation scenarios Climate change mitigation scenarios are possible futures in which global warming is reduced by deliberate actions , such as a comprehensive switch to energy sources other than fossil fuels . A typical mitigation scenario is constructed by selecting a long-range target , such as a desired atmospheric concentration of carbon dioxide ( CO2 ) , and then fitting the actions to the target , for example by placing a cap on net global and national emissions of greenhouse gases .   An increase of global temperature by more than 2 ° C has come to be the majority definition of what would constitute intolerably dangerous climate change with efforts to limit the temperature increase to 1.5 ° C above pre-industrial levels per the Paris Agreement . Some climate scientists are increasingly of the opinion that the goal should be a complete restoration of the atmosphere 's preindustrial condition , on the grounds that too protracted a deviation from those conditions will produce irreversible changes .

negative: Seaweed fuel Seaweed fuel or seaweed oil is an alternative to liquid fossil fuels that uses seaweed as its source of energy-rich oils . Like fossil fuel , seaweed fuel releases when burnt , but unlike fossil fuel , algae fuel and other biofuels only release recently removed from the atmosphere via photosynthesis as the seaweed or plant grew .   Unlike algae , seaweed does not require fresh water and can as such be grown in the sea .

negative: Tejo Power Station operations The basic operation of a thermoelectric power station is quite simple : burning fuel to release heat that transforms water from a liquid state into steam . The steam is then responsible for driving a turbine activating the machine that generates electric power .   However , the aspects involved in electric power production in the old Tejo Power Station were n't that simple because , among other things , a large and complex internal air and water system was required , as well as treating fossil fuels , which in the old power station 's case was coal .