Global warming

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Global mean land-ocean temperature change from 1880–2010, relative to the 1951–1980 mean. The black line is the annual mean and the red line is the 5-year running mean. The green bars show uncertainty estimates. Source: NASA GISS
The map shows the 10-year average (2000–2009) global mean temperature anomaly relative to the 1951–1980 mean. The largest temperature increases are in the Arctic and the Antarctic Peninsula. Source: NASA Earth Observatory[1]
Fossil fuel related CO2 emissions compared to five of IPCC's emissions scenarios. The dips are related to global recessions. Data from IPCC SRES scenarios; Data spreadsheet included with International Energy Agency's "CO2 Emissions from Fuel Combustion 2010 – Highlights"; and Supplemental IEA data. Image source: Skeptical Science

Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about 0.8 °C (1.4 °F) with about two thirds of the increase occurring over just the last three decades.[2] Warming of the climate system is unequivocal, and scientists are more than 90% certain most of it is caused by increasing concentrations of greenhouse gases produced by human activities such as deforestation and burning fossil fuels.[3][4][5][6] These findings are recognized by the national science academies of all the major industrialized countries.[7][A]

Climate model projections are summarized in the 2007 Fourth Assessment Report (AR4) by the Intergovernmental Panel on Climate Change (IPCC). They indicate that during the 21st century the global surface temperature is likely to rise a further 1.1 to 2.9 °C (2 to 5.2 °F) for their lowest emissions scenario and 2.4 to 6.4 °C (4.3 to 11.5 °F) for their highest.[8] The ranges of these estimates arise from the use of models with differing sensitivity to greenhouse gas concentrations.[9][10]

An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, and a probable expansion of subtropical deserts.[11] Warming is expected to be strongest in the Arctic and would be associated with continuing retreat of glaciers, permafrost and sea ice. Other likely effects of the warming include more frequent occurrence of extreme weather events including heatwaves, droughts and heavy rainfall events, species extinctions due to shifting temperature regimes, and changes in crop yields. Warming and related changes will vary from region to region around the globe, with projections being more robust in some areas than others.[12] In a 4 °C world, the limits for human adaptation are likely to be exceeded in many parts of the world, while the limits for adaptation for natural systems would largely be exceeded throughout the world. Hence, the ecosystem services upon which human livelihoods depend would not be preserved.[13]

Most countries are parties to the United Nations Framework Convention on Climate Change (UNFCCC),[14] whose ultimate objective is to prevent "dangerous" anthropogenic (i.e., human-induced) climate change.[15] Parties to the UNFCCC have adopted a range of policies designed to reduce greenhouse gas emissions[16]:10[17][18][19]:9 and to assist in adaptation to global warming.[16]:13[19]:10[20][21] Parties to the UNFCCC have agreed that deep cuts in emissions are required,[22] and that future global warming should be limited to below 2.0 °C (3.6 °F) relative to the pre-industrial level.[22][B] Analyses by the United Nations Environment Programme (published in 2011)[23] and International Energy Agency (2011)[24] suggest that current efforts to reduce emissions may be inadequately stringent to meet the UNFCCC's 2 °C target.

Contents

Observed temperature changes

Main article: Instrumental temperature record

Evidence for warming of the climate system includes observed increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.[25][26][27] The Earth's average surface temperature, expressed as a linear trend, rose by 0.74±0.18 °C over the period 1906–2005. The rate of warming over the last half of that period was almost double that for the period as a whole (0.13±0.03 °C per decade, versus 0.07±0.02 °C per decade). The urban heat island effect is very small, estimated to account for less than 0.002 °C of warming per decade since 1900.[28] Temperatures in the lower troposphere have increased between 0.13 and 0.22 °C (0.22 and 0.4 °F) per decade since 1979, according to satellite temperature measurements. Climate proxies show the temperature to have been relatively stable over the one or two thousand years before 1850, with regionally varying fluctuations such as the Medieval Warm Period and the Little Ice Age.[29]

Recent estimates by NASA's Goddard Institute for Space Studies (GISS) and the National Climatic Data Center show that 2005 and 2010 tied for the planet's warmest year since reliable, widespread instrumental measurements became available in the late 19th century, exceeding 1998 by a few hundredths of a degree.[30][31][32] Current estimates by the Climatic Research Unit (CRU) show 2005 as the second warmest year, behind 1998 with 2003 and 2010 tied for third warmest year, however, “the error estimate for individual years ... is at least ten times larger than the differences between these three years.”[33] The World Meteorological Organization (WMO) statement on the status of the global climate in 2010 explains that, “The 2010 nominal value of +0.53 °C ranks just ahead of those of 2005 (+0.52 °C) and 1998 (+0.51 °C), although the differences between the three years are not statistically significant...”[34]

Temperatures in 1998 were unusually warm because the strongest El Niño in the past century occurred during that year.[35] Global temperature is subject to short-term fluctuations that overlay long term trends and can temporarily mask them. The relative stability in temperature from 2002 to 2009 is consistent with such an episode.[36][37]

Temperature changes vary over the globe. Since 1979, land temperatures have increased about twice as fast as ocean temperatures (0.25 °C per decade against 0.13 °C per decade).[38] Ocean temperatures increase more slowly than land temperatures because of the larger effective heat capacity of the oceans and because the ocean loses more heat by evaporation.[39] The Northern Hemisphere warms faster than the Southern Hemisphere because it has more land and because it has extensive areas of seasonal snow and sea-ice cover subject to ice-albedo feedback. Although more greenhouse gases are emitted in the Northern than Southern Hemisphere this does not contribute to the difference in warming because the major greenhouse gases persist long enough to mix between hemispheres.[40]

The thermal inertia of the oceans and slow responses of other indirect effects mean that climate can take centuries or longer to adjust to changes in forcing. Climate commitment studies indicate that even if greenhouse gases were stabilized at 2000 levels, a further warming of about 0.5 °C (0.9 °F) would still occur.[41]

Initial causes of temperature changes (external forcings)

Greenhouse effect schematic showing energy flows between space, the atmosphere, and earth's surface. Energy exchanges are expressed in watts per square meter (W/m2).
This graph, known as the "Keeling Curve", shows the long-term increase of atmospheric carbon dioxide (CO2) concentrations from 1958–2008. Monthly CO2 measurements display seasonal oscillations in an upward trend; each year's maximum occurs during the Northern Hemisphere's late spring, and declines during its growing season as plants remove some atmospheric CO2.

External forcing refers to processes external to the climate system (though not necessarily external to Earth) that influence climate. Climate responds to several types of external forcing, such as radiative forcing due to changes in atmospheric composition (mainly greenhouse gas concentrations), changes in solar luminosity, volcanic eruptions, and variations in Earth's orbit around the Sun.*[42]:0 Attribution of recent climate change focuses on the first three types of forcing. Orbital cycles vary slowly over tens of thousands of years and at present are in an overall cooling trend which would be expected to lead towards an ice age, but the 20th century instrumental temperature record shows a sudden rise in global temperatures.[43]

Greenhouse gases

Main articles: Greenhouse gas, Greenhouse effect, Radiative forcing, and Carbon dioxide in Earth's atmosphere

The greenhouse effect is the process by which absorption and emission of infrared radiation by gases in the atmosphere warm a planet's lower atmosphere and surface. It was proposed by Joseph Fourier in 1824 and was first investigated quantitatively by Svante Arrhenius in 1896.[44]

Naturally occurring amounts of greenhouse gases have a mean warming effect of about 33 °C (59 °F).[45][C] The major greenhouse gases are water vapor, which causes about 36–70% of the greenhouse effect; carbon dioxide (CO2), which causes 9–26%; methane (CH4), which causes 4–9%; and ozone (O3), which causes 3–7%.[46][47][48] Clouds also affect the radiation balance through cloud forcings similar to greenhouse gases.

Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs and nitrous oxide. The concentrations of CO2 and methane have increased by 36% and 148% respectively since 1750.[49] These levels are much higher than at any time during the last 800,000 years, the period for which reliable data has been extracted from ice cores.[50][51][52][53] Less direct geological evidence indicates that CO2 values higher than this were last seen about 20 million years ago.[54] Fossil fuel burning has produced about three-quarters of the increase in CO2 from human activity over the past 20 years. The rest of this increase is caused mostly by changes in land-use, particularly deforestation.[55]

Per capita greenhouse gas emissions in 2005, including land-use change.
Total greenhouse gas emissions in 2005, including land-use change.

Over the last three decades of the 20th century, gross domestic product per capita and population growth were the main drivers of increases in greenhouse gas emissions.[56] CO2 emissions are continuing to rise due to the burning of fossil fuels and land-use change.[57][58]:71 Emissions can be attributed to different regions. The two figures opposite show annual greenhouse gas emissions for the year 2005, including land-use change. Attribution of emissions due to land-use change is a controversial issue.[59][60]:289

Emissions scenarios, estimates of changes in future emission levels of greenhouse gases, have been projected that depend upon uncertain economic, sociological, technological, and natural developments.[61] In most scenarios, emissions continue to rise over the century, while in a few, emissions are reduced.[62][63] Fossil fuel reserves are abundant, and will not limit carbon emissions in the 21st century.[64] Emission scenarios, combined with modelling of the carbon cycle, have been used to produce estimates of how atmospheric concentrations of greenhouse gases might change in the future. Using the six IPCC SRES "marker" scenarios, models suggest that by the year 2100, the atmospheric concentration of CO2 could range between 541 and 970 ppm.[65] This is an increase of 90–250% above the concentration in the year 1750.

The popular media and the public often confuse global warming with ozone depletion, i.e., the destruction of stratospheric ozone by chlorofluorocarbons.[66][67] Although there are a few areas of linkage, the relationship between the two is not strong. Reduced stratospheric ozone has had a slight cooling influence on surface temperatures, while increased tropospheric ozone has had a somewhat larger warming effect.[68]

Particulates and soot

Global dimming, a gradual reduction in the amount of global direct irradiance at the Earth's surface, has partially counteracted global warming from 1960 to the present.[69] The main cause of this dimming is particulates produced by volcanoes and human made pollutants, which exerts a cooling effect by increasing the reflection of incoming sunlight. The effects of the products of fossil fuel combustion—CO2 and aerosols—have largely offset one another in recent decades, so that net warming has been due to the increase in non-CO2 greenhouse gases such as methane.[70] Radiative forcing due to particulates is temporally limited due to wet deposition which causes them to have an atmospheric lifetime of one week. Carbon dioxide has a lifetime of a century or more, and as such, changes in particulate concentrations will only delay climate changes due to carbon dioxide.[71]

In addition to their direct effect by scattering and absorbing solar radiation, particulates have indirect effects on the radiation budget.[72] Sulfates act as cloud condensation nuclei and thus lead to clouds that have more and smaller cloud droplets. These clouds reflect solar radiation more efficiently than clouds with fewer and larger droplets, known as the Twomey effect.[73] This effect also causes droplets to be of more uniform size, which reduces growth of raindrops and makes the cloud more reflective to incoming sunlight, known as the Albrecht effect.[74] Indirect effects are most noticeable in marine stratiform clouds, and have very little radiative effect on convective clouds. Indirect effects of particulates represent the largest uncertainty in radiative forcing.[75]

Soot may cool or warm the surface, depending on whether it is airborne or deposited. Atmospheric soot directly absorb solar radiation, which heats the atmosphere and cools the surface. In isolated areas with high soot production, such as rural India, as much as 50% of surface warming due to greenhouse gases may be masked by atmospheric brown clouds.[76] When deposited, especially on glaciers or on ice in arctic regions, the lower surface albedo can also directly heat the surface.[77] The influences of particulates, including black carbon, are most pronounced in the tropics and sub-tropics, particularly in Asia, while the effects of greenhouse gases are dominant in the extratropics and southern hemisphere.[78]

Solar variation

Main article: Solar variation

Variations in solar output have been the cause of past climate changes.[79] The effect of changes in solar forcing in recent decades is uncertain, but small, with some studies showing a slight cooling effect,[80] while others studies suggest a slight warming effect.*[42][81][82][83]

Greenhouse gases and solar forcing affect temperatures in different ways. While both increased solar activity and increased greenhouse gases are expected to warm the troposphere, an increase in solar activity should warm the stratosphere while an increase in greenhouse gases should cool the stratosphere.*[42] Radiosonde (weather balloon) data show the stratosphere has cooled over the period since observations began (1958), though there is greater uncertainty in the early radiosonde record. Satellite observations, which have been available since 1979, also show cooling.[84]

A related hypothesis, proposed by Henrik Svensmark, is that magnetic activity of the sun deflects cosmic rays that may influence the generation of cloud condensation nuclei and thereby affect the climate.[85] Other research has found no relation between warming in recent decades and cosmic rays.[86][87] The influence of cosmic rays on cloud cover is about a factor of 100 lower than needed to explain the observed changes in clouds or to be a significant contributor to present-day climate change.[88]

Studies in 2011 have indicated that solar activity may be slowing, and that the next solar cycle could be delayed. To what extent is not yet clear; Solar Cycle 25 is due to start in 2020, but may be delayed to 2022 or even longer. It is even possible that Sol could be heading towards another Maunder Minimum. While there is not yet a definitive link between solar sunspot activity and global temperatures, the scientists conducting the solar activity study believe that global greenhouse gas emissions would prevent any possible cold snap.[89]

Feedback

Main article: Climate change feedback

Feedback is a process in which changing one quantity changes a second quantity, and the change in the second quantity in turn changes the first. Positive feedback increases the change in the first quantity while negative feedback reduces it. Feedback is important in the study of global warming because it may amplify or diminish the effect of a particular process.

The main positive feedback in the climate system is the water vapor feedback. The main negative feedback is radiative cooling through the Stefan–Boltzmann law, which increases as the fourth power of temperature. Positive and negative feedbacks are not imposed as assumptions in the models, but are instead emergent properties that result from the interactions of basic dynamical and thermodynamic processes.

A wide range of potential feedback processes exist, such as Arctic methane release and ice-albedo feedback. Consequentially, potential tipping points may exist, which may have the potential to cause abrupt climate change.[90]

For example, the "emission scenarios" used by IPCC in its 2007 report primarily examined greenhouse gas emissions from human sources. In 2011, a joint study by the US National Snow and Ice Data Center and National Oceanic and Atmospheric Administration calculated the additional greenhouse gas emissions that would emanate from melted and decomposing permafrost, even if policymakers attempt to reduce human emissions from the currently-unfolding A1FI scenario to the A1B scenario.[91] The team found that even at the much lower level of human emissions, permafrost thawing and decomposition would still result in 190 Gt C of permafrost carbon being added to the atmosphere on top of the human sources. Importantly, the team made three extremely conservative assumptions: (1) that policymakers will embrace the A1B scenario instead of the currently-unfolding A1FI scenario, (2) that all of the carbon would be released as carbon dioxide instead of methane, which is more likely and over a 20 year lifetime has 72x the greenhouse warming power of CO2, and (3) their model did not project additional temperature rise caused by the release of these additional gases.[91][92] These very conservative permafrost carbon dioxide emissions are equivalent to about 1/2 of all carbon released from fossil fuel burning since the dawn of the Industrial Age,[93] and is enough to raise atmospheric concentrations by an additional 87±29 ppm, beyond human emissions. Once initiated, permafrost carbon forcing (PCF) is irreversible, is strong compared to other global sources and sinks of atmospheric CO2, and due to thermal inertia will continue for many years even if atmospheric warming stops.[91] A great deal of this permafrost carbon is actually being released as highly flammable methane instead of carbon dioxide.[94] IPCC 2007's temperature projections did not take any of the permafrost carbon emissions into account and therefore underestimate the degree of expected climate change.[91][92]

Other research published in 2011 found that increased emissions of methane could instigate significant feedbacks that amplify the warming attributable to the methane alone. The researchers found that a 2.5-fold increase in methane emissions would cause indirect effects that increase the warming 250% above that of the methane alone. For a 5.2-fold increase, the indirect effects would be 400% of the warming from the methane alone.[95]

Climate models

Main article: Global climate model
Calculations of global warming prepared in or before 2001 from a range of climate models under the SRES A2 emissions scenario, which assumes no action is taken to reduce emissions and regionally divided economic development.
The geographic distribution of surface warming during the 21st century calculated by the HadCM3 climate model if a business as usual scenario is assumed for economic growth and greenhouse gas emissions. In this figure, the globally averaged warming corresponds to 3.0 °C (5.4 °F).

A climate model is a computerized representation of the five components of the climate system: Atmosphere, hydrosphere, cryosphere, land surface, and biosphere.[96] Such models are based on physical principles including fluid dynamics, thermodynamics and radiative transfer. There can be components which represent air movement, temperature, clouds, and other atmospheric properties; ocean temperature, salt content, and circulation; ice cover on land and sea; the transfer of heat and moisture from soil and vegetation to the atmosphere; chemical and biological processes; and others.[97]

Although researchers attempt to include as many processes as possible, simplifications of the actual climate system are inevitable because of the constraints of available computer power and limitations in knowledge of the climate system. Results from models can also vary due to different greenhouse gas inputs and the model's climate sensitivity. For example, the uncertainty in IPCC's 2007 projections is caused by (1) the use of multiple models with differing sensitivity to greenhouse gas concentrations, (2) the use of differing estimates of humanities' future greenhouse gas emissions, (3) any additional emissions from climate feedbacks that were not included in the models IPCC used to prepare its report, i.e., greenhouse gas releases from permafrost.[91]

The models do not assume the climate will warm due to increasing levels of greenhouse gases. Instead the models predict how greenhouse gases will interact with radiative transfer and other physical processes. One of the mathematical results of these complex equations is a prediction whether warming or cooling will occur.[98]

Recent research has called special attention to the need to refine models with respect to the effect of clouds[99] and the carbon cycle.[100][101][102]

Models are also used to help investigate the causes of recent climate change by comparing the observed changes to those that the models project from various natural and human-derived causes. Although these models do not unambiguously attribute the warming that occurred from approximately 1910 to 1945 to either natural variation or human effects, they do indicate that the warming since 1970 is dominated by man-made greenhouse gas emissions.*[42]

The physical realism of models is tested by examining their ability to simulate current or past climates.[103]

Current climate models produce a good match to observations of global temperature changes over the last century, but do not simulate all aspects of climate.[104] Not all effects of global warming are accurately predicted by the climate models used by the IPCC. Observed Arctic shrinkage has been faster than that predicted.[105] Precipitation increased proportional to atmospheric humidity, and hence significantly faster than current global climate models predict.[106][107]

Expected effects

Main articles: Effects of global warming and Regional effects of global warming

"Detection" is the process of demonstrating that climate has changed in some defined statistical sense, without providing a reason for that change. Detection does not imply attribution of the detected change to a particular cause. "Attribution" of causes of climate change is the process of establishing the most likely causes for the detected change with some defined level of confidence.[108] Detection and attribution may also be applied to observed changes in physical, ecological and social systems.[109]

Natural systems

Global warming has been detected in a number of systems. Some of these changes, e.g., based on the instrumental temperature record, have been described in the section on temperature changes. Rising sea levels and observed decreases in snow and ice extent are consistent with warming.[110] Most of the increase in global average temperature since the mid-20th century is, with high probability,[D] attributable to human-induced changes in greenhouse gas concentrations.[111]

Even with current policies to reduce emissions, global emissions are still expected to continue to grow over the coming decades.[112] Over the course of the 21st century, increases in emissions at or above their current rate would very likely induce changes in the climate system larger than those observed in the 20th century.

In the IPCC Fourth Assessment Report, across a range of future emission scenarios, model-based estimates of sea level rise for the end of the 21st century (the year 2090–2099, relative to 1980–1999) range from 0.18 to 0.59 m. These estimates, however, were not given a likelihood due to a lack of scientific understanding, nor was an upper bound given for sea level rise. On the timescale of centuries to millennia, the melting of ice sheets could result in even higher sea level rise. Partial deglaciation of the Greenland ice sheet, and possibly the West Antarctic Ice Sheet, could contribute 4–6 metres (13 to 20 ft) or more to sea level rise.[113]

Changes in regional climate are expected to include greater warming over land, with most warming at high northern latitudes, and least warming over the Southern Ocean and parts of the North Atlantic Ocean.[112] Snow cover area and sea ice extent are expected to decrease, with the Arctic expected to be largely ice-free in September by 2037.[114] The frequency of hot extremes, heat waves, and heavy precipitation will very likely increase.

Ecological systems

In terrestrial ecosystems, the earlier timing of spring events, and poleward and upward shifts in plant and animal ranges, have been linked with high confidence to recent warming.[110] Future climate change is expected to particularly affect certain ecosystems, including tundra, mangroves, and coral reefs.[112] It is expected that most ecosystems will be affected by higher atmospheric CO2 levels, combined with higher global temperatures.[115] Overall, it is expected that climate change will result in the extinction of many species and reduced diversity of ecosystems.[116]

Social systems

Vulnerability of human societies to climate change mainly lies in the effects of extreme weather events rather than gradual climate change.[117] Impacts of climate change so far include adverse effects on small islands,[118] adverse effects on indigenous populations in high-latitude areas,[119] and small but discernable effects on human health.[120] Over the 21st century, climate change is likely to adversely affect hundreds of millions of people through increased coastal flooding, reductions in water supplies, increased malnutrition and increased health impacts.[121]

Future warming of around 3 °C (by 2100, relative to 1990–2000) could result in increased crop yields in mid- and high-latitude areas, but in low-latitude areas, yields could decline, increasing the risk of malnutrition.[118] A similar regional pattern of net benefits and costs could occur for economic (market-sector) effects.[120] Warming above 3 °C could result in crop yields falling in temperate regions, leading to a reduction in global food production.[122] Most economic studies suggest losses of world gross domestic product (GDP) for this magnitude of warming.[123][124]

Responses to global warming

Mitigation

Main article: Climate change mitigation
See also: Fee and dividend

Reducing the amount of future climate change is called mitigation of climate change. The IPCC defines mitigation as activities that reduce greenhouse gas (GHG) emissions, or enhance the capacity of carbon sinks to absorb GHGs from the atmosphere.[125] Many countries, both developing and developed, are aiming to use cleaner, less polluting, technologies.[58]:192 Use of these technologies aids mitigation and could result in substantial reductions in CO2 emissions. Policies include targets for emissions reductions, increased use of renewable energy, and increased energy efficiency. Studies indicate substantial potential for future reductions in emissions.[126]

To limit warming to the lower range in the overall IPCC's "Summary Report for Policymakers"[127] means adopting policies that will limit emissions to one of the significantly different scenarios described in the full report.[128] This will become more and more difficult, since each year of high emissions will require even more drastic measures in later years to stabilize at a desired atmospheric concentration of greenhouse gases, and energy-related carbon-dioxide (CO2) emissions in 2010 were the highest in history, breaking the prior record set in 2008.[129]

Since even in the most optimistic scenario, fossil fuels are going to be used for years to come, mitigation may also involve carbon capture and storage, a process that traps CO2 produced by factories and gas or coal power stations and then stores it, usually underground.[130]

Adaptation

Main article: Adaptation to global warming

Other policy responses include adaptation to climate change. Adaptation to climate change may be planned, e.g., by local or national government, or spontaneous, i.e., done privately without government intervention.[131] The ability to adapt is closely linked to social and economic development.[126] Even societies with high capacities to adapt are still vulnerable to climate change. Planned adaptation is already occurring on a limited basis. The barriers, limits, and costs of future adaptation are not fully understood.

Geoengineering

A body of the scientific literature has developed which considers alternative geoengineering techniques for climate change mitigation.[132] In the IPCC's Fourth Assessment Report (published in 2007) Working Group III (WG3) assessed some "apparently promising" geoengineering techniques, including ocean fertilization, capturing and sequestering CO2, and techniques for reducing the amount of sunlight absorbed by the Earth's atmospheric system.[132] The IPCC's overall conclusion was that geoengineering options remained "largely speculative and unproven, (...) with the risk of unknown side-effects."[133] In the IPCC's[133] judgement, reliable cost estimates for geoengineering options had not yet been published.

As most geoengineering techniques would affect the entire globe, deployment would likely require global public acceptance and an adequate global legal and regulatory framework, as well as significant further scientific research.[134]

Views on global warming

Main articles: Global warming controversy and Politics of global warming
See also: Scientific opinion on climate change and Public opinion on climate change

There are different views over what the appropriate policy response to climate change should be.[135] These competing views weigh the benefits of limiting emissions of greenhouse gases against the costs. In general, it seems likely that climate change will impose greater damages and risks in poorer regions.[136]

Global warming controversy

The global warming controversy refers to a variety of disputes, significantly more pronounced in the popular media than in the scientific literature,[137][138] regarding the nature, causes, and consequences of global warming. The disputed issues include the causes of increased global average air temperature, especially since the mid-20th century, whether this warming trend is unprecedented or within normal climatic variations, whether humankind has contributed significantly to it, and whether the increase is wholly or partially an artifact of poor measurements. Additional disputes concern estimates of climate sensitivity, predictions of additional warming, and what the consequences of global warming will be.

In the scientific literature, there is a strong consensus that global surface temperatures have increased in recent decades and that the trend is caused mainly by human-induced emissions of greenhouse gases. No scientific body of national or international standing disagrees with this view,[139][140] though a few organisations hold non-committal positions.

From 1990-1997 in the United States, conservative think tanks mobilized to undermine the legitimacy of global warming as a social problem. They challenged the scientific evidence; argued that global warming will have benefits; and asserted that proposed solutions would do more harm than good.[141]

Politics

Most countries are Parties to the United Nations Framework Convention on Climate Change (UNFCCC).[144] The ultimate objective of the Convention is to prevent "dangerous" human interference of the climate system.[145] As is stated in the Convention, this requires that GHG concentrations are stabilized in the atmosphere at a level where ecosystems can adapt naturally to climate change, food production is not threatened, and economic development can proceed in a sustainable fashion.[146] The Framework Convention was agreed in 1992, but since then, global emissions have risen.[147] During negotiations, the G77 (a lobbying group in the United Nations representing 133 developing nations)[148]:4 pushed for a mandate requiring developed countries to "[take] the lead" in reducing their emissions.[149] This was justified on the basis that: the developed world's emissions had contributed most to the stock of GHGs in the atmosphere; per-capita emissions (i.e., emissions per head of population) were still relatively low in developing countries; and the emissions of developing countries would grow to meet their development needs.[60]:290 This mandate was sustained in the Kyoto Protocol to the Framework Convention,[60]:290 which entered into legal effect in 2005.[150]

In ratifying the Kyoto Protocol, most developed countries accepted legally binding commitments to limit their emissions. These first-round commitments expire in 2012.[150] US President George W. Bush rejected the treaty on the basis that "it exempts 80% of the world, including major population centers such as China and India, from compliance, and would cause serious harm to the US economy."[148]:5

At the 15th UNFCCC Conference of the Parties, held in 2009 at Copenhagen, several UNFCCC Parties produced the Copenhagen Accord.[151] Parties associated with the Accord (140 countries, as of November 2010)[152]:9 aim to limit the future increase in global mean temperature to below 2 °C.[153] A preliminary assessment published in November 2010 by the United Nations Environment Programme (UNEP) suggests a possible "emissions gap" between the voluntary pledges made in the Accord and the emissions cuts necessary to have a "likely" (greater than 66% probability) chance of meeting the 2 °C objective.[152]:10–14 The UNEP assessment takes the 2 °C objective as being measured against the pre-industrial global mean temperature level. To having a likely chance of meeting the 2 °C objective, assessed studies generally indicated the need for global emissions to peak before 2020, with substantial declines in emissions thereafter.

The 16th Conference of the Parties (COP16) was held at Cancún in 2010. It produced an agreement, not a binding treaty, that the Parties should take urgent action to reduce greenhouse gas emissions to meet a goal of limiting global warming to 2 °C above pre-industrial temperatures. It also recognized the need to consider strengthening the goal to a global average rise of 1.5 °C.[154]

Public opinion

In 2007–2008 Gallup Polls surveyed 127 countries. Over a third of the world's population was unaware of global warming, with people in developing countries less aware than those in developed, and those in Africa the least aware. Of those aware, Latin America leads in belief that temperature changes are a result of human activities while Africa, parts of Asia and the Middle East, and a few countries from the Former Soviet Union lead in the opposite belief.[156] In the Western world, opinions over the concept and the appropriate responses are divided. Nick Pidgeon of Cardiff University said that "results show the different stages of engagement about global warming on each side of the Atlantic", adding, "The debate in Europe is about what action needs to be taken, while many in the U.S. still debate whether climate change is happening."[157][158] A 2010 poll by the Office of National Statistics found that 75% of UK respondents were at least "fairly convinced" that the world's climate is changing, compared to 87% in a similar survey in 2006.[159] A January 2011 ICM poll in the UK found 83% of respondents viewed climate change as a current or imminent threat, while 14% said it was no threat. Opinion was unchanged from an August 2009 poll asking the same question, though there had been a slight polarisation of opposing views.[160]

A survey in October, 2009 by the Pew Research Center for the People & the Press showed decreasing public perception in the United States that global warming was a serious problem. All political persuasions showed reduced concern with lowest concern among Republicans, only 35% of whom considered there to be solid evidence of global warming.[161] The cause of this marked difference in public opinion between the United States and the global public is uncertain but the hypothesis has been advanced that clearer communication by scientists both directly and through the media would be helpful in adequately informing the American public of the scientific consensus and the basis for it.[162] The U.S. public appears to be unaware of the extent of scientific consensus regarding the issue, with 59% believing that scientists disagree "significantly" on global warming.[163]

By 2010, with 111 countries surveyed, Gallup determined that there was a substantial decrease in the number of Americans and Europeans who viewed Global Warming as a serious threat. In the United States, a little over half the population (53%) now viewed it as a serious concern for either themselves or their families; a number 10 percentage points below the 2008 poll (63%). Latin America had the biggest rise in concern, with 73% saying global warming was a serious threat to their families.[164] That global poll also found that people are more likely to attribute global warming to human activities than to natural causes, except in the USA where nearly half (47%) of the population attributed global warming to natural causes.[165]

On the other hand, in May 2011 a joint poll by Yale and George Mason Universities found that nearly half the people in the USA (47%) attribute global warming to human activities, compared to 36% blaming it on natural causes. Only 5% of the 35% who were "disengaged", "doubtful", or "dismissive" of global warming were aware that 97% of publishing US climate scientists agree global warming is happening and is primarily caused by humans.[166]

Researchers at the University of Michigan have found that the public's belief as to the causes of global warming depends on the wording choice used in the polls.[167]

In the United States, according to the Public Policy Institute of California's (PPIC) eleventh annual survey on environmental policy issues, 75% said they believe global warming is a very serious or somewhat serious threat to the economy and quality of life in California.[168]

A July 2011 Rasmussen Reports poll found that 69% of adults in the USA believe it is at least somewhat likely that some scientists have falsified global warming research.[155]

A September 2011 Angus Reid Public Opinion poll found that Britons (43%) are less likely than Americans (49%) or Canadians (52%) to say that "global warming is a fact and is mostly caused by emissions from vehicles and industrial facilities." The same poll found that 20% of Americans, 20% of Britons and 14% of Canadians think "global warming is a theory that has not yet been proven."[169]

Other views

Most scientists agree that humans are contributing to observed climate change.[57][170] National science academies have called on world leaders for policies to cut global emissions.[171] However, some scientists and non-scientists question aspects of climate-change science.[170][172][173]

Organizations such as the libertarian Competitive Enterprise Institute, conservative commentators, and some companies such as ExxonMobil have challenged IPCC climate change scenarios, funded scientists who disagree with the scientific consensus, and provided their own projections of the economic cost of stricter controls.[174][175][176][177] In the finance industry, Deutsche Bank has set up an institutional climate change investment division (DBCCA),[178] which has commissioned and published research[179] on the issues and debate surrounding global warming.[180] Environmental organizations and public figures have emphasized changes in the current climate and the risks they entail, while promoting adaptation to changes in infrastructural needs and emissions reductions.[181] Some fossil fuel companies have scaled back their efforts in recent years,[182] or called for policies to reduce global warming.[183]

Etymology

The term global warming was probably first used in its modern sense on 8 August 1975 in a science paper by Wally Broecker in the journal Science called "Are we on the brink of a pronounced global warming?".[184][185][186] Broecker's choice of words was new and represented a significant recognition that the climate was warming; previously the phrasing used by scientists was "inadvertent climate modification," because while it was recognized humans could change the climate, no one was sure which direction it was going.[187] The National Academy of Sciences first used global warming in a 1979 paper called the Charney Report, it said: "if carbon dioxide continues to increase, [we find] no reason to doubt that climate changes will result and no reason to believe that these changes will be negligible."[188] The report made a distinction between referring to surface temperature changes as global warming, while referring to other changes caused by increased CO2 as climate change.[187]

Global warming became more widely popular after 1988 when NASA climate scientist James Hansen used the term in a testimony to Congress.[187] He said: "global warming has reached a level such that we can ascribe with a high degree of confidence a cause and effect relationship between the greenhouse effect and the observed warming."[189] His testimony was widely reported and afterward global warming was commonly used by the press and in public discourse.[187]

See also

Book: Global warming
Wikipedia books are collections of articles that can be downloaded or ordered in print.


Notes

  1. ^ The 2001 joint statement was signed by the national academies of science of Australia, Belgium, Brazil, Canada, the Caribbean, the People's Republic of China, France, Germany, India, Indonesia, Ireland, Italy, Malaysia, New Zealand, Sweden, and the UK.[190] The 2005 statement added Japan, Russia, and the U.S. The 2007 statement added Mexico and South Africa. The Network of African Science Academies, and the Polish Academy of Sciences have issued separate statements. Professional scientific societies include American Astronomical Society, American Chemical Society, American Geophysical Union, American Institute of Physics, American Meteorological Society, American Physical Society, American Quaternary Association, Australian Meteorological and Oceanographic Society, Canadian Foundation for Climate and Atmospheric Sciences, Canadian Meteorological and Oceanographic Society, European Academy of Sciences and Arts, European Geosciences Union, European Science Foundation, Geological Society of America, Geological Society of Australia, Geological Society of London-Stratigraphy Commission, InterAcademy Council, International Union of Geodesy and Geophysics, International Union for Quaternary Research, National Association of Geoscience Teachers, National Research Council (US), Royal Meteorological Society, and World Meteorological Organization.
  2. ^ Earth has already experienced almost 1/2 of the 2.0 °C (3.6 °F) described in the Cancun Agreement. In the last 100 years, Earth's average surface temperature increased by about 0.8 °C (1.4 °F) with about two thirds of the increase occurring over just the last three decades.[2]
  3. ^ Note that the greenhouse effect produces an average worldwide temperature increase of about 33 °C (59 °F) compared to black body predictions without the greenhouse effect, not an average surface temperature of 33 °C (91 °F). The average worldwide surface temperature is about 14 °C (57 °F).[45]
  4. ^ In the IPCC Fourth Assessment Report, published in 2007, this attribution is given a probability of greater than 90%, based on expert judgement.[191] According to the US National Research Council Report – Understanding and Responding to Climate Change – published in 2008, "[most] scientists agree that the warming in recent decades has been caused primarily by human activities that have increased the amount of greenhouse gases in the atmosphere."[57]

Citations

  1. ^ 2009 Ends Warmest Decade on Record. NASA Earth Observatory Image of the Day, 22 January 2010.
  2. ^ a b [Notes-FullReport] America's Climate Choices. Washington, D.C.: The National Academies Press. 2011. p. 15. ISBN 978-0-309-14585-5. http://www.nap.edu/openbook.php?record_id=12781&page=1. "The average temperature of the Earth’s surface increased by about 1.4 °F (0.8 °C) over the past 100 years, with about 1.0 °F (0.6 °C) of this warming occurring over just the past three decades" 
  3. ^ "Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level." IPCC, Synthesis Report, Section 1.1: Observations of climate change, in IPCC AR4 SYR 2007.
  4. ^ "Three different approaches are used to describe uncertainties each with a distinct form of language. * * * Where uncertainty in specific outcomes is assessed using expert judgment and statistical analysis of a body of evidence (e.g. observations or model results), then the following likelihood ranges are used to express the assessed probability of occurrence: virtually certain >99%; extremely likely >95%; very likely >90%......" IPCC, Synthesis Report, Treatment of Uncertainty, in IPCC AR4 SYR 2007.
  5. ^ IPCC, Synthesis Report, Section 2.4: Attribution of climate change, in IPCC AR4 SYR 2007.
  6. ^ [Notes-SciPanel] America's Climate Choices: Panel on Advancing the Science of Climate Change; National Research Council (2010). Advancing the Science of Climate Change. Washington, D.C.: The National Academies Press. ISBN 0309145880. http://www.nap.edu/catalog.php?record_id=12782. "(p1) ... there is a strong, credible body of evidence, based on multiple lines of research, documenting that climate is changing and that these changes are in large part caused by human activities. While much remains to be learned, the core phenomenon, scientific questions, and hypotheses have been examined thoroughly and have stood firm in the face of serious scientific debate and careful evaluation of alternative explanations. * * * (p21-22) Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities." 
  7. ^ [Notes-SciAcademy Statement] "Joint Science Academies' Statement" (PDF). http://nationalacademies.org/onpi/06072005.pdf. Retrieved 2010-08-09. 
  8. ^ Meehl et al., Chap. 10: Global Climate Projections, Sec. 10.ES: Mean Temperature, in IPCC AR4 WG1 2007.
  9. ^ Schneider Von Deimling, Thomas; Held, Ganopolski, Rahmstorf (2006). "Climate sensitivity estimated from ensemble simulations of glacial climate". Climate Dynamics. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.172.3264&rep=rep1&type=pdf. Retrieved 20 July 2011. 
  10. ^ Meehl et al., Chap. 10: Global Climate Projections, Section 10.5: Quantifying the Range of Climate Change, in IPCC AR4 WG1 2007.
  11. ^ [Notes-Lu-2007] Lu, Jian; Vecchi, Gabriel A.; Reichler, Thomas (2007). "Expansion of the Hadley cell under global warming" (PDF). Geophysical Research Letters 34 (6): L06805. Bibcode 2007GeoRL..3406805L. doi:10.1029/2006GL028443. http://www.atmos.berkeley.edu/~jchiang/Class/Spr07/Geog257/Week10/Lu_Hadley06.pdf. 
  12. ^ Solomon et al., Technical Summary, Section TS.5.3: Regional-Scale Projections, in IPCC AR4 WG1 2007.
  13. ^ Warren, Rachel (Jan 2011). "The role of interactions in a world implementing change adaptation and mitigation solutions to climate". Phil. Trans. R. Soc. A 369 (1934): 217–241. Bibcode 2011RSPTA.369..217W. doi:10.1098/rsta.2010.0271. PMID 21115521. http://rsta.royalsocietypublishing.org/content/369/1934/217.full.pdf+html. 
  14. ^ United Nations Framework Convention on Climate Change (UNFCCC) (2011), Status of Ratification of the Convention, UNFCCC Secretariat: Bonn, Germany: UNFCCC, http://unfccc.int/essential_background/convention/status_of_ratification/items/2631.php . Most countries in the world are Parties to the United Nations Framework Convention on Climate Change (UNFCCC), which has adopted the 2 °C target. There are currently (as of November 25, 2011) 195 Parties (194 states and 1 regional economic integration organization (the European Union)) to the UNFCCC.
  15. ^ "Article 2". The United Nations Framework Convention on Climate Change.. http://unfccc.int/essential_background/convention/background/items/1353.php. "The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner" , excerpt from the founding international treaty which entered into force on 21 March 1994.
  16. ^ a b United Nations Framework Convention on Climate Change (UNFCCC) (2005) (PDF), Sixth compilation and synthesis of initial national communications from Parties not included in Annex I to the Convention. Note by the secretariat. Executive summary., Geneva (Switzerland): United Nations Office at Geneva, http://unfccc.int/resource/docs/2005/sbi/eng/18.pdf 
  17. ^ Gupta, S. et al. 13.2 Climate change and other related policies, in IPCC AR4 WG3 2007.
  18. ^ International Energy Agency (IEA) (2009) (PDF), World Energy Outlook 2009, Paris, France: IEA, pp. 173–184, ISBN 978-92-64-06130-9, http://www.iea.org/textbase/nppdf/free/2009/weo2009.pdf 
  19. ^ a b United Nations Framework Convention on Climate Change (UNFCCC) (2011) (PDF), Compilation and synthesis of fifth national communications. Executive summary. Note by the secretariat., Geneva (Switzerland): United Nations Office at Geneva, http://unfccc.int/resource/docs/2011/sbi/eng/inf01.pdf 
  20. ^ Adger, W.N., et al., Chapter 17: Assessment of adaptation practices, options, constraints and capacity, Executive summary, in IPCC AR4 WG2 2007.
  21. ^ 6. Generating the funding needed for mitigation and adaptation (PDF), in World Bank (2010), World Development Report 2010: Development and Climate Change, Washington DC, USA: The International Bank for Reconstruction and Development / The World Bank, pp. 262–263, http://go.worldbank.org/BKLQ9DSDU0 
  22. ^ a b United Nations Framework Convention on Climate Change (UNFCCC) (2011) (PDF), Conference of the Parties - Sixteenth Session: Decision 1/CP.16: The Cancun Agreements: Outcome of the work of the Ad Hoc Working Group on Long-term Cooperative Action under the Convention (English): Paragraph 4, UNFCCC Secretariat: Bonn, Germany: UNFCCC, p. 3, http://unfccc.int/resource/docs/2010/cop16/eng/07a01.pdf#page=2  "(...) deep cuts in global greenhouse gas emissions are required according to science, and as documented in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, with a view to reducing global greenhouse gas emissions so as to hold the increase in global average temperature below 2 °C above preindustrial levels"
  23. ^ United Nations Environment Programme (UNEP) (November 2011), "Executive Summary" (PDF), Bridging the Emissions Gap: A UNEP Synthesis Report, Nairobi, Kenya: UNEP, p. 8, ISBN 978-92-807-3229-0, http://www.unep.org/pdf/UNEP_bridging_gap.pdf  UNEP Stock Number: DEW/1470/NA
  24. ^ International Energy Agency (IEA) (2011), "Executive Summary (English)" (PDF), World Energy Outlook 2011, Paris, France: IEA, p. 2, http://www.worldenergyoutlook.org/docs/weo2011/executive_summary.pdf 
  25. ^ "Climate Change: A Summary of the Science (Sept 2010)" (PDF). Royal Society (UK). http://royalsociety.org/WorkArea/DownloadAsset.aspx?id=4294972963. 
  26. ^ USGRCP (n.d.). "Key Findings. On (website): Global Climate Change Impacts in the United States". U.S. Global Change Research Program website. http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts/key-findings. Retrieved 2010-04-17. 
  27. ^ IPCC, Summary for Policymakers, Chapter 1: Observed changes in climate and their effects, in IPCC AR4 SYR 2007.
  28. ^ Trenberth et al., Ch. 3, Observations: Atmospheric Surface and Climate Change, Section 3.2.2.2: Urban Heat Islands and Land Use Effects, p. 244, in IPCC AR4 WG1 2007.
  29. ^ Jansen et al., Ch. 6, Palaeoclimate, Section 6.6.1.1: What Do Reconstructions Based on Palaeoclimatic Proxies Show?, pp. 466–478, in IPCC AR4 WG1 2007.
  30. ^ Cole, Steve; Leslie McCarthy. "NASA – NASA Research Finds 2010 Tied for Warmest Year on Record" (Feature). NASA. http://www.nasa.gov/topics/earth/features/2010-warmest-year.html. Retrieved 2011-03-03. 
  31. ^ Hansen, James E.; et al. (12 January 2006). "Goddard Institute for Space Studies, GISS Surface Temperature Analysis". NASA Goddard Institute for Space Studies. http://data.giss.nasa.gov/gistemp/2005/. Retrieved 2007-01-17. 
  32. ^ "State of the Climate: Global Analysis for Annual 2009". 15 January 2010. http://www.ncdc.noaa.gov/sotc/global/2009/13. Retrieved 3 May 2011. 
  33. ^ Jones, Phil. "CRU Information Sheet no. 1: Global Temperature Record". Climatic Research Unit, School of Environmental Sciences, University of East Anglia. http://www.cru.uea.ac.uk/cru/info/warming/. Retrieved 2011-05-03. 
  34. ^ World Meteorological Organization (2011), WMO statement on the status of the global climate in 2010, World Meteorological Organization (WMO), http://www.wmo.int/pages/prog/wcp/wcdmp/statement/documents/1074_en.pdf 
  35. ^ Changnon, Stanley A.; Bell, Gerald D. (2000). El Niño, 1997–1998: The Climate Event of the Century. London: Oxford University Press. ISBN 0-19-513552-0. 
  36. ^ Knight, J.; Kenney, J.J.; Folland, C.; Harris, G.; Jones, G.S.; Palmer, M.; Parker, D.; Scaife, A. et al. (August 2009). "Do Global Temperature Trends Over the Last Decade Falsify Climate Predictions? [in "State of the Climate in 2008""] (PDF). Bull.Amer.Meteor.Soc. 90 (8): S75–S79. http://www.metoffice.gov.uk/media/pdf/j/j/global_temperatures_09.pdf. Retrieved 2011-08-13. 
  37. ^ Global temperature slowdown — not an end to climate change. UK Met Office. http://webarchive.nationalarchives.gov.uk/+/http:/www.metoffice.gov.uk/climatechange/policymakers/policy/slowdown.html. Retrieved 2011-03-20. 
  38. ^ Trenberth et al., Chap 3, Observations: Atmospheric Surface and Climate Change, Executive Summary, p. 237, in IPCC AR4 WG1 2007.
  39. ^ Rowan T. Sutton, Buwen Dong, Jonathan M. Gregory journal=Geophysical Research Letters (2007). Land/sea warming ratio in response to climate change: IPCC AR4 model results and comparison with observations. 34. pp. L02701. doi:10.1029/2006GL028164. http://www.agu.org/pubs/crossref/2007/2006GL028164.shtml. Retrieved 19 September 2007. 
  40. ^ Ehhalt et al., Chapter 4: Atmospheric Chemistry and Greenhouse Gases, Section 4.2.3.1: Carbon monoxide (CO) and hydrogen (H2), p. 256, in IPCC TAR WG1 2001.
  41. ^ Meehl, Gerald A.; et al. (18 March 2005). "How Much More Global Warming and Sea Level Rise" (PDF). Science 307 (5716): 1769–1772. Bibcode 2005Sci...307.1769M. doi:10.1126/science.1106663. PMID 15774757. http://www.sciencemag.org/cgi/reprint/307/5716/1769.pdf. Retrieved 2007-02-11. 
  42. ^ a b c d [Notes-Hegerl-2001] Hegerl et al., Chapter 9: Understanding and Attributing Climate Change, Section 9.4.1.5: The Influence of Other Anthropogenic and Natural Forcings, in IPCC AR4 WG1 2007. "Recent estimates indicate a relatively small combined effect of natural forcings on the global mean temperature evolution of the second half of the 20th century, with a small net cooling from the combined effects of solar and volcanic forcings." p. 690. Does very cite of this material require the quotation? Is material being repeated?
  43. ^ Kaufman, D.; Schneider, D.; McKay, N.; Ammann, C.; Bradley, R.; Briffa, K.; Miller, G.; Otto-Bliesner, B. et al. (2009). "Recent warming reverses long-term arctic cooling". Science 325 (5945): 1236–1239. Bibcode 2009Sci...325.1236K. doi:10.1126/science.1173983. PMID 19729653.  edit
    "Arctic Warming Overtakes 2,000 Years of Natural Cooling". UCAR. 3 September 2009. http://www2.ucar.edu/news/846/arctic-warming-overtakes-2000-years-natural-cooling. Retrieved 8 June 2011. 
    Bello, David (4 September 2009). "Global Warming Reverses Long-Term Arctic Cooling". Scientific American. http://www.scientificamerican.com/article.cfm?id=global-warming-reverses-arctic-cooling. Retrieved 8 June 2011. 
    Mann, M.; Zhang, Z.; Hughes, M.; Bradley, R.; Miller, S.; Rutherford, S.; Ni, F. (2008). "Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia". Proceedings of the National Academy of Sciences of the United States of America 105 (36): 13252–13257. Bibcode 2008PNAS..10513252M. doi:10.1073/pnas.0805721105. PMC 2527990. PMID 18765811. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2527990.  edit
  44. ^ Weart, Spencer (2008). "The Carbon Dioxide Greenhouse Effect". The Discovery of Global Warming. American Institute of Physics. http://www.aip.org/history/climate/co2.htm. Retrieved 21 April 2009. 
  45. ^ a b
  46. ^ Kiehl, J.T.; Trenberth, K.E. (1997). "Earth's Annual Global Mean Energy Budget" (PDF). Bulletin of the American Meteorological Society 78 (2): 197–208. Bibcode 1997BAMS...78..197K. doi:10.1175/1520-0477(1997)078<0197:EAGMEB>2.0.CO;2. ISSN 1520-0477. Archived from the original on 24 June 2008. http://web.archive.org/web/20080624223905/http://www.atmo.arizona.edu/students/courselinks/spring04/atmo451b/pdf/RadiationBudget.pdf. Retrieved 21 April 2009. 
  47. ^ Schmidt, Gavin (6 Apr 2005). "Water vapour: feedback or forcing?". RealClimate. http://www.realclimate.org/index.php?p=142. Retrieved 21 April 2009. 
  48. ^ Russell, Randy (16 May 2007). "The Greenhouse Effect & Greenhouse Gases". University Corporation for Atmospheric Research Windows to the Universe. http://www.windows.ucar.edu/tour/link=/earth/climate/greenhouse_effect_gases.html&edu=high. Retrieved 27 Dec 2009. 
  49. ^ EPA (2007). "Recent Climate Change: Atmosphere Changes". Climate Change Science Program. United States Environmental Protection Agency. http://www.epa.gov/climatechange/science/recentac.html. Retrieved 21 April 2009. 
  50. ^ Spahni, Renato; et al. (November 2005). "Atmospheric Methane and Nitrous Oxide of the Late Pleistocene from Antarctic Ice Cores". Science 310 (5752): 1317–1321. Bibcode 2005Sci...310.1317S. doi:10.1126/science.1120132. PMID 16311333. 
  51. ^ Siegenthaler, Urs; et al. (November 2005). "Stable Carbon Cycle–Climate Relationship During the Late Pleistocene" (PDF). Science 310 (5752): 1313–1317. Bibcode 2005Sci...310.1313S. doi:10.1126/science.1120130. PMID 16311332. http://www.sciencemag.org/cgi/content/abstract/310/5752/1313. Retrieved 25 August 2010. 
  52. ^ Petit, J. R.; et al. (3 June 1999). "Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica" (PDF). Nature 399 (6735): 429–436. Bibcode 1999Natur.399..429P. doi:10.1038/20859. http://www.daycreek.com/dc/images/1999.pdf. Retrieved 27 December 2009. 
  53. ^ Lüthi, D.; Le Floch, M.; Bereiter, B.; Blunier, T.; Barnola, J. M.; Siegenthaler, U.; Raynaud, D.; Jouzel, J. et al. (2008). "High-resolution carbon dioxide concentration record 650,000–800,000 years before present". Nature 453 (7193): 379–382. Bibcode 2008Natur.453..379L. doi:10.1038/nature06949. PMID 18480821.  edit
  54. ^ Pearson, PN; Palmer, MR (2000). "Atmospheric carbon dioxide concentrations over the past 60 million years". Nature 406 (6797): 695–699. doi:10.1038/35021000. PMID 10963587. 
  55. ^ IPCC, Summary for Policymakers, Concentrations of atmospheric greenhouse gases ..., p. 7, in IPCC TAR WG1 2001.
  56. ^ Le Treut et al., Chap. 1, Historical Overview of Climate Change Science, Section 1.3.1.2: Intensities, in IPCC AR4 WG3 2007.
  57. ^ a b c NRC (2008). "Understanding and Responding to Climate Change". Board on Atmospheric Sciences and Climate, US National Academy of Sciences. p. 2. http://dels.nas.edu/resources/static-assets/materials-based-on-reports/booklets/climate_change_2008_final.pdf. Retrieved 2010-11-09. 
  58. ^ a b World Bank (2010). World Development Report 2010: Development and Climate Change. The International Bank for Reconstruction and Development / The World Bank, 1818 H Street NW, Washington DC 20433. doi:10.1596/978-0-8213-7987-5. ISBN 978-0-8213-7987-5. http://go.worldbank.org/BKLQ9DSDU0. Retrieved 2010-04-06. 
  59. ^ Banuri et al., Chapter 3: Equity and Social Considerations, Section 3.3.3: Patterns of greenhouse gas emissions, and Box 3.1, pp. 92–93 in IPCC SAR WG3 1996.
  60. ^ a b c Liverman, D.M. (2008). "Conventions of climate change: constructions of danger and the dispossession of the atmosphere" (PDF). Journal of Historical Geography 35 (2): 279–296. doi:10.1016/j.jhg.2008.08.008. http://www.environment.arizona.edu/files/env/profiles/liverman/liverman-2009-jhg.pdf. Retrieved 2011-05-10. 
  61. ^ Fisher et al., Chapter 3: Issues related to mitigation in the long-term context, Section 3.1: Emissions scenarios: Issues related to mitigation in the long term context??, in IPCC AR4 WG3 2007.
  62. ^ Morita, Chapter 2: Greenhouse Gas Emission Mitigation Scenarios and Implications, Section 2.5.1.4: Emissions and Other Results of the SRES Scenarios, in IPCC TAR WG3 2001.
  63. ^ Rogner et al., Introduction, Figure 1.7, in IPCC AR4 WG3 2007.
  64. ^ IPCC, Summary for Policymakers, Introduction, paragraph 6, in IPCC TAR WG3 2001.
  65. ^ Prentence et al., Chapter 3: The Carbon Cycle and Atmospheric Carbon DioxideExecutive Summary, in IPCC TAR WG1 2001.
  66. ^ Newell, P.J., 2000: Climate for change: non-state actors and the global politics of greenhouse. Cambridge University Press, ISBN 0521632501.
  67. ^ Talk of the Nation. ""Americans Fail the Climate Quiz"". Npr.org. http://www.npr.org/2010/12/03/131785444/Americans-Fail-The-Climate-Quiz. Retrieved 2011-12-27. 
  68. ^ Shindell, Drew; Faluvegi, Greg; Lacis, Andrew; Hansen, James; Ruedy, Reto; Aguilar, Elliot (2006). "Role of tropospheric ozone increases in 20th-century climate change". Journal of Geophysical Research 111 (D8): D08302. Bibcode 2006JGRD..11108302S. doi:10.1029/2005JD006348. 
  69. ^ Mitchell et al., Chapter 12: Detection of Climate Change and Attribution of Causes Detection of Climate Change and Attribution of Causes: Space-time studies, in IPCC TAR WG1 2001.
  70. ^ Hansen, J; Sato, M; Ruedy, R; Lacis, A; Oinas, V (2000). "Global warming in the twenty-first century: an alternative scenario". Proc. Natl. Acad. Sci. U.S.A. 97 (18): 9875–80. Bibcode 2000PNAS...97.9875H. doi:10.1073/pnas.170278997. PMC 27611. PMID 10944197. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=27611. 
  71. ^ Ramanathan, V.; Carmichael, G. (2008). "Global and regional climate changes due to black carbon". Nature Geosciences 1 (4): 221–227. Bibcode 2008NatGe...1..221R. doi:10.1038/ngeo156. 
  72. ^ Lohmann, U. & J. Feichter (2005). "Global indirect aerosol effects: a review". Atmos. Chem. Phys. 5 (3): 715–737. doi:10.5194/acp-5-715-2005. http://www.atmos-chem-phys.net/5/715/2005/acp-5-715-2005.html. 
  73. ^ Twomey, S. (1977). "Influence of pollution on shortwave albedo of clouds". J. Atmos. Sci. 34 (7): 1149–1152. Bibcode 1977JAtS...34.1149T. doi:10.1175/1520-0469(1977)034<1149:TIOPOT>2.0.CO;2. ISSN 1520-0469. 
  74. ^ Albrecht, B. (1989). "Aerosols, cloud microphysics, and fractional cloudiness". Science 245 (4923): 1227–1239. Bibcode 1989Sci...245.1227A. doi:10.1126/science.245.4923.1227. PMID 17747885. 
  75. ^ IPCC, Summary for Policymakers, in IPCC AR4 WG1.
  76. ^ Ramanathan, V; Chung, C; Kim, D; Bettge, T; Buja, L; Kiehl, JT; Washington, WM; Fu, Q et al.; et al. (2005). "Atmospheric brown clouds: Impacts on South Asian climate and hydrological cycle". Proc. Natl. Acad. Sci. 102 (15): 5326–5333. Bibcode 2005PNAS..102.5326R. doi:10.1073/pnas.0500656102. PMC 552786. PMID 15749818. http://www.pnas.org/content/102/15/5326.abstract. 
  77. ^ Ramanathan, V., et al. (2008). "Report Summary" (PDF). Atmospheric Brown Clouds: Regional Assessment Report with Focus on Asia. United Nations Environment Programme. http://www.rrcap.unep.org/abc/impact/files/ABC_Report_Summary_Final.pdf. 
  78. ^ Ramanathan, V., et al. (2008). "Part III: Global and Future Implications" (PDF). Atmospheric Brown Clouds: Regional Assessment Report with Focus on Asia. United Nations Environment Programme. http://www.rrcap.unep.org/abc/publication/Part%20III.pdf. 
  79. ^ National Research Council (1994). Solar Influences On Global Change. Washington, D.C.: National Academy Press. p. 36. ISBN 0-309-05148-7. http://books.nap.edu/openbook.php?record_id=4778&page=R1. 
  80. ^ Lockwood, Mike; Fröhlich, Claus (8 June 2008). "Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature. II. Different reconstructions of the total solar irradiance variation and dependence on response time scale". Proc. R. Soc. A 464 (2094): 1367–85. Bibcode 2008RSPSA.464.1367L. doi:10.1098/rspa.2007.0347. http://rspa.royalsocietypublishing.org/content/464/2094/1367.abstract. 
  81. ^ Duffy, Santer and Wigley, "Solar variability does not explain late-20th-century warming" Physics Today, January, 2009, pp 48–49. The authors respond to recent assertions by Nicola Scafetta and Bruce West that solar forcing "might account" for up to about half of 20th-century warming.
  82. ^ Hansen, J. (2002). "Climate forcings in Goddard Institute for Space Studies SI2000 simulations". Journal of Geophysical Research 107 (D18): 4347. Bibcode 2002JGRD..107.4347H. doi:10.1029/2001JD001143. 
  83. ^ Hansen, J. (2005). "Efficacy of climate forcings". Journal of Geophysical Research 110 (D18): D18104. Bibcode 2005JGRD..11018104H. doi:10.1029/2005JD005776. 
  84. ^ Randel, William J.; Shine, Keith P.; Austin, John; Barnett, John; Claud, Chantal; Gillett, Nathan P.; Keckhut, Philippe; Langematz, Ulrike et al. (2009). "An update of observed stratospheric temperature trends". Journal of Geophysical Research 114 (D2): D02107. Bibcode 2009JGRD..11402107R. doi:10.1029/2008JD010421. 
  85. ^ Marsh, Nigel; Henrik, Svensmark (November 2000). "Cosmic Rays, Clouds, and Climate" (PDF). Space Science Reviews 94 (1–2): 215–230. doi:10.1023/A:1026723423896. http://www.dsri.dk/~hsv/SSR_Paper.pdf. Retrieved 2007-04-17. 
  86. ^ Lockwood, Mike; Claus Fröhlich (2007). "Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature" (PDF). Proceedings of the Royal Society A 463 (2086): 2447. Bibcode 2007RSPSA.463.2447L. doi:10.1098/rspa.2007.1880. Archived from the original on 26 September 2007. http://web.archive.org/web/20070926023811/http://www.pubs.royalsoc.ac.uk/media/proceedings_a/rspa20071880.pdf. Retrieved 2007-07-21. "Our results show that the observed rapid rise in global mean temperatures seen after 1985 cannot be ascribed to solar variability, whichever of the mechanisms is invoked and no matter how much the solar variation is amplified" 
  87. ^ T Sloan and A W Wolfendale (2008). "Testing the proposed causal link between cosmic rays and cloud cover". Environ. Res. Lett. 3 (2): 024001. Bibcode 2008ERL.....3d4001S. doi:10.1088/1748-9326/3/2/024001. http://www.iop.org/EJ/abstract/1748-9326/3/2/024001/. 
  88. ^ Pierce, J.R. and P.J. Adams (2009). "Can cosmic rays affect cloud condensation nuclei by altering new particle formation rates?". Geophysical Research Letters 36 (9): L09820. Bibcode 2009GeoRL..3609820P. doi:10.1029/2009GL037946. 
  89. ^ Jaggard, Victoria. "Sun Headed Into Hibernation, Solar Studies Predict." National Geographic News, 14 June 2011.
  90. ^ Lenton, T. M.; Held, H.; Kriegler, E.; Hall, J. W.; Lucht, W.; Rahmstorf, S.; Schellnhuber, H. J. (Feb 2008). "Tipping elements in the Earth's climate system" (Free full text). Proceedings of the National Academy of Sciences 105 (6): 1786–1793. Bibcode 2008PNAS..105.1786L. doi:10.1073/pnas.0705414105. PMC 2538841. PMID 18258748. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=18258748.  edit
  91. ^ a b c d e KEVIN SCHAEFER, TINGJUN ZHANG, LORI BRUHWILER, ANDREW P. BARRETT (2011). "Amount and timing of permafrost carbon release in response to climate warming". Tellus Series B 63 (2): 165–180. Bibcode 2011TellB..63..165S. doi:10.1111/j.1600-0889.2011.00527.x. 
  92. ^ a b Romm, Joe (17 February 2011). "NSIDC bombshell: Thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100". ThinkProgress. http://thinkprogress.org/romm/2011/02/17/207552/nsidc-thawing-permafrost-will-turn-from-carbon-sink-to-source-in-mid-2020s-releasing-100-billion-tons-of-carbon-by-2100/. Retrieved 2011-07-27. 
  93. ^ "Thawing permafrost likely will accelerate global warming, study finds". Sciencedaily.com. 17 February 2011. doi:10.1111/j.1600-0889.2011.00527.x. http://www.sciencedaily.com/releases/2011/02/110216132100.htm. Retrieved 2011-07-27. 
  94. ^ Hunting for methane with Katey Walter Anthony. Univ Alaska Fairbanks, Marketing and Communications. http://www.youtube.com/watch?v=YegdEOSQotE. Retrieved 31 May 2011. 
  95. ^ Isaksen, Ivar S. A.; Michael Gauss, Gunnar Myhre, Katey M. Walter, and Anthony and Carolyn Ruppel (20 April 2011). "Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions". Global Biogeochemical Cycles 25 (2). Bibcode 2011GBioC..25B2002I. doi:10.1029/2010GB003845. http://www.atmos.washington.edu/academics/classes/2011Q2/558/IsaksenGB2011.pdf. 
  96. ^ IPCC, Glossary A-D: "Climate Model", in IPCC AR4 SYR 2007.
  97. ^ Denman et al., Chapter 7: Couplings Between Changes in the Climate System and Biogeochemistry, Sec. ??, in IPCC AR4 WG1 2007.
  98. ^ Hansen, James (2000). "Climatic Change: Understanding Global Warming". In Robert Lanza. One World: The Health & Survival of the Human Species in the 21st century. Health Press (New Mexico). pp. 173–190. ISBN 0-929173-33-3. http://books.google.com/?id=sx6DFr8rbpIC&dq=robert+lanza&printsec=frontcover. Retrieved 2007-08-18. 
  99. ^ Stocker et al., Chapter 7: Physical Climate Processes and Feedbacks, Section 7.2.2: Cloud Processes and Feedbacks, in IPCC TAR WG1 2001.
  100. ^ Torn, Margaret; Harte, John (2006). "Missing feedbacks, asymmetric uncertainties, and the underestimation of future warming". Geophysical Research Letters 33 (10): L10703. Bibcode 2006GeoRL..3310703T. doi:10.1029/2005GL025540. http://www.agu.org/pubs/crossref/2006/2005GL025540.shtml. Retrieved 2007-03-04. 
  101. ^ Harte, John; et al. (2006). "Shifts in plant dominance control carbon-cycle responses to experimental warming and widespread drought". Environmental Research Letters 1 (1): 014001. Bibcode 2006ERL.....1a4001H. doi:10.1088/1748-9326/1/1/014001. http://www.iop.org/EJ/article/1748-9326/1/1/014001/erl6_1_014001.html. Retrieved 2007-05-02. 
  102. ^ Scheffer, Marten; et al. (2006). "Positive feedback between global warming and atmospheric CO2 concentration inferred from past climate change". Geophysical Research Letters 33 (10): L10702. Bibcode 2006GeoRL..3310702S. doi:10.1029/2005gl025044. http://www.pik-potsdam.de/~victor/recent/scheffer_etal_T_CO2_GRL_in_press.pdf. Retrieved 2007-05-04. 
  103. ^ Randall et al., Chapter 8, Climate Models and Their Evaluation, Sec. ?? in IPCC AR4 WG1 2007.
  104. ^ IPCC, Summary for Policymakers, in IPCC TAR WG1 2001.
  105. ^ Stroeve, J., et al. (2007). "Arctic sea ice decline: Faster than forecast". Geophysical Research Letters 34 (9): L09501. Bibcode 2007GeoRL..3409501S. doi:10.1029/2007GL029703. 
  106. ^ Wentz,FJ, et al. (2007). "How Much More Rain Will Global Warming Bring?". Science 317 (5835): 233–5. Bibcode 2007Sci...317..233W. doi:10.1126/science.1140746. PMID 17540863. http://www.sciencemag.org/cgi/content/abstract/317/5835/233. 
  107. ^ Liepert, Beate G.; Previdi (2009). "Do Models and Observations Disagree on the Rainfall Response to Global Warming?". Journal of Climate 22 (11): 3156. Bibcode 2009JCli...22.3156L. doi:10.1175/2008JCLI2472.1. http://journals.ametsoc.org/doi/abs/10.1175/2008JCLI2472.1. "Recently analyzed satellite-derived global precipitation datasets from 1987 to 2006 indicate an increase in global-mean precipitation of 1.1%–1.4% decade−1. This trend corresponds to a hydrological sensitivity (HS) of 7% K−1 of global warming, which is close to the Clausius–Clapeyron (CC) rate expected from the increase in saturation water vapor pressure with temperature. Analysis of two available global ocean evaporation datasets confirms this observed intensification of the atmospheric water cycle. The observed hydrological sensitivity over the past 20-yr period is higher by a factor of 5 than the average HS of 1.4% K−1 simulated in state-of-the-art coupled atmosphere–ocean climate models for the twentieth and twenty-first centuries." 
  108. ^ IPCC, Glossary A-D: "Detection and attribution", in IPCC AR4 WG1 2007. See also Hegerl et al., Section 9.1.2: What are Climate Change Detection and Attribution?, in IPCC AR4 WG1 2007.
  109. ^ Rosenzweig et al., Chapter 1: Assessment of Observed Changes and Responses in Natural and Managed Systems Section 1.2 Methods of detection and attribution of observed changes, in IPCC AR4 WG2 2007 .
  110. ^ a b IPCC, Synthesis Report Summary for Policymakers, Section 1: Observed changes in climate and their effects, in IPCC AR4 SYR 2007.
  111. ^ IPCC, Synthesis Report Summary for Policymakers, Section 2: Causes of change, in IPCC AR4 SYR 2007.
  112. ^ a b c IPCC, Synthesis Report Summary for Policymakers, Section 3: Projected climate change and its impacts, in IPCC AR4 SYR 2007.
  113. ^ IPCC, WG2 Summary for Policymakers, Magnitudes of impact, in IPCC AR4 WG2 2007.
  114. ^ Wang, M; J.E. Overland (2009). "A sea ice free summer Arctic within 30 years?". Geophys. Res. Lett 36 (7). Bibcode 2009GeoRL..3607502W. doi:10.1029/2009GL037820. http://www.pmel.noaa.gov/publications/search_abstract.php?fmContributionNum=3261. Retrieved 2 May 2011. 
  115. ^ Fischlin, et al., Chapter 4: Ecosystems, their Properties, Goods and Services, Executive Summary, p. 213, in IPCC AR4 WG2 2007. Executive summary not present in on-line text; see pdf.
  116. ^ Schneider et al., Chapter 19: Assessing Key Vulnerabilities and the Risk from Climate Change, Section 19.3.4: Ecosystems and biodiversity, in IPCC AR4 WG2 2007.
  117. ^ Wilbanks et al., Chapter 7: Industry, Settlement and Society, Executive Summary, in IPCC AR4 WG2 2007.
  118. ^ a b x Schneider et al., Chapter 19: Assessing Key Vulnerabilities and the Risk from Climate Change, Section 19.3.3: Regional vulnerabilities, in IPCC AR4 WG2 2007.
  119. ^ Schneider et al., Chapter 19: Assessing Key Vulnerabilities and the Risk from Climate Change, Section 19.3.7: Update on ‘Reasons for Concern’, in IPCC AR4 WG2 2007.
  120. ^ a b x Schneider et al., Chapter 19: Assessing Key Vulnerabilities and the Risk from Climate Change, Table 19.1, in IPCC AR4 WG2 2007.
  121. ^ IPCC, Synthesis Report Summary for Policymakers, Section 5.2: Key vulnerabilities, impacts and risks – long-term perspectives, in IPCC AR4 SYR 2007.
  122. ^ Schneider et al., Chapter 19: Assessing Key Vulnerabilities and the Risk from Climate Change, Section 19.3.2.1: Agriculture, in IPCC AR4 WG2 2007.
  123. ^ Yohe, et al., Chapter 20: Perspectives on Climate Change and Sustainability, Figure 20.3, in IPCC AR4 WG2 2007.
  124. ^ Stern, N. (2006). "6.2 What existing models calculate and include" (PDF). 6 Economic modelling of climate-change impacts. Stern Review Report on the Economics of Climate Change (pre-publication edition). HM Treasury website. pp. 147–148. http://www.hm-treasury.gov.uk/d/Chapter_6_Economic_modelling_of_climate-change_impacts.pdf. Retrieved 2011-04-28. 
  125. ^ IPCC, Glossary J-P: "Mitigation", in IPCC AR4 WG3 2007.
  126. ^ a b IPCC, Synthesis Report Summary for Policymakers, Section 4: Adaptation and mitigation options, in IPCC AR4 SYR 2007.
  127. ^ IPCC, Summary for Policymakers, in IPCC AR4 WG1 2007.
  128. ^ National Academy calls on nation to “substantially reduce greenhouse gas emissions” starting ASAP | ThinkProgress
  129. ^ http://www.iea.org/index_info.asp?id=1959
  130. ^ Robinson, Simon (22 January 2010). "How to reduce Carbon emmissions: Capture and Store It?". Time. http://www.time.com/time/specials/packages/article/0,28804,1954176_1954175,00.html. Retrieved 2010-08-09. 
  131. ^ Smit et al., Chapter 18: Adaptation to Climate Change in the Context of Sustainable Development and Equity, Section 18.2.3: Adaptation Types and Forms, in IPCC TAR WG2 2001.
  132. ^ a b Barker et al., Chapter 11: Mitigation from a cross-sectoral perspective Section 11.2.2: Ocean fertilization and other geo-engineering options, in IPCC AR4 WG3 2007.
  133. ^ a b IPCC, Summary for Policymakers,C. Mitigation in the short and medium term (until 2030) - paragraph 17, in IPCC AR4 WG3 2007.
  134. ^ "Geoengineering the climate: science, governance and uncertainty". The Royal Society. 1 September 2009. http://royalsociety.org/Geoengineering-the-climate/. Retrieved 26 February 2011. 
  135. ^ Banuri, et al., Chapter 3: Equity and Social Considerations, Section 3.1.2: Concepts of equity, p. 85 et seq. in IPCC SAR WG3 1996.
  136. ^ Banuri, et al., Chapter 3: Equity and Social Considerations, Section ??, p. 83, in IPCC SAR WG3 1996.
  137. ^ Boykoff, M.; Boykoff, J. (2004). "Balance as bias: global warming and the US prestige press1" (Full free text). Global Environmental Change Part A 14 (2): 125–136. doi:10.1016/j.gloenvcha.2003.10.001. http://www.eci.ox.ac.uk/publications/downloads/boykoff04-gec.pdf.  edit
  138. ^ Oreskes, Naomi; Conway, Erik. Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming (first ed.). Bloomsbury Press. ISBN 978-1-596-91610-4. 
  139. ^ Julie Brigham-Grette et al. (September 2006). "Petroleum Geologists' Award to Novelist Crichton Is Inappropriate" (PDF). Eos 87 (36). http://www.agu.org/fora/eos/pdfs/2006EO360008.pdf. Retrieved 2007-01-23. "The AAPG stands alone among scientific societies in its denial of human-induced effects on global warming." 
  140. ^ DiMento, Joseph F. C.; Doughman, Pamela M. (2007). Climate Change: What It Means for Us, Our Children, and Our Grandchildren. The MIT Press. p. 68. ISBN 978-0-262-54193-0. 
  141. ^ Aaron M. McCright and Riley E. Dunlap, "Challenging Global Warming as a Social Problem: An Analysis of the Conservative Movement's Counter-Claims," Social Problems, Nov 2000, Vol. 47 Issue 4, pp 499-522 in JSTOR
  142. ^ IPCC, Synthesis of Scientific-Technical Information, paragraph 4.1, pdf p. 8, in IPCC SAR SYR 1996.
  143. ^ Granger Morgan, M. (Lead Author), H. Dowlatabadi, M. Henrion, D. Keith, R. Lempert, S. McBride, M. Small and T. Wilbanks (Contributing Authors) (2009). "BOX NT.1 Summary of Climate Change Basics". Non-Technical Summary. Synthesis and Assessment Product 5.2: Best practice approaches for characterizing, communicating, and incorporating scientific uncertainty in decisionmaking. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. Washington D.C., USA.: National Oceanic and Atmospheric Administration. p. 11. http://www.globalchange.gov/publications/reports/scientific-assessments/saps/311. Retrieved 2011-06-01. 
  144. ^ UNFCCC (n.d.). "Essential Background". UNFCCC website. http://unfccc.int/essential_background/items/2877.php. Retrieved 2010-05-18. 
  145. ^ UNFCCC (n.d.). "Full text of the Convention, Article 2". UNFCCC website. http://unfccc.int/essential_background/convention/background/items/1353.php. Retrieved 2010-05-18. 
  146. ^ Rogner et al., Chapter 1: Introduction, Executive summary, in IPCC AR4 WG3 2007.
  147. ^ Raupach, R.; Marland, G.; Ciais, P.; Le Quéré, C.; Canadell, G.; Klepper, G.; Field, B. (Jun 2007). "Global and regional drivers of accelerating CO2 emissions" (Free full text). Proceedings of the National Academy of Sciences 104 (24): 10288–10293. Bibcode 2007PNAS..10410288R. doi:10.1073/pnas.0700609104. ISSN 0027-8424. PMC 1876160. PMID 17519334. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=17519334.  edit
  148. ^ a b Dessai, S. (2001). "The climate regime from The Hague to Marrakech: Saving or sinking the Kyoto Protocol?" (PDF). Tyndall Centre Working Paper 12. Tyndall Centre website. http://www.tyndall.ac.uk/sites/default/files/wp12.pdf. Retrieved 2010-05-05. 
  149. ^ Grubb, M. (July–September 2003). "The Economics of the Kyoto Protocol" (PDF). World Economics 4 (3): 144–145. http://www.econ.cam.ac.uk/rstaff/grubb/publications/J36.pdf. Retrieved 2010-03-25. 
  150. ^ a b UNFCCC (n.d.). "Kyoto Protocol". UNFCCC website. http://unfccc.int/kyoto_protocol/items/2830.php. Retrieved 2011-05-21. 
  151. ^ Müller, Benito (February 2010) (PDF). Copenhagen 2009: Failure or final wake-up call for our leaders? EV 49. Dr Benito Müller's web page on the Oxford Institute for Energy Studies website. p. i. ISBN 978190755046. http://www.oxfordenergy.org/pdfs/EV49.pdf. Retrieved 2010-05-18. 
  152. ^ a b United Nations Environment Programme (November 2010). "Technical summary" (PDF). The Emissions Gap Report: Are the Copenhagen Accord pledges sufficient to limit global warming to 2 °C or 1.5 °C? A preliminary assessment (advance copy). UNEP website. http://www.unep.org/publications/ebooks/emissionsgapreport/pdfs/The_EMISSIONS_GAP_REPORT.pdf. Retrieved 2011-05-11.  This publication is also available in e-book format
  153. ^ UNFCCC (30 March 2010). "Decision 2/CP. 15 Copenhagen Accord. In: Report of the Conference of the Parties on its fifteenth session, held in Copenhagen from 7 to 19 December 2009. Addendum. Part Two: Action taken by the Conference of the Parties at its fifteenth session" (PDF). United Nations Office at Geneva, Switzerland. p. 5. http://unfccc.int/documentation/documents/advanced_search/items/3594.php?rec=j&priref=600005735#beg. Retrieved 2010-05-17. 
  154. ^ "Outcome of the work of the Ad Hoc Working Group on long-term Cooperative Action under the Convention". PRESIDENCIA DE LA REPÚBLICA, MÉXICO. 11 December 2010. p. 2. http://unfccc.int/files/meetings/cop_16/application/pdf/cop16_lca.pdf. Retrieved 12 January 2011. 
  155. ^ a b "69% Say It’s Likely Scientists Have Falsified Global Warming Research - Rasmussen Reports™". Rasmussenreports.com. 2011-08-03. http://www.rasmussenreports.com/public_content/politics/current_events/environment_energy/69_say_it_s_likely_scientists_have_falsified_global_warming_research. Retrieved 2011-12-27. 
  156. ^ Pelham, Brett (22 April 2009). "Awareness, Opinions About Global Warming Vary Worldwide". Gallup. http://www.gallup.com/poll/117772/Awareness-Opinions-Global-Warming-Vary-Worldwide.aspx. Retrieved 2009-07-14. 
  157. ^ "Summary of Findings". Little Consensus on Global Warming. Partisanship Drives Opinion. Pew Research Center. 12 July 2006. http://people-press.org/reports/display.php3?ReportID=280. Retrieved 2007-04-14. 
  158. ^ Crampton, Thomas (4 January 2007). "More in Europe worry about climate than in U.S., poll shows". The New York Times. http://www.nytimes.com/2007/01/04/health/04iht-poll.4102536.html?_r=1. Retrieved 2010-06-09. 
  159. ^ "Public attitudes towards climate change and the impact on transport (January 2011 report)". Department for Transport. 2011. p. 8. http://www.dft.gov.uk/pgr/statistics/datatablespublications/trsnstatsatt/climatejan2011report. Retrieved 3 February 2011. 
  160. ^ Damian Carrington (31 January 2011). "Public belief in climate change weathers storm, poll shows | Environment | guardian.co.uk". The Guardian. UK. http://www.guardian.co.uk/environment/2011/jan/31/public-belief-climate-change. Retrieved 2011-02-04. 
  161. ^ "Fewer Americans See Solid Evidence of Global Warming". Pew Research Center for the People & the Press. 22 October 2009. http://people-press.org/report/556/global-warming. Retrieved 26 February 2011. 
  162. ^ Robin Lloyd (23 February 2011). "Why Are Americans So Ill-Informed about Climate Change?: Scientists and journalists debate why Americans still resist the consensus among research organizations that humans are warming the globe". Scientific American. Nature America, Inc.. http://www.scientificamerican.com/article.cfm?id=why-are-americans-so-ill. Retrieved 26 February 2011. 
  163. ^ "59% Say Scientists Disagree 'Significantly' Over Global Warming - Rasmussen Reports™". Rasmussenreports.com. 2010-04-20. http://www.rasmussenreports.com/public_content/politics/current_events/environment_energy/59_say_scientists_disagree_significantly_over_global_warming. Retrieved 2011-12-27. 
  164. ^ Pugliese, Anita (20 April 2011). "Fewer Americans, Europeans View Global Warming as a Threat". Gallup. http://www.gallup.com/poll/147203/Fewer-Americans-Europeans-View-Global-Warming-Threat.aspx. Retrieved 22 April 2011. 
  165. ^ Ray, Julie; Anita Pugliese (22 April 2011). "Worldwide, Blame for Climate Change Falls on Humans". Gallup.Com. http://www.gallup.com/poll/147242/Worldwide-Blame-Climate-Change-Falls-Humans.aspx. Retrieved 2011-05-03. "People nearly everywhere, including majorities in developed Asia and Latin America, are more likely to attribute global warming to human activities rather than natural causes. The U.S. is the exception, with nearly half (47%) – and the largest percentage in the world – attributing global warming to natural causes." 
  166. ^ Leiserowitz, A.; E. Maibach, C. Roser-Renouf, & N. Smith (2011). Global Warming's Six Americas, May 2011. New Haven CT: Yale Project on Climate Change Communication: Yale University and George Mason University. http://environment.yale.edu/climate/news/SixAmericasMay2011/. 
  167. ^ "It's All in a Name: 'Global Warming' Vs. 'Climate Change'". http://www.sciencedaily.com/releases/2011/03/110308173242.htm. 
  168. ^ IVN. "PPIC survey puts spotlight on environmental issues." 1 August 2011
  169. ^ "Angus Reid Public Opinion poll conducted 25 August through 2 September 2011" (PDF). http://www.angus-reid.com/wp-content/uploads/2011/09/2011.09.12_Climate.pdf. Retrieved 2011-12-27. 
  170. ^ a b Royal Society (13 April 2005). "Letter from The Royal Society: A GUIDE TO FACTS AND FICTIONS ABOUT CLIMATE CHANGE: Misleading arguments: Many scientists do not think that climate change is a problem. Some scientists have signed petitions stating that climate change is not a problem.". Economic Affairs – Written Evidence. The Economics of Climate Change, the Second Report of the 2005–2006 session, produced by the UK Parliament House of Lords Economics Affairs Select Committee. UK Parliament website. http://www.publications.parliament.uk/pa/ld200506/ldselect/ldeconaf/12/12we24.htm. Retrieved 2011-07-09.  This document is also available in PDF format
  171. ^ Academia Brasileira de Ciéncias (Brazil), Royal Society of Canada, Chinese Academy of Sciences, Académie des Sciences (France), Deutsche Akademie der Naturforscher Leopoldina (Germany), Indian National Science Academy, Accademia Nazionale dei Lincei (Italy), Science Council of Japan, Academia Mexicana de Ciencias, Russian Academy of Sciences, Academy of Science of South Africa, Royal Society (United Kingdom), National Academy of Sciences (United States of America) (May 2009). "G8+5 Academies’ joint statement: Climate change and the transformation of energy technologies for a low carbon future". US National Academies website. http://www.nationalacademies.org/includes/G8+5energy-climate09.pdf. Retrieved 2010-05-05. 
  172. ^ Weart, S. (July 2009). "The Public and Climate Change (cont. – since 1980). Section: After 1988". American Institute of Physics website. http://www.aip.org/history/climate/public2.htm. Retrieved 2010-05-05. 
  173. ^ SEPP (n.d.). "Frequently Asked Questions About Climate Change". Science & Environmental Policy Project (SEPP) website. Archived from the original on 11 May 2008. http://web.archive.org/web/20080511011611/http://www.sepp.org/FAQ/faq.html. Retrieved 2010-05-05. 
  174. ^ Begley, Sharon (13 August 2007). "The Truth About Denial". Newsweek. http://www.newsweek.com/id/32482. Retrieved 2007-08-13. 
  175. ^ Adams, David (20 September 2006). "Royal Society tells Exxon: stop funding climate change denial". The Guardian. London. http://www.guardian.co.uk/environment/2006/sep/20/oilandpetrol.business. Retrieved 2007-08-09. 
  176. ^ "Exxon cuts ties to global warming skeptics". MSNBC. 12 January 2007. http://www.msnbc.msn.com/id/16593606. Retrieved 2007-05-02. 
  177. ^ Sandell, Clayton (3 January 2007). "Report: Big Money Confusing Public on Global Warming". ABC. http://abcnews.go.com/Technology/Business/story?id=2767979&page=1. Retrieved 2007-04-27. 
  178. ^ "About DBCCA". Deutsche Bank: DB Climate Change Advisors. Frankfurt am Main: Deutsche Bank AG. 12 May 2010. http://www.dbcca.com/dbcca/EN/about-us.jsp. Retrieved 2010-11-05. "DB Climate Change Advisors is the brand name for the institutional climate change investment division of Deutsche Asset Management, the asset management arm of Deutsche Bank AG." 
  179. ^ "Investment Research". Deutsche Bank: DB Climate Change Advisors. Frankfurt am Main: Deutsche Bank AG. 2 November 2010. http://www.dbcca.com/dbcca/EN/investment_research.jsp. Retrieved 2010-11-05. 
  180. ^ Carr, Mary-Elena; Kate Brash, Robert F. Anderson (September 2010). "Climate Change: Addressing the Major Skeptic Arguments" (PDF). DB Climate Change Advisors: Deutsche Bank Group. p. 55. http://www.dbcca.com/dbcca/EN/_media/DBCCAColumbiaSkepticPaper090710.pdf. Retrieved 2010-11-05. "The planet is warming and it is likely to continue to warm as a consequence of increased greenhouse gas emissions." 
  181. ^ "New Report Provides Authoritative Assessment of National, Regional Impacts of Global Climate Change" (PDF) (Press release). U.S. Global Change Research Program. 6 June 2009. http://www.globalchange.gov/images/cir/pdf/Climate-Impacts-PR_june-6-2009.pdf. Retrieved 2009-06-27. 
  182. ^ Reuters (18 May 2007). "Greenpeace: Exxon still funding climate skeptics". USA Today. http://www.usatoday.com/weather/climate/globalwarming/2007-05-18-greenpeace-exxon_N.htm. Retrieved 21 Jan 2010. 
  183. ^ "Global Warming Resolutions at U.S. Oil Companies Bring Policy Commitments from Leaders, and Record High Votes at Laggards" (Press release). Ceres. 13 May 2004. http://www.csrwire.com/press/press_release/23395-Global-Warming-Resolutions-at-U-S-Oil-Companies-Bring-Policy-Commitments-from-Leaders-and-Record-High-Votes-at-Laggards. Retrieved 2010-03-04. 
  184. ^ Stefan (28 July 2010). "Happy 35th birthday, global warming!". RealClimate. http://www.realclimate.org/index.php/archives/2010/07/happy-35th-birthday-global-warming/. Retrieved 10 August 2010. "[Broecker's article is] the first of over 10,000 papers for this search term according to the ISI database of journal articles" 
  185. ^ Johnson, Brad (3 August 2010). "Wally's World". Foreign Policy. http://www.foreignpolicy.com/articles/2010/08/03/wallys_world. Retrieved 10 August 2010. 
  186. ^ Wallace Broecker, "Climatic Change: Are We on the Brink of a Pronounced Global Warming?" Science, vol. 189 (8 August 1975), 460–463.
  187. ^ a b c d Erik Conway. "What's in a Name? Global Warming vs. Climate Change", NASA, 5 December 2008
  188. ^ National Academy of Science, Carbon Dioxide and Climate, Washington, D.C., 1979, p. vii.
  189. ^ U.S. Senate, Committee on Energy and Natural Resources, "Greenhouse Effect and Global Climate Change, part 2" 100th Cong., 1st sess., 23 June 1988, p. 44.
  190. ^ "SCI/TECH | Science academies back Kyoto". BBC News. 17 May 2001. http://news.bbc.co.uk/1/hi/sci/tech/1335872.stm. Retrieved 2011-07-27. 
  191. ^ IPCC, Synthesis Report Summary for Policymakers, Introduction, in IPCC AR4 SYR 2007.

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