Climate change

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Global mean surface temperature anomaly 1850 to 2006
Mean surface temperature anomalies during the period 1995 to 2004 with respect to the average temperatures from 1940 to 1980

Global warming is the observed increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation.

Global average air temperature near Earth's surface rose 0.74 ± 0.18 °C (1.3 ± 0.32 °F) during the last century. The Intergovernmental Panel on Climate Change (IPCC) concludes, "most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations,"[1] which leads to warming of the surface and lower atmosphere by increasing the greenhouse effect. Other phenomena such as solar variation and volcanoes have probably had a warming effect from pre-industrial times to 1950, but a cooling effect since 1950.[1] These conclusions have been endorsed by at least 30 scientific societies and academies of science, including all of the national academies of science of the major industrialized countries. The American Association of Petroleum Geologists is the only scientific society that rejects these conclusions,[2][3] but a few individual scientists also disagree with parts of it.[4]

Climate models referenced by the IPCC predict that global surface temperatures are likely to increase by 1.1 to 6.4 °C (2.0 to 11.5 °F) between 1990 and 2100.[1] The range of values reflects the use of differing scenarios of future greenhouse gas emissions as well as uncertainties regarding climate sensitivity. Although most studies focus on the period up to 2100, warming and sea level rise are expected to continue for more than a millennium even if no further greenhouse gases are released after this date.[1] This reflects the long average atmospheric lifetime of carbon dioxide (CO2).

An increase in global temperatures can in turn cause other changes, including sea level rise, and changes in the amount and pattern of precipitation. There may also be increases in the frequency and intensity of extreme weather events, though it is difficult to connect specific events to global warming. Other consequences may include changes in agricultural yields, glacier retreat, reduced summer streamflows, species extinctions and increases in the ranges of disease vectors.

Remaining scientific uncertainties include the exact degree of climate change expected in the future, and especially how changes will vary from region to region across the globe. A political and public debate also has yet to be resolved, regarding whether anything should be done, and what could be cost-effectively done to reduce or reverse future warming, or to deal with the expected consequences. Most national governments have signed and ratified the Kyoto Protocol aimed at combating greenhouse gas emissions.

Terminology

The term global warming is a specific example of the broader term climate change, which can also refer to global cooling. In principle, global warming is neutral as to the period or causes, but in both common and scientific usage the term generally refers to recent warming and implies a human influence.[5] The United Nations Framework Convention on Climate Change (UNFCCC) uses the term "climate change" for human-caused change, and "climate variability" for other changes.[6] The term "anthropogenic climate change" is sometimes used when focusing on human-induced changes.

Causes

Main articles: Attribution of recent climate change and scientific opinion on climate change
File:Carbon Dioxide 400kyr-2.png
Carbon dioxide during the last 400,000 years and the rapid rise since the Industrial Revolution; changes in the Earth's orbit around the Sun, known as Milankovitch cycles, are believed to be the pacemaker of the 100,000 year ice age cycle.

The climate system varies through natural, internal processes and in response to variations in external forcing factors including solar activity, volcanic emissions, variations in the earth's orbit (orbital forcing) and greenhouse gases. The detailed causes of the recent warming remain an active field of research, but the scientific consensus[7][8] identifies increased levels of greenhouse gases due to human activity as the main influence. This attribution is clearest for the most recent 50 years, for which the most detailed data are available.

Greenhouse gases create a natural greenhouse effect without which mean temperatures on Earth would be an estimated 33 °C (59 °F) lower, so that Earth would be uninhabitable.[9] It is therefore not correct to say that there is a debate between those who "believe in" and "oppose" the greenhouse effect as such. Rather, the debate concerns the net effect of the addition of greenhouse gases while allowing for associated positive and negative feedback mechanisms.

The primary greenhouse gases are water vapor, carbon dioxide (CO2) and methane (CH4). Water is the most abundant in the atmosphere by concentration, but it is a short-term greenhouse gas and in a dynamic equilibrium in the atmosphere. Great quantities of water can be added to the atmosphere by evaporation or subtracted by precipitation in a period of weeks. Methane is an intermediate-term greenhouse gas and in the atmosphere is converted to CO2 in a period of months to years. CO2 is a long-term greenhouse gas and, once added to the atmosphere can remain in the atmosphere for hundreds of years.

Adding CO2 or CH4 to Earth's atmosphere, with no other changes, will make the planet's surface warmer. The concentration of CO2 in the atmosphere, currently 380 parts per million (ppm), might be naïvely taken to be too low to have much effect. However, the importance of CO2 arises from a feedback effect: a little of the long-term CO2 injected into the atmosphere causes a little warming, which causes a little more of the potent short-term water vapor to be evaporated into the atmosphere, which causes still more warming, which causes more of the potent water vapor to be evaporated, and so forth, until a new dynamic equilibrium concentration of water vapor is reached at a slightly higher humidity and with a much larger greenhouse effect than that due to CO2 alone. This feedback effect is reversed only as the CO2 is slowly removed from the atmosphere.

Another important feedback process is ice-albedo feedback.[10] The increased CO2 in the atmosphere warms the Earth's surface and leads to melting of ice near the poles. As the ice melts, land or open water takes its place. Both land and open water are on average less reflective than ice, and thus absorb more solar radiation. This causes more warming, which in turn causes more melting, and this cycle continues.

Feedback effects due to clouds are an area of ongoing research and debate. Seen from below, water aerosol clouds absorb infrared radiation and so exert a warming effect. Seen from above, the same clouds reflect sunlight and so exert a cooling effect. Increased global water vapor concentration may or may not cause an increase in global average cloud cover. The net effect of clouds thus has not been well modeled. Positive feedback due to release of CO2 and CH4 from thawing permafrost is an additional mechanism contributing to warming. Possible positive feedback due to methane release from melting seabed ices is a further mechanism to be considered.

None of the effects of greenhouse gases are instantaneous. Due to the thermal inertia of the Earth's oceans and slow responses of other indirect effects, the Earth's current climate is not in equilibrium with the forcing imposed by increased greenhouse gases. Climate commitment studies indicate that, even if greenhouse gases were stabilized at present day levels, a further warming of about 0.5 °C (0.9 °F) would still occur.[11]

Contrasting with the consensus view, other hypotheses have been proposed to explain some of the observed increase in global temperatures, including: the warming is within the range of natural variation; the warming is a consequence of coming out of a prior cool period, namely the Little Ice Age; the warming is primarily a result of variances in solar radiation; or the warming is primarily the result of increased activity of the solar magnetic field, which increases shielding of the Earth from cosmic rays which would otherwise cause raindrop nucleation in clouds, which would remove greenhouse-gas water vapor from the atmosphere.

Greenhouse gases in the atmosphere

Main article: Greenhouse effect
Recent increases in atmospheric CO2. The monthly CO2 measurements display small seasonal oscillations in an overall yearly uptrend; each year's maximum is reached during the northern hemisphere's late spring, and declines during the northern hemisphere growing season as plants remove some CO2 from the atmosphere.

The greenhouse effect was discovered by Joseph Fourier in 1824 and was first investigated quantitatively by Svante Arrhenius in 1896. It is the process by which absorption of infrared radiation by atmospheric gases warms a planet's atmosphere and surface.

On Earth, the major natural greenhouse gases are water vapor, which causes about 36–70% of the greenhouse effect (not including clouds); carbon dioxide (CO2), which causes 9–26%; methane (CH4), which causes 4–9%; and ozone, which causes 3–7%.

The atmospheric concentrations of CO2 and CH4 have increased by 31% and 149% respectively above pre-industrial levels since 1750. This is considerably higher than at any time during the last 650,000 years, the period for which reliable data has been extracted from ice cores. From less direct geological evidence it is believed that CO2 values this high were last attained 20 million years ago.[12] About three-quarters of the anthropogenic (man-made) emissions of CO2 to the atmosphere during the past 20 years are due to fossil fuel burning. The rest of the anthropogenic emissions are predominantly due to land-use change, especially deforestation.[13]

Future CO2 levels are expected to rise due to ongoing burning of fossil fuels and land-use change. The rate of rise will depend on uncertain economic, sociological, technological, natural developments, but may be ultimately limited by the availability of fossil fuels. The IPCC Special Report on Emissions Scenarios gives a wide range of future CO2 scenarios, ranging from 541 to 970 parts per million by the year 2100.[14] Fossil fuel reserves are sufficient to reach this level and continue emissions past 2100, if coal, tar sands or methane clathrates are extensively used.[15]

Positive feedback effects such as the expected release of CH4 from the melting of permafrost peat bogs in Siberia (possibly up to 70,000 million tonnes) may lead to significant additional sources of greenhouse gas emissions[16] not included in IPCC's climate models.[17]

Solar variation

Solar variation over the last 30 years
Main article: Solar variation

Variations in solar output, possibly amplified by cloud feedbacks, have been suggested as a possible cause of recent warming.[18] However, a warming of the stratosphere, which has not been observed, would be expected if there were a significant increase in solar activity.[19]

Combined solar variation and volcanoes have probably had a warming effect from pre-industrial times to 1950, but a cooling effect since 1950 [1]. Some research has suggested that the Sun's contribution may have been underestimated. Researchers at Duke University have estimated that the Sun may have minimally contributed about 10–30% of the global surface temperature warming over the period 1980–2002.[20] Similarly, Stott et al. estimate in 2003 that climate models overestimate the relative effect of greenhouse gases compared to solar forcing but also that the cooling effect of volcanic dust and sulfate aerosols has been underestimated.[21] They conclude that even with an enhanced climate sensitivity to solar forcing, most of the warming during the latest decades is attributable to the increases in greenhouse gases.

History

Main article: Temperature record
Curves of reconstructed temperature at two locations in Antarctica and a global record of variations in glacial ice volume. Today's date is on the left side of the graph

Global temperatures on both land and sea have increased by 0.75 °C (1.4 °F) relative to the period 1860–1900, according to the instrumental temperature record. This measured temperature increase is not significantly affected by the urban heat island. Since 1979, land temperatures have increased about twice as fast as ocean temperatures (0.25 °C/decade against 0.13 °C/decade).[22] Temperatures in the lower troposphere have increased between 0.12 and 0.22 °C (0.22 and 0.4 °F) per decade since 1979, according to satellite temperature measurements. Temperature is believed to have been relatively stable over the one or two thousand years before 1850, with possibly regional fluctuations such as the Medieval Warm Period or the Little Ice Age.

Based on estimates by NASA's Goddard Institute for Space Studies, 2005 was the warmest year since reliable, widespread instrumental measurements became available in the late 1800s, exceeding the previous record set in 1998 by a few hundredths of a degree.[23] Estimates prepared by the World Meteorological Organization and the Climatic Research Unit concluded that 2005 was the second warmest year, behind 1998.[24][25]

Anthropogenic emissions of other pollutants—notably sulfate aerosols—can exert a cooling effect by increasing the reflection of incoming sunlight. This partially accounts for the cooling seen in the temperature record in the middle of the twentieth century,[26] though the cooling may also be due in part to natural variability.

Pre-industrial global warming

Two millennia of mean surface temperatures according to different reconstructions, each smoothed on a decadal scale. The unsmoothed, annual value for 2004 is also plotted for reference.

Paleoclimatologist William Ruddiman has argued that human influence on the global climate began around 8,000 years ago with the start of forest clearing to provide land for agriculture and 5,000 years ago with the start of Asian rice irrigation.[27] He contends that forest clearing explains the rise in CO2 levels in the current interglacial that started 8,000 years ago, contrasting with the decline in CO2 levels seen in the previous three interglacials. He further contends that the spread of rice irrigation explains the breakdown in the last 5,000 years of the correlation between the Northern Hemisphere solar radiation and global methane levels, which had been maintained over at least the last eleven 22,000-year cycles. Ruddiman argues that without these effects, the Earth would be nearly 2 °C (3.6 °F) cooler and "well on the way" to a new ice age. Ruddiman's interpretation of the historical record, with respect to the methane data, has been disputed.[28]

Pre-human global warming

Further information: Paleoclimatology
See also: Snowball Earth

The earth has experienced natural global warming and cooling many times in the past. The recent Antarctic EPICA ice core spans 800,000 years, including eight glacial cycles timed by orbital variations with interglacial warming periods about comparable to current temperatures.

A rapid buildup of greenhouse gases caused the Earth to experience global warming in the early Jurassic period, with average temperatures rising by 5 °C (9.0 °F). Research by the Open University indicates that this caused the rate of rock weathering to increase by 400%. As such weathering locks away carbon in calcite and dolomite, CO2 levels dropped back to normal over roughly the next 150,000 years.[29][30]

Sudden releases of methane from clathrate compounds (the clathrate gun hypothesis) have been hypothesized as a cause for other past global warming events, including the Permian-Triassic extinction event and the Paleocene-Eocene Thermal Maximum.

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.
File:Global Warming Predictions Map 2.jpg
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)

Scientists have studied global warming with computer models of the climate. These models are based on physical principles of fluid dynamics, radiative transfer, and other processes, with some simplifications being necessary because of limitations in computer power. These models predict that the net effect of adding greenhouse gases is to produce a warmer climate. However, even when the same assumptions of fossil fuel consumption and CO2 emission are used, the amount of predicted warming varies between models and there still remains a considerable range of climate sensitivity.

Including uncertainties in the models and in future greenhouse gas concentrations, the IPCC anticipates a warming of 1.1 °C to 6.4 °C (2.0 °F to 11.5 °F) between 1990 and 2100. Models have also been used to help investigate the causes of recent climate change by comparing the observed changes to those that the models predict from various natural and human derived causes.

Climate models can produce a good match to observations of global temperature changes over the last century.[31] These models do not unambiguously attribute the warming that occurred from approximately 1910 to 1945 to either natural variation or human effects; however, they suggest that the warming since 1975 is dominated by man-made greenhouse gas emissions.

Most global climate models, when run to predict future climate, are forced by imposed greenhouse gas scenarios, generally one from the IPCC Special Report on Emissions Scenarios (SRES). Less commonly, models may be run by adding a simulation of the carbon cycle; this generally shows a positive feedback, though this response is uncertain (under the A2 SRES scenario, responses vary between an extra 20 and 200 ppm of CO2). Some observational studies also show a positive feedback.[32]

The representation of clouds is one of the main sources of uncertainty in present-generation models, though progress is being made on this problem.[33] There is also an ongoing discussion as to whether climate models are neglecting important indirect and feedback effects of solar variability.

Attributed and expected effects

Main article: Effects of global warming
Global glacial mass balance in the last 50 years, reported to the WGMS and the NSIDC. The increased downward trend in the late 1980s is symptomatic of the increased rate and number of retreating glaciers.

Some effects on both the natural environment and human life are, at least in part, already being attributed to global warming. A 2001 report by the IPCC suggests that glacier retreat, ice shelf disruption such as the Larsen Ice Shelf, sea level rise, changes in rainfall patterns, increased intensity and frequency of extreme weather events, are being attributed in part to global warming.[34] While changes are expected for overall patterns, intensity, and frequencies, it is difficult to attribute specific events to global warming. Other expected effects include water scarcity, changes in mountain snowpack, adverse health effects from warmer temperatures, and the spread of disease.

Increasing extreme weather catastrophes are primarily due to an increase in population, and are partly due to increasing severe weather. The World Meteorological Organization said that scientific assessments indicate as global temperatures continue to warm, the number and intensity of extreme events might increase.[35] Hoyos et al. find that the increasing number of category 4 and 5 hurricanes is directly linked to increasing temperatures.[36] Kerry Emmanuel in Nature writes that hurricane power dissipation is highly correlated with temperature, reflecting global warming.[37] Thomas Knutson and Robert E. Tuleya of NOAA stated in 2004 that warming induced by greenhouse gas may lead to increasing occurrence of highly destructive category 5 storms.[38] A summary of probable effects and recent understanding can be found in the report of the IPCC Working Group II;[34] the newer AR4 summary reports, "There is observational evidence for an increase of intense tropical cyclone activity in the North Atlantic since about 1970, correlated with increases of tropical sea surface temperatures. There are also suggestions of increased intense tropical cyclone activity in some other regions where concerns over data quality are greater. Multi-decadal variability and the quality of the tropical cyclone records prior to routine satellite observations in about 1970 complicate the detection of long-term trends in tropical cyclone activity. There is no clear trend in the annual numbers of tropical cyclones."[1]

Additional anticipated effects include sea level rise of 110 to 770 mm (0.36 to 2.5 feet) by 2100,[39] repercussions to agriculture, possible slowing of the thermohaline circulation, reductions in the ozone layer, increased intensity and frequency of hurricanes and extreme weather events, lowering of ocean pH, and the spread of diseases such as malaria and dengue fever. One study predicts 18 to 35% of a sample of 1,103 animal and plant species would be extinct by 2050, based on future climate projections.[40] Mechanistic studies have documented extinctions due to recent climate change: McLaughlin et al. documented two populations of Bay checkerspot butterfly being threatened by precipitation change.[41] Parmesan states, "Few studies have been conducted at a scale that encompasses an entire species"[42] and McLaughlin et al. agree "few mechanistic studies have linked extinctions to recent climate change."[41]

Economics

Main article: Economics of global warming

Some economists have tried to estimate the aggregate net economic costs of damages from climate change across the globe (the social cost of carbon (SCC)). Such estimates have so far failed to reach conclusive findings; in a survey of 100 estimates, the values ran from US$-10 per tonne of carbon (tC) (US$-3 per tonne of carbon dioxide) up to US$350/tC (US$95 per tonne of carbon dioxide), with a mean of US$43 per tonne of carbon (US$12 per tonne of carbon dioxide).[43]

Mitigation, adaptation, and the Kyoto Protocol

Main articles: Mitigation of global warming, adaptation to global warming, and Kyoto Protocol

The broad agreement among climate scientists that global temperatures will continue to increase has led nations, states, corporations and individuals to implement actions to try to curtail global warming or adjust to it. Many environmental groups encourage individual action against global warming, often aimed at the consumer, and there has been business action on climate change. The world's primary international agreement on combating global warming is the Kyoto Protocol, an amendment to the United Nations Framework Convention on Climate Change (UNFCCC).

Controversy and politics

Main articles: Global warming controversy and Politics of global warming

The scientific findings surrounding global warming have led to the involvement of politicians, energy industry funding of critics and skeptical politicians, participation by environmental groups, and active discussions by pundit and media personalities over the cause, effects, and mitigations. Governments have taken stances, often widely divergent at national and local levels. U.S. officials, such as Philip Cooney, have repeatedly edited scientific reports from U.S. government scientists,[44] many of whom, such as Thomas Knutson, have been ordered to refrain from discussing climate change and related topics.[45][46][47] Fossil fuel companies have spent large sums of money for public relations to downplay its importance [1]. Environmental groups have launched far-reaching campaigns.

Related issues

Ocean acidification

Main article: Ocean acidification

Increased atmospheric CO2 increases the amount of CO2 dissolved in the oceans.[48] Carbon dioxide gas dissolved in the ocean reacts with water to form carbonic acid resulting in ocean acidification. Since biosystems are adapted to a narrow range of pH, this is a serious concern directly driven by increased atmospheric CO2.

Global dimming

Main article: Global dimming

Scientists have stated with 66-90% confidence that the effects of volcanic and human-caused aerosols have offset some of global warming, and that greenhouse gases would have resulted in more warming than observed if not for this effect.[1]

Ozone

Main article: Ozone depletion

Although global warming and ozone depletion often are linked in the media, the relationship between the two is not strong.

References

  1. ^ a b c d e f g "Climate Change 2007: The Physical Science Basis - Summary for Policymakers" (PDF). Intergovernmental Panel on Climate Change. 2007. Retrieved 2007-02-02.
  2. ^ American Quaternary Association (5 September 2006). "Petroleum Geologists' Award to Novelist Crichton Is Inappropriate" (pdf). Eos. 87 (3): 364. [AAPG] stands alone among scientific societies in its denial of human-induced effects on global warming.
  3. ^ "Climate Change Policy" (cfm). American Association of Petroleum Geologists. Retrieved 2007-03-30.
  4. ^ American Quaternary Association (5 September 2006). "Petroleum Geologists' Award to Novelist Crichton Is Inappropriate" (pdf). Eos. 87 (3): 364. Few credible scientists now doubt that humans have influenced the documented rise in global temperatures since the Industrial Revolution. {{cite journal}}: line feed character in |quote= at position 40 (help)
  5. ^ "Climate Change: Basic Information". U.S. Environmental Protection Agency. Retrieved 2007-02-09.
  6. ^ "United Nations Framework Convention on Climate Change, Article I". United Nations. Retrieved 2007-01-15.
  7. ^ "Joint science academies' statement: The science of climate change". Royal Society. May 17 2001. Retrieved 2007-04-01. The work of the Intergovernmental Panel on Climate Change (IPCC) represents the consensus of the international scientific community on climate change science {{cite web}}: Check date values in: |date= (help)
  8. ^ "Joint science academies' statement: Global response to climate change". Royal Society. 2005. Retrieved 2007-04-01. We recognise the international scientific consensus of the Intergovernmental Panel on Climate Change (IPCC) {{cite web}}: Unknown parameter |month= ignored (help)
  9. ^ "Living with Climate Change - An Overview of Potential Climate Change Impacts on Australia" (PDF). Australian Greenhouse Office. December 2002. Retrieved 2007-04-18. {{cite journal}}: Cite journal requires |journal= (help)
  10. ^ Climate Change 2001: Working Group I: The Scientific Basis, 7.5.2 Sea Ice, 2001. Retrieved on February 11 2007.
  11. ^ Gerald A. Meehl, et.al., "How Much More Global Warming and Sea Level Rise?" Science Magazine, 18 March 2005. Retrieved February 11, 2007.
  12. ^ Pearson, PN (2000). "Atmospheric carbon dioxide concentrations over the past 60 million years". Nature. 406 (6797): 695. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  13. ^ "Climate Change 2001: Working Group I: The Scientific Basis, Part 6". Intergovernmental Panel on Climate Change. 2001]. Retrieved 2007-01-18. {{cite web}}: Check date values in: |year= (help)
  14. ^ Climate Change 2001: Working Group I: The Scientific Basis, 3.7.3.3 SRES scenarios and their implications for future CO2 concentration
  15. ^ IPCC Special Report on Emissions Scenarios - 4.4.6. Resource Availability
  16. ^ Sample, Ian (2005-08-11). "Warming Hits 'Tipping Point'". The Guardian. Retrieved 2007-01-18. {{cite news}}: Check date values in: |date= (help)
  17. ^ "Climate Change 2007: The Physical Science Basis - Summary for Policymakers" (PDF). Intergovernmental Panel on Climate Change. 2007. Retrieved 2007-03-30. Models used to date do not include uncertainties in climate-carbon cycle feedback nor do they include the full effects of changes in ice sheet flow {{cite journal}}: Cite journal requires |journal= (help)}
  18. ^ Marsh, Nigel; Svensmark, Henrik (2000), "Cosmic Rays, Clouds, and Climate" (PDF), Space Science Reviews, 94 (1–2): 215–230, doi:10.1023/A:1026723423896, retrieved 2007-04-17
  19. ^ Haigh, Joanna D. (2003-01-15). "The effects of solar variability on the Earth's climate". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 361 (1802): 91–111. doi:10.1098/rsta.2002.1111. Retrieved 2007-03-15. {{cite journal}}: Check date values in: |date= (help)
  20. ^ Scafetta, Nicola (2005). "Estimated solar contribution to the global surface warming using the ACRIM TSI satellite composite" (PDF). Geophysical Research Letters. 32. doi:10.1029/2005GL023849. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  21. ^ Stott, Peter A.; Jones, Gareth S.; Mitchell, John F. B. (2003), "Do Models Underestimate the Solar Contribution to Recent Climate Change?" (PDF), Journal of Climate, 16 (24): 4079–4093, doi:10.1175/1520-0442(2003)016%3C4079:DMUTSC%3E2.0.CO;2, retrieved 2007-04-16
  22. ^ Smith, Thomas M. (2005-05-15). "A Global Merged Land–Air–Sea Surface Temperature Reconstruction Based on Historical Observations (1880–1997)" (PDF). Journal of climate. 18 (12). American Meteorological Society: 2021–2036. ISSN 0894-8755. Retrieved 2007-03-14. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  23. ^ "Goddard Institute for Space Studies, GISS Surface Temperature Analysis". NASA Goddard Institute for Space Studies. 2006-01-12. Retrieved 2007-01-17. {{cite web}}: Check date values in: |date= (help)
  24. ^ "The December Press Release 2005" (Word). Climactic Research Unit, School of Environmental Sciences, University of East Anglia. 2005-12-15. Retrieved 2007-04-13. {{cite web}}: Check date values in: |date= (help)
  25. ^ "WMO STATEMENT ON THE STATUS OF THE GLOBAL CLIMATE IN 2005". World Meteorological Organization. 2005-12-15. Retrieved 2007-04-13. {{cite web}}: Check date values in: |date= (help)
  26. ^ "Climate Change 2001: Working Group I: The Scientific Basis, Chapter 12.4.3.3". Intergovernmental Panel on Climate Change. 2001. Retrieved 2007-01-04. {{cite web}}: Check date values in: |year= (help)
  27. ^ William Ruddiman (March 2005). "How Did Humans First Alter Global Climate?" (PDF). March 2005 issue. Scientific American. Retrieved 2007-03-05. {{cite journal}}: Cite journal requires |journal= (help)
  28. ^ Schmidt, Gavin (2004). "A note on the relationship between ice core methane concentrations and insolation". Geophysical Research Letters. 31. doi:10.1029/2004GL021083. ISSN 0094-8276. L23206. Retrieved 2007-03-05. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  29. ^ "The Open University Provides Answers on Global Warming" (PDF) (Press release). The Open University. January 30, 2004. Retrieved 2007-03-04.
  30. ^ Cohen, Anthony S. (2004). "Osmium isotope evidence for the regulation of atmospheric CO2 by continental weathering" (HTML/PDF). Geology. 32 (2): 157–160. doi:0.1130/G20158.1. Retrieved 2007-03-04. {{cite journal}}: Check |doi= value (help); Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  31. ^ "Climate Change 2001: Working Group I: The Scientific Basis". Intergovernmental Panel on Climate Change Work Group I. 2001. pp. Based upon Chapter 12, Figure 12.7. Retrieved 2007-03-04.
  32. ^ Torn, Margaret (2006-05-26). "Missing feedbacks, asymmetric uncertainties, and the underestimation of future warming". Geophysical Research Letters. 33 (10). L10703. Retrieved 2007-03-04. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  33. ^ "Climate Change 2001: Working Group I: The Scientific Basis". Intergovernmental Panel on Climate Change Work Group I. 2001. pp. Chapter 7.2.2. Retrieved 2007-03-04.
  34. ^ a b "Climate Change 2001: Working Group II: Impacts, Adaptation and Vulnerability". Retrieved 2007-03-14.
  35. ^ The Independent/UK, Extreme Weather Prompts Unprecedented Global Warming Alert, July 3, 2003. Retrieved on March 4 2007.
  36. ^ Hoyos et al., Science (journal), Deconvolution of the Factors Contributing to the Increase in Global Hurricane Intensity, March 7, 2006. Retrieved on March 4 2007.
  37. ^ Emmanuel, K. (August 2005) "Increasing destructiveness of tropical cyclones over the past 30 years" (PDF). Nature 436: 686-688.
  38. ^ Thomas R. Knutson, et. al., Journal of Climate, Impact of CO2-Induced Warming on Simulated Hurricane Intensity and Precipitation: Sensitivity to the Choice of Climate Model and Convective Parameterization (PDF), 15 September 2004. Retrieved on March 4 2007.
  39. ^ "Climate Change 2001: The Scientific Basis". Retrieved 2005-12-19.
  40. ^ Thomas, Chris D. (2004-01-08). "Extinction risk from climate change" (PDF). Nature. 427: 145–138. doi:10.1038/nature02121. Retrieved 2007-03-18. {{cite journal}}: Check date values in: |date= (help); Italic or bold markup not allowed in: |journal= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  41. ^ a b McLaughlin, John F. (2002-04-30). "Climate change hastens population extinctions" (PDF). PNAS. 99 (9): 6070–6074. doi:10.1073/pnas.052131199. Retrieved 2007-03-29. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  42. ^ Permesan, Camille (2006-08-24). "Ecological and Evolutionary Responses to Recent Climate Change" (PDF). Annual Review of Ecology, Evolution, and Systematics. 37: 637–669. doi:10.1146/annurev.ecolsys.37.091305.110100. Retrieved 2007-03-30. {{cite journal}}: Check date values in: |date= (help)
  43. ^ 2007 IPCC Summary for Policymakers
  44. ^ Campbell, D. (June 20, 2003) "White House cuts global warming from report" Guardian Unlimited
  45. ^ Donaghy, T., et al. (2007) "Atmosphere of Pressure:" a report of the Government Accountability Project (Cambridge, Mass.: UCS Publications)
  46. ^ Rule, E. (2005) "Possible media attention" Email to NOAA staff, July 27. Obtained via FOIA request on July 31, 2006. and Teet, J. (2005) "DOC Interview Policy" Email to NOAA staff, September 29. Originally published by Alexandrovna, L. (2005) "Commerce Department tells National Weather Service media contacts must be pre-approved" The Raw Story, October 4. Accessed December 22, 2006
  47. ^ Zabarenko, D. (2007) "'Don't discuss polar bears:' memo to scientists" Reuters
  48. ^ "The Ocean and the Carbon Cycle". NASA Oceanography (science@nasa). 2005-06-21. Retrieved 2007-03-04. {{cite web}}: External link in |work= (help)

Further reading

See also


External links

Scientific

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