Climate Change 2007, the Fourth Assessment Report (AR4) of the United Nations Intergovernmental Panel on Climate Change (IPCC), is the fourth in a series of such reports. The IPCC was established by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess scientific, technical and socio-economic information concerning climate change, its potential effects and options for adaptation and mitigation. Skeptics have made a variety of criticisms against the report. IPCC is the science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), to evaluate the risk of climate change brought on by humans, based mainly on... The Intergovernmental Panel on Climate Change first assessment report was completed in 1990, and served as the basis of the United Nations Framework Convention on Climate Change (UNFCCC). ... The Intergovernmental Panel on Climate Change supplementary report of 1992 was published to contribute to the debate on the United Nations Framework Convention on Climate Change at the 1992 Earth Summit, held in Rio de Janeiro. ... The Second Assessment Report (SAR) of the Intergovernmental Panel on Climate Change was published in 1995. ... The Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) was issued in 2001. ... UNFCCC logo. ... WMO flag The World Meteorological Organization (WMO, French: , OMM) is an intergovernmental organization with a membership of 188 Member States and Territories. ... Klaus Töpfer, former UNEP Exec. ... UN and U.N. redirect here. ... IPCC is the science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), to evaluate the risk of climate change brought on by humans, based mainly on... WMO flag The World Meteorological Organization (WMO, French: , OMM) is an intergovernmental organization with a membership of 188 Member States and Territories. ... Klaus Töpfer, former UNEP Exec. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 450,000 years For current global climate change, see Global warming. ... The IPCC Fourth Assessment Report (AR4) has been subjected to both scientific and non scientific (process based) criticism. ...

Climate Change 2007: Report Overview

The Fourth Assessment Report (Climate Change 2007)^[1] is released in four distinct sections:

• Working Group I Report (WGI): Climate Change 2007: The Physical Science Basis.
• Working Group II Report (WGII): Climate Change 2007: Impacts, Adaptation and Vulnerability.
• Working Group III Report (WGIII): Climate Change 2007: Mitigation of Climate Change (final version).
• The Synthesis Report (SYR): Summary for Policymakers (SPM)PDF (6.4 MiB) (pre-copy edit version).

For each section, the IPCC will release the main report and a summary version, known as the Summary for Policymakers. Full reports and summaries of Working Groups I-III have been released, plus a summary of the Synthesis Report. “PDF” redirects here. ... MiB redirects here. ...

Working Group I (WGI): The Physical Science Basis

The Working Group I Summary for Policymakers (SPM)^[2] was published on 2 February 2007 and revised on 5 February 2007. The full WGI report^[3] was published in March, and last updated on 5 September 2007. A 34-page Frequently Asked Questions document^[4] has been made available. is the 33rd day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 36th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ...

Climate Change 2007: The Physical Science Basis, the report of Working Group I, "assesses the current scientific knowledge of the natural and human drivers of climate change, observed changes in climate, the ability of science to attribute changes to different causes, and projections for future climate change".

The report was produced by around 600 authors from 40 countries, and reviewed by over 620 experts and governments. Before being accepted, the summary was reviewed line-by-line by representatives from 113 governments during the 10th Session of Working Group I,^[5] which took place in Paris, France, between 29 January and 1 February 2007. This article is about the capital of France. ... is the 29th day of the year in the Gregorian calendar. ... is the 32nd day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ...

On the issue of global warming and its causes, the SPM states that:^[2]

• "Warming of the climate system is unequivocal."
• "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."

Footnotes on page 4 of the summary indicate very likely and likely mean "the assessed likelihood, using expert judgment", are over 90% and 66% respectively. Look up anthropogenic in Wiktionary, the free dictionary. ...

Observations

The report notes many observed changes in the Earth's climate including atmospheric composition, global average temperatures, ocean conditions, and other climate changes.

Changes in the atmosphere

Carbon dioxide, methane, and nitrous oxide are all long-lived greenhouse gases. Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... Methane is a chemical compound with the molecular formula . ... For other uses, see Nitrous oxide (disambiguation). ... Greenhouse gases are gaseous components of the atmosphere that contribute to the greenhouse effect. ...

• "Carbon dioxide, methane, and nitrous oxide have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values."
• The amount of carbon dioxide in the atmosphere in 2005 (379 ppm) exceeds by far the natural range of the last 650,000 years (180 to 300 ppm).
• The amount of methane in the atmosphere in 2005 (1774 ppb) exceeds by far the natural range of the last 650,000 years (320 to 790 ppb).
• The primary source of the increase in carbon dioxide is fossil fuel use, but land-use changes also make a contribution.
• The primary source of the increase in methane is very likely to be a combination of human agricultural activities and fossil fuel use. How much each contributes is not well determined.
• Nitrous oxide concentrations have risen from a pre-industrial value of 270 ppb to a 2005 value of 319 ppb. More than a third of this rise is due to human activity, primarily agriculture.

Parts-per notation is a measure of concentration that is used where low levels of concentration are significant. ... Parts-per notation is a measure of concentration that is used where low levels of concentration are significant. ... Fossil fuels or mineral fuels are fossil source fuels, this is, hydrocarbons found within the top layer of the earth’s crust. ... Agriculture is the production of food, feed, fiber and other goods by the systematic raising of domesticated plants and animals. ...

Warming of the planet

Cold days, cold nights, and frost events have become less frequent. Hot days, hot nights, and heat waves have become more frequent. Additionally:

• Eleven of the twelve years in the period (1995-2006) rank among the top 12 warmest years in the instrumental record (since 1850, towards the end of the Little Ice Age).
• Warming in the last 100 years has caused about a 0.74 °C increase in global average temperature. This is up from the 0.6 °C increase in the 100 years prior to the Third Assessment Report.
• Urban heat island effects were determined to have negligible influence (less than 0.0006 °C per decade over land and zero over oceans) on these measurements.
• Observations since 1961 show that the ocean has been absorbing more than 80% of the heat added to the climate system, and that ocean temperatures have increased to depths of at least 3000 m (9800 ft).
• "Average Arctic temperatures increased at almost twice the global average rate in the past 100 years."
• It is likely that greenhouse gases would have caused more warming than we have observed if not for the cooling effects of volcanic and human-caused aerosols. See global dimming.
• Average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than during any other 50-year period in the last 500 years and likely the highest in at least the past 1300 years (a time near the beginning of the Little Ice Age).

Tokyo, a case of Urban Heat Island. ... Global dimming is the gradual reduction in the amount of global direct irradiance at the Earths surface that was observed for several decades after the start of systematic measurements in 1950s. ...

Ice, snow, permafrost, rain, and the oceans

The SPM documents increases in wind intensity, decline of permafrost coverage, and increases of both drought and heavy precipitation events. Additionally:

• "Mountain glaciers and snow cover have declined on average in both hemispheres."
• Losses from the land-based ice sheets of Greenland and Antarctica have very likely (>90%) contributed to sea level rise between 1993 and 2003.
• Ocean warming causes seawater to expand, which contributes to sea level rising.
• Sea level rose at an average rate of about 1.8 mm/year during the years 1961-2003. The rise in sea level during 1993-2003 was at an average rate of 3.1 mm/year. It is not clear whether this is a long-term trend or just variability.
• Antarctic sea ice shows no significant overall trend, consistent with a lack of warming in that region.

This article is about the geological formation. ... An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 square kilometers (12 million acres). ... An icebreaker navigates through young (1 year old) sea ice Nilas Sea Ice in arctic Sea ice is formed from ocean water that freezes. ...

Hurricanes

• There has been an increase in hurricane intensity in the North Atlantic since the 1970s, and that increase correlates with increases in sea surface temperature.
• The observed increase in hurricane intensity is larger than climate models predict for the sea surface temperature changes we have experienced.
• There is no clear trend in the number of hurricanes.
• Other regions appear to have experienced increased hurricane intensity as well, but there are concerns about the quality of data in these other regions.
• It is more likely than not (>50%) that there has been some human contribution to the increases in hurricane intensity.
• It is likely (>66%) that we will see increases in hurricane intensity during the 21st century.

Table SPM-2 lists recent trends along with certainty levels for the trend having actually occurred, for a human contribution to the trend, and for the trend occurring in the future. In relation to changes (including increased hurricane intensity) where the certainty of a human contribution is stated as "more likely than not" footnote f to table SPM-2 notes "Magnitude of anthropogenic contributions not assessed. Attribution for these phenomena based on expert judgment rather than formal attribution studies." Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004 Hurricane and Typhoon redirect here. ... For other uses, see Atlantic (disambiguation) The Atlantic Ocean is Earths second-largest ocean, covering approximately one-fifth of its surface. ... Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface, and ice. ...

Factors that warm or cool the planet

Changes in radiative forcings between 1750 and 2005 as estimated by the IPCC.

AR4 describes warming and cooling effects on the planet in terms of radiative forcing — the rate of change of energy in the system, measured as power per unit area (in SI units, W/m²). The report shows in detail the individual warming contributions (positive forcing) of carbon dioxide, methane, nitrous oxide, halocarbons, other human warming factors, and the warming effects of changes in solar activity. Also shown are the cooling effects (negative forcing) of aerosols, land-use changes, and other human activities. All values are shown as a change from pre-industrial conditions. Image File history File links Radiative-forcings. ... Image File history File links Radiative-forcings. ... The generalised concept of radiative forcing in climate science is any change in the radiation (heat) entering the climate system or changes in radiatively active gases. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... The generalised concept of radiative forcing in climate science is any change in the radiation (heat) entering the climate system or changes in radiatively active gases. ... In organic chemistry, a halocarbon is a compound containing carbon and one or more halogens. ... Particulates, alternatively referred to as particulate matter (PM), aerosols or fine particles, are tiny particles of solid or liquid suspended in a gas. ... Land cover is the physical material at the surface of the earth. ...

• Total radiative forcing from the sum of all human activities is a warming force of about +1.6 watts/m²
• Radiative forcing from an increase of solar intensity since 1750 is about +0.12 watts/m²
• Radiative forcing from carbon dioxide, methane, and nitrous oxide combined is very likely (>90%) increasing more quickly during the current era (1750-present) than at any other time in the last 10,000 years.

Solar irradiance spectrum at top of atmosphere. ...

Climate sensitivity

Climate sensitivity is defined as the amount of global average surface warming following a doubling of carbon dioxide concentrations. It is likely to be in the range of 2 to 4.5 °C, with a best estimate of about 3 °C. This range of values is not a projection of the temperature rise we will see in the 21st century, since the future change in carbon dioxide concentrations is unknown, and factors besides carbon dioxide concentrations affect temperature. In IPCC reports, equilibrium climate sensitivity refers to the equilibrium change in global mean surface temperature following a doubling of the atmospheric (equivalent) CO2 concentration. ...

Model-based projections for the future

The projected temperature increase for a range of stabilization scenarios (the coloured bands). The black line in middle of the shaded area indicates 'best estimates'; the red and the blue lines the likely limits. From the work of Working Group III.

Model projections are made based on an analysis of various computer climate models running within different SRES scenarios. As a result, predictions for the 21st century are as shown below. Image File history File links Size of this preview: 800 × 409 pixelsFull resolution (1431 × 731 pixel, file size: 122 KB, MIME type: image/png) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Size of this preview: 800 × 409 pixelsFull resolution (1431 × 731 pixel, file size: 122 KB, MIME type: image/png) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Global warming refers to the increase in the average temperature of the Earths near-surface air and oceans in recent decades and its projected continuation. ... Climate Change 2007, the Fourth Assessment Report (AR4) of the United Nations Intergovernmental Panel on Climate Change (IPCC), is the fourth in a series of such reports. ... The Special Report on Emissions Scenarios was a report, prepared for the IPCC TAR, on future emission scenarios to be used for driving global circulation models to develop climate change scenarios. ...

• Surface air warming in the 21st century:
  • Best estimate for a "low scenario"^[6] is 1.8 °C with a likely range of 1.1 to 2.9 °C (3.2 °F with a likely range of 2.0 to 5.2 °F)
  • Best estimate for a "high scenario"^[7] is 4.0 °C with a likely range of 2.4 to 6.4 °C (7.2 °F with a likely range of 4.3 to 11.5 °F)
  • A temperature rise of about 0.1 °C per decade would be expected for the next two decades, even if greenhouse gas and aerosol concentrations were kept at year 2000 levels.
  • A temperature rise of about 0.2 °C per decade is projected for the next two decades for all SRES scenarios.
  • Confidence in these near-term projections is strengthened because of the agreement between past model projections and actual observed temperature increases.
• Based on multiple models that all exclude ice sheet flow due to a lack of basis in published literature,^[8] it is estimated that sea level rise will be:
  • in a low scenario^[6] 18 to 38 cm (7 to 15 inches)
  • in a high scenario^[7] 26 to 59 cm (10 to 23 inches)
• It is very likely that there will be an increase in frequency of warm spells, heat waves and events of heavy rainfall.
• It is likely that there will be an increase in areas affected by droughts, intensity of tropical cyclones (which include hurricanes and typhoons) and the occurrence of extreme high tides.
• "Sea ice is projected to shrink in both the Arctic and Antarctic … In some projections, Arctic late-summer sea ice disappears almost entirely by the latter part of the 21st century."

Scenario-specific projections are based on analysis of multiple runs by multiple climate models, using the various SRES Scenarios. "Low scenario" refers to B1, the most optimistic scenario family. "High scenario" refers to A1FI, the most pessimistic scenario family. An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² (19,305 mile²).[1] The only current ice sheets are in Antarctica and Greenland; during the last ice age at Last Glacial Maximum (LGM) the Laurentide ice sheet covered much... Sea level measurements from 23 long tide gauge records in geologically stable environments show a rise of around 20 centimeters per century (2 mm/year). ... For other uses, see Heat wave (disambiguation). ... Fields outside Benambra, Victoria, Australia suffering from drought conditions A drought is an extended period of months or years when a region notes a deficiency in its water supply. ... Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004 Hurricane and Typhoon redirect here. ... Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004. ... High Tide was a band that was formed in 1969 by Tony Hill (guitar, keyboards, and vocals), Simon House (violin and keyboards), Pete Pavli (bass) and Roger Hadden (drums). ... NOAA Projected arctic changes Polar ice packs are large areas of pack ice formed from seawater in the Earths polar regions, known as polar ice caps: the Arctic ice pack (or Arctic ice cap) of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean, fringing the... The Special Report on Emissions Scenarios was a report, prepared for the IPCC TAR, on future emission scenarios to be used for driving global circulation models to develop climate change scenarios. ...

Temperature and sea level rise for each SRES scenario family

There are six families of SRES Scenarios, and AR4 provides projected temperature and sea level rises for each scenario family. The Special Report on Emissions Scenarios was a report, prepared for the IPCC TAR, on future emission scenarios to be used for driving global circulation models to develop climate change scenarios. ...

• Scenario B1
  • Best estimate temperature rise of 1.8 °C with a likely range of 1.1 to 2.9 °C (3.2 °F with a likely range of 2.0 to 5.2 °F)
  • Sea level rise likely range [18 to 38 cm] (7 to 15 inches)
• Scenario A1T
  • Best estimate temperature rise of 2.4 °C with a likely range of 1.4 to 3.8 °C (4.3 °F with a likely range of 2.5 to 6.8 °F)
  • Sea level rise likely range [20 to 45 cm] (8 to 18 inches)
• Scenario B2
  • Best estimate temperature rise of 2.4 °C with a likely range of 1.4 to 3.8 °C (4.3 °F with a likely range of 2.5 to 6.8 °F)
  • Sea level rise likely range [20 to 43 cm] (8 to 17 inches)
• Scenario A1B
  • Best estimate temperature rise of 2.8 °C with a likely range of 1.7 to 4.4 °C (5.0 °F with a likely range of 3.1 to 7.9 °F)
  • Sea level rise likely range [21 to 48 cm] (8 to 19 inches)
• Scenario A2
  • Best estimate temperature rise of 3.4 °C with a likely range of 2.0 to 5.4 °C (6.1 °F with a likely range of 3.6 to 9.7 °F)
  • Sea level rise likely range [23 to 51 cm] (9 to 20 inches)
• Scenario A1FI
  • Best estimate temperature rise of 4.0 °C with a likely range of 2.4 to 6.4 °C (7.2 °F with a likely range of 4.3 to 11.5 °F)
  • Sea level rise likely range [26 to 59 cm] (10 to 23 inches)

Selected quotes from the WGI Summary for Policymakers

• "Both past and future anthropogenic carbon dioxide emissions will continue to contribute to warming and sea level rise for more than a millennium, due to the timescales required for removal of this gas from the atmosphere."

Reaction to WGI

In the weeks before publication of the first report, controversy broke out about the report's projections of sea-level change, which in the new report was estimated at less than previous estimates. The now-published text gives a warning that the new estimation of sea-level could be too low: "Dynamical processes related to ice flow not included in current models but suggested by recent observations could increase the vulnerability of the ice sheets to warming, increasing future sea level rise." The mid-points of the sea level rise estimates are within ±10% of those from the TAR; but the range has narrowed. Tar can be produced from corn stalks by heating in a microwave. ...

Lord Rees, the president of the Royal Society, said, "This report makes it clear, more convincingly than ever before, that human actions are writ large on the changes we are seeing, and will see, to our climate. The IPCC strongly emphasises that substantial climate change is inevitable, and we will have to adapt to this. This should compel all of us - world leaders, businesses and individuals - towards action rather than the paralysis of fear. We need both to reduce our emissions of greenhouse gases and to prepare for the impacts of climate change. Those who would claim otherwise can no longer use science as a basis for their argument."^[9] Professor Martin Rees Martin John Rees, Baron Rees of Ludlow, FRS (born 23 June 1942) is a professor of astronomy. ... For other uses, see Royal Society (disambiguation). ...

U.S. Energy Secretary Samuel Bodman told a news conference that the report was "sound science" and "As the president has said, and this report makes clear, human activity is contributing to changes in our earth's climate and that issue is no longer up for debate."^[10] Kurt Volker, Principal Deputy Assistant Secretary for European and Eurasian Affairs, said, "We support the recent IPCC report, in which U.S. scientists played a leading role."^[11]

Based on the report, 46 countries in a "Paris Call for Action" read out by French President Chirac, have called for the creation of a United Nations Environment Organization (UNEO), which is to have more power than the current United Nations Environment Programme (UNEP), and is to be modelled after the more powerful World Health Organization. The 46 countries included the European Union nations, but notably did not include the United States, China, Russia, and India, the top four emitters of greenhouse gases.^[12] Jacques (René) Chirac (born 29 November French politician. ... Klaus Töpfer, former UNEP Exec. ... WHO redirects here. ...

Working Group II (WGII): Impacts, Adaptation and Vulnerability

The summary for policymakers for the Working Group II^[13] report was released on April 6, 2007.^[14] The full report^[15] was released September 18, 2007. is the 96th day of the year (97th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ...

WGII states that "evidence from all continents and most oceans shows that many natural systems are being affected by regional climate changes, particularly temperature increases."

Observations

Some observed changes have been associated with climate change at varying levels of confidence.

With a High Confidence (about an 8 in 10 chance to be correct) WGII asserts that climate change has resulted in:

• More and larger glacial lakes.
• Increasing ground instability in permafrost regions.
• Increasing rock avalanches in mountain regions.
• Changes in some Arctic and Antarctic ecosystems.
• Increased run-off and earlier spring peak discharge in many glacier and snow-fed rivers.
• Changes affecting algae, plankton, fish and zooplankton because rising water temperatures and changes in:
  • ice cover
  • salinity
  • oxygen levels
  • water circulation

With a Very High Confidence (about a 9 in 10 chance to be correct) WGII asserts that climate change is affecting terrestrial biological systems in that:

• Spring events such as the unfolding of leaves, laying of eggs, and migration are happening earlier.
• There are poleward and upward (to higher altitude) shifts in ranges of plant and animal species.

WGII also states that the ocean has become more acidic because it has absorbed human-caused carbon dioxide. Ocean pH has dropped by 0.1, but how this affects marine life is not documented.

Attribution of Changes

WGII acknowledges some of the difficulties of attributing specific changes to human-caused global warming, stating that "Limitations and gaps prevent more complete attribution of the causes of observed system responses to anthropogenic warming." but found that the agreement between observed and projected changes was "Nevertheless ... sufficient to conclude with high confidence that anthropogenic warming over the last three decades has had a discernible influence on many physical and biological systems."

Projections

WGII describes some of what might be expected in the coming century, based on studies and model projections.

Fresh Water

It is projected with High Confidence that:

• Dry regions are projected to get drier, and wet regions are projected to get wetter: "By mid-century, annual average river runoff and water availability are projected to increase by 10-40% at high latitudes and in some wet tropical areas, and decrease by 10-30% over some dry regions at mid-latitudes and in the dry tropics..."
• Drought-affected areas will become larger.
• Heavy precipitation events are very likely to become more common and will increase flood risk.
• Water supplies stored in glaciers and snow cover will be reduced over the course of the century.

Ecosystems

It is projected with High Confidence that:

• The resilience of many ecosystems is likely to be exceeded this century by a combination of climate change and other stressors.
• Carbon removal by terrestrial ecosystems is likely to peak before mid-century and then weaken or reverse. This would amplify climate change.

For the band, see Resilience (band). ...

Food

It is projected with Medium Confidence (about 5 in 10 chance to be correct) that globally, potential food production will increase for temperature rises of 1-3 °C, but decrease for higher temperature ranges. Fortunately, temperatures are not expected to rise to these ranges in the near future.

Coastal Systems

It is projected with Very High Confidence that:

• Coasts will be exposed to increasing risks such as coastal erosion due to climate change and sea-level rise.
• "Increases in sea-surface temperature of about 1-3 °C are projected to result in more frequent coral bleaching events and widespread mortality unless there is thermal adaptation or acclimatisation by corals."
• "Many millions more people are projected to be flooded every year due to sea-level rise by the 2080s."

Objections to original WGII language

U.S. negotiators managed to eliminate language calling for cuts in greenhouse gas emissions, according to Patricia Romero Lankao, a lead author from the National Center for Atmospheric Research (NCAR). The original draft read: "However, adaptation alone is not expected to cope with all the projected effects of climate change, and especially not over the long run as most impacts increase in magnitude. Mitigation measures will therefore also be required." The second sentence does not appear in the final version of the report.^[16] NCAR, Boulder, Colorado National Center for Atmospheric Research (NCAR) is a U.S.-based institute whose stated mission is: NCARs flagship Mesa Laboratory is located in the outskirts of Boulder, Colorado, in a dramatic complex of buildings designed by architect I.M. Pei. ...

China objected to wording that said "based on observed evidence, there is very high confidence that many natural systems, on all continents and in most oceans, are being affected by regional climate changes, particularly temperature increases." When China asked that the word "very" be stricken, three scientific authors balked, and the deadlock was broken only by a compromise to delete any reference to confidence levels.^[16]

Working Group III (WGIII): Mitigation of Climate Change

See also: Mitigation of global warming

The Working Group III^[17] Summary for Policymakers (SPM)^[18] was published on 4 May 2007 at the 26th session of the IPCC.^[19] The full WG III report was published online in September, 2007.^[20] Global carbon dioxide emissions 1800–2000 Global average surface temperature 1850 to 2006 Mitigation of global warming involves taking actions aimed at reducing the extent of global warming. ... is the 124th day of the year (125th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ...

The IPCC convened in Bangkok on April 30 to start discussions on the draft Summary, with the participation of over 400 scientists and experts from about 120 countries.^[21] At the full IPCC meeting on May 4, agreement was reached by the larger gathering of some 2,000 delegates. One of the key debates concerned a proposal to limit concentrations of greenhouse gases in the atmosphere to between 445 parts per million and 650 parts per million to avoid dangerous climate change, with pressure from developing countries to raise the lower limit. Despite this, the figures from the original proposal were incorporated into the Summary for Policymakers.^[22] The Summary concludes that stabilization of greenhouse gas concentrations is possible at a reasonable cost, with stabilization between 445ppm and 535ppm costing less than 3% of global GDP.^[23] Location within in Thailand Coordinates: , Country Settled Ayutthaya Period Founded as capital 21 April 1782 Government  - Type Special administrative area  - Governer Apirak Kosayothin Area  - City 1,568. ... Global carbon dioxide emissions 1800–2000 Global average surface temperature 1850 to 2006 Avoiding Dangerous Climate Change: A Scientific Symposium on Stabilisation of Greenhouse Gases was a 2005 international conference that redefined the link between atmospheric greenhouse gas concentration, and the 2°C (3. ...

The WG III report analyses mitigation options for the main sectors in the near-term, addressing also cross-sectorial matters such as synergies, co-benefits, and trade-offs. It also provides information on long-term mitigation strategies for various stabilization levels, paying special attention to implications of different short-term strategies for achieving long-term goals. ^[24]

Mitigation in the short and medium term (until 2030)

The Summary for Policymakers concludes that there was a high level of agreement and much evidence that 'there is substantial economic potential for the mitigation of global greenhouse gas emissions over the coming decades, that could offset the projected growth of global emissions or reduce emissions below current levels',^[25] taking into account financial and social costs and benefits.^[26] The technologies with the largest economic potential within this timescale are considered to be:^[27] Top: Increasing atmospheric CO2 levels as measured in the atmosphere and ice cores. ...

The IPCC estimates that stabilizing atmospheric greenhouse gases at between 445-535ppm CO₂ equivalent would result in a reduction of average annual GDP growth rates of less than 0.12%. stabilizing at 535 to 590ppm would reduce average annual GDP growth rates by 0.1%, while stabilization at 590 to 710ppm would reduce rates by 0.06%.^[28] There was high agreement and much evidence that a substantial fraction of these mitigation costs may be offset by benefits to health as a result of reduced air pollution, and that there would be further cost savings from other benefits such as increased energy security, increased agricultural production, and reduced pressure on natural ecosystems as well as, in certain countries, balance of trade improvements, provision of modern energy services to rural areas and employment.^[29] Energy supply is the delivery of fuels or transformed fuels to point of consumption. ... Coal Example chemical structure of coal Coal (pronounced ) is a fossil fuel formed in swamp ecosystems where plant remains were saved by water and mud from oxidization and biodegradation. ... For other uses, see Natural gas (disambiguation). ... This article is about applications of nuclear fission reactors as power sources. ... Renewable energy effectively utilizes natural resources such as sunlight, wind, tides and geothermal heat, which are naturally replenished. ... Undershot water wheels on the Orontes River in Hama, Syria Saint Anthony Falls Hydropower is the capture of the energy of moving water for some useful purpose. ... Solar power describes a number of methods of harnessing energy from the light of the sun. ... An example of a wind turbine. ... Krafla Geothermal Station in northeast Iceland Geothermal power (from the Greek words geo, meaning earth, and therme, meaning heat) is energy generated by heat stored beneath the Earths surface. ... For articles on specific fuels used in vehicles, see Biogas, Bioethanol, Biobutanol, Biodiesel, and Straight vegetable oil. ... Not to be confused with California Highway Patrol. ... Carbon capture and storage (CCS) is an approach to mitigating global warming by capturing carbon dioxide (CO2) from large point sources such as power plants and subsequently storing it instead of releasing it into the atmosphere. ... Tidal power, sometimes called tidal energy, is a form of hydropower that exploits the movement of water caused by tidal currents or the rise and fall in sea levels due to the tides. ... Wave power refers to the energy of ocean surface waves and the capture of that energy to do useful work - including electricity generation, desalination, and the pumping of water (into reservoirs). ... At the equator, the Sun provides approximately 1000 watts per square meter on Earths surface. ... Photovoltaic tree in Styria, Austria Photovoltaics, or PV for short, is a solar power technology that uses solar cells or solar photovoltaic arrays to convert light from the sun directly into electricity. ... For other types of Hybrid Transportation, see Hybrid (disambiguation)#Transportation. ... For articles on specific fuels used in vehicles, see Biogas, Bioethanol, Biobutanol, Biodiesel, and Straight vegetable oil. ... Disruptions in organized traffic flow can create delays lasting hours. ... This is the top-level page of WikiProject trains Rail tracks Rail transport refers to the land transport of passengers and goods along railways or railroads. ... Bangkok Skytrain. ... Police officer on a bicycle Cycling is a means of transport, a form of recreation, and a sport. ... This article does not cite any references or sources. ... Transportation planning is the field involved with the siting of transportation facilities (generally streets and highways and public transport lines). ... This thermogram compares a traditional building (left) to one built to the German passive house standard (right) Generically, a low-energy house is any type of house that uses less energy than a regular house. ... A spiral type compact fluorescent lamp. ... Daylighting is the practice of placing windows, or other transparent media, and reflective surfaces so that, during the day, natural light provides effective internal illumination. ... Common insulation applications inside an apartment building in Mississauga, Ontario, Canada. ... Passive solar building design involves the modeling, selection and use of appropriate passive solar technologies to maintain the building environment at a desired temperature range (usually based around human thermal comfort) throughout the suns daily and annual cycles. ... Active solar is a term which refers to the use of solar energy to actively convert the energy in sunlight into other forms. ... A Smart meter generally refers to a type of advanced meter (usually an electrical meter) that identifies consumption in more detail than a conventional meter, and optionally communicates that information via some network back to the local utility for monitoring and billing purposes. ... The CIS Tower, Manchester, England, was clad in PV panels at a cost of £5. ... Heat recovery ventilation (also known as a heat exchanger, air exchanger or air-to-air exchanger) is a ventilation system that employs a counter-flow heat exchanger between the inbound and outbound air flow. ... A regenerative brake is a mechanism that reduces vehicle speed by converting some of its kinetic energy into electrical energy. ... The international recycling symbol. ... For other uses, see Cement (disambiguation). ... For other uses, see Ammonia (disambiguation). ... For other uses, see Iron (disambiguation). ... For other uses, see Electrode (disambiguation). ... Fertilizers or fertilisers are compounds given to plants with the intention of promoting growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar spraying, for uptake through leaves. ... An energy crop is a plant domesticated for use in agriculture and is produced as a low cost and low maintenance harvest (generally, non food crops) to be used to make biofuels or directly exploited for its energy content. ... Fossil fuels or mineral fuels are fossil source fuels, this is, hydrocarbons found within the top layer of the earth’s crust. ... In agriculture, crop yield (also known as agricultural output) is a measure of the yield per unit area of land under cultivation. ... A decidous beech forest in Slovenia. ... This article is about a community of trees. ... Afforestation is the process of converting open land into a forest by planting trees or their seeds. ... Biodiversity on a 15-year-old reforested plot of land. ... Forest management includes a range of human interventions that affect forest ecosystems. ... This article is about the process of deforestation in the environment. ... Waste inside a wheelie bin Waste in a bin bag Waste, rubbish, trash, garbage, or junk is unwanted or undesired material. ... Biogas-bus in Bern, Switzerland Biogas typically refers to a (biofuel) gas produced by the anaerobic digestion or fermentation of organic matter including manure, sewage sludge, municipal solid waste, biodegradable waste or any other biodegradable feedstock, under anaerobic conditions. ... Waste-to-energy (WtE) or energy-from-waste (EfW) in its strictest sense refers to any waste treatment that creates energy in the form of electricity or heat from a waste source that would have been disposed of in landfill, also called energy recovery. ... An active compost heap, steaming on a cold winter morning. ... Sewage treatment is the process that removes the majority of the contaminants from waste-water or sewage and produces both a liquid effluent suitable for disposal to the natural environment and a sludge. ... The international recycling symbol. ... This article or section is not written in the formal tone expected of an encyclopedia article. ... Biofiltration is a pollution control technique using living material to filter or chemically process pollutants. ... This article or section does not cite its references or sources. ... Energy security, or security of supply, is a key component of energy policy in many countries. ...

The IPCC considered that achieving these reductions would require a 'large shift in the pattern of investment, although the net additional investment required ranges from negligible to 5-10%'.They also concluded that it is often more cost effective to invest in end-use energy efficiency improvement than in increasing energy supply.^[30] For the physical concepts, see conservation of energy and energy efficiency. ...

In terms of electricity generation, the IPCC envisage that renewable energy can provide 30 to 35% of electricity by 2030 (up from 18% in 2005) at a carbon price of up to US$50/t, and that nuclear power can rise from 16% to 18%. They also warn that higher oil prices might lead to the exploitation of high-carbon alternatives such as oil sands, oil shales, heavy oils, and synthetic fuels from coal and gas, leading to increasing emissions, unless carbon capture and storage technologies are employed.^[31] Renewable energy effectively utilizes natural resources such as sunlight, wind, tides and geothermal heat, which are naturally replenished. ... Emissions trading (or cap and trade) is an administrative approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants. ... This article is about applications of nuclear fission reactors as power sources. ... Open pit mining Tar sands, also referred to as oil sand or bituminous sand, is a combination of clay, sand, water, and bitumen. ... Oil shale Oil shale is a general term applied to a fine-grained sedimentary rock containing significant traces of kerogen (a solid mixture of organic chemical compounds) that have not been buried for sufficient time to produce conventional fossil fuels. ... Heavy crude oil is the type of crude oil which is characterised by the presence of high amount of wax in it, as compared to light crude oil which contains a lesser amount of wax. ... Synthetic fuel or synfuel is any liquid fuel obtained from coal, natural gas, or biomass. ...

In the transport sector there was a medium level of agreement and evidence that the multiple mitigation options may be counteracted by increased use, and that there were many barriers and a lack of government policy frameworks.^[32]

There was high agreement and much evidence that, despite many barriers (particularly in the developing countries), new and existing buildings could reduce emissions considerably, and that this would also provide other benefits in terms of improved air quality, social welfare and energy security.^[33]

Mitigation in the long term (after 2030)

The IPCC reported that the effectiveness of mitigation efforts over the next two or three decades would have a large impact on the ability to stabilize atmospheric greenhouse gases at lower levels, and that the lower the ultimate stabilization levels, the more quickly emissions would need to peak and decline.^[34] For example, to stabilize at between 445 and 490ppm (resulting in an estimate global temperature 2 to 2.4^oC above the pre-industrial average) emissions would need to peak before 2015, with 50 to 85% reductions on 2000 levels by 2050.^[35]

There was high agreement and much evidence that stabilization could be achieved by 2050 using currently available technologies, provided appropriate and effective incentives were put in place for their development, acquisition, deployment and diffusion, and that barriers were removed.^[36] For stabilization at lower levels the IPCC agreed that improvements of carbon intensity need to be made much faster than has been the case in the past, and that there would be a greater need for efficient public and private research, development & demonstration efforts and investment in new technologies during the next few decades.^[37] The IPCC points out that government funding in real absolute terms for most energy research programmes has been flat or declining for nearly 20 years, and is now about half the 1980 level.^[38] Delays in cutting emissions would lead to higher stabilization levels and increase the risk of more severe climate change impacts, as more of the current high-emission technologies would have been deployed.^[39] Carbon intensity is the ratio of carbon emissions to economic activity or some other activity. ...

Among the measures that might be used, there was high agreement and much evidence that policies that put a price on the cost of carbon emissions could provide incentives for consumers and producers. Carbon prices of 5 to 65 US$/tCO₂ in 2030 and 15 to 130 US$/tCO₂ by 2050 are envisaged for stabilization at around 550 ppm by 2100.^[40]

AR4 Synthesis Report

A draft version of the AR4 Synthesis Report, Summary for Policymakers (SPM)PDF (6.4 MiB), "Subject to final copyedit", was published 16 November, 2007. “PDF” redirects here. ... MiB redirects here. ... is the 320th day of the year (321st in leap years) in the Gregorian calendar. ...

The Synthesis Report goes one step further [than the first three Climate Change 2007 Working Group Reports]: it is the decisive effort to integrate and compact this wealth of information into a readable and concise document explicitly targeted to the policymakers.

The Synthesis Report also brings in relevant parts some material [sic] contained in the full Working Group Reports over and above what is included in the Summary for Policymakers in these three Reports. It is designed to be a powerful, scientifically authoritative document of high policy relevance, which will be a major contribution to the discussions at the 13th Conference of the Parties in Bali during December 2007. In fact, this Conference was postponed to December to allow the IPCC Synthesis Report to come out first.

– Undated IPCC press release

The six topics^[41][42] addressed in the Synthesis Report are:

1. Observed changes in climate and its effects (Working Groups 1-2).
2. Causes of change (WGs 1, 3).
3. Climate change and its impacts in the near and long term under different scenarios (WGs 1-3).
4. Adaptation and mitigation options and responses, and the inter-relationship with sustainable development, at global and regional levels (WGs 2-3).
5. The long term perspective: scientific and socio-economic aspects relevant to adaptation and mitigation, consistent with the objectives and provisions of the Convention [sic], and in the context of sustainable development (WGs 1-3).
6. Robust findings, key uncertainties (WGs 1-3).

The "Convention" mentioned in Topic 5 is the UN Framework Convention on Climate Change (UNFCCC). The United Nations Framework Convention on Climate Change (UNFCCC) is an international environmental treaty produced at the United Nations Conference on Environment and Development (UNCED), informally known as the Earth Summit, held in Rio de Janeiro in 1992. ... The United Nations Framework Convention on Climate Change (UNFCCC) is an international environmental treaty produced at the United Nations Conference on Environment and Development (UNCED), informally known as the Earth Summit, held in Rio de Janeiro in 1992. ...

The key findings from the AR4 Synthesis Report will be discussed Wednesday 13 December 2007^[43] at the United Nations Climate Change Conference (UNFCCC COP 13--CMP 3) in Bali, Indonesia, which takes place 3-14 December (see UNFCCC home page^[44]). The United Nations Framework Convention on Climate Change (UNFCCC) is an international environmental treaty produced at the United Nations Conference on Environment and Development (UNCED), informally known as the Earth Summit, held in Rio de Janeiro in 1992. ...

Criticism

Main article: Criticism of IPCC AR4

The Fourth Assessment Report has been the subject of criticism. Skeptics of anthropogenic global warming contend that their claims are not sufficiently incorporated in the report. Others regard the IPCC as too conservative in its estimates of potential harm from climate change. The IPCC Fourth Assessment Report (AR4) has been subjected to both scientific and non scientific (process based) criticism. ...

Related to the subject of global warming in general, the IPCC Fourth Assessment Report has been discussed by various bodies such as government officials, special interest groups and scientific organizations; see the article "Politics of global warming" for a thorough discussion of the politics surrounding the phenomenon, and the positions of the various parties involved. The politics of global warming looks at the current political issues relating to global warming, as well as the historical rise of global warming as a political issue. ...

See also

Energy Portal

• Avoiding Dangerous Climate Change – international conference (2005)
• Individual and political action on climate change
• Business action on climate change
• Energy policy
• Energy conservation
• Global climate model
• Post-Kyoto negotiations on greenhouse gas emissions
• Precautionary principle
• World energy resources and consumption

Image File history File links Crystal_128_energy. ... Global carbon dioxide emissions 1800–2000 Global average surface temperature 1850 to 2006 Avoiding Dangerous Climate Change: A Scientific Symposium on Stabilisation of Greenhouse Gases was a 2005 international conference that redefined the link between atmospheric greenhouse gas concentration, and the 2°C (3. ... The issue of human-caused, or anthropogenic, climate change (global warming) is becoming a central focus of the Green movement. ... Business action on climate change includes a range of activities relating to combatting global warming, and to influencing political decisions on global-warming-related regulation, such as the Kyoto Protocol. ... Energy policy is the manner a given entity (often governmental) has decided to address issues of energy development including energy production, distribution and consumption. ... For the physical concepts, see conservation of energy and energy efficiency. ... General Circulation Models (GCMs) are a class of computer-driven models for weather forecasting and predicting climate change, where they are commonly called Global Climate Models. ... The Kyoto Protocol, the worlds first treaty to attempt to address global warming by limiting greenhouse gas emissions, is due to expire at the end of 2012. ... The precautionary principle is a moral and political principle which states that if an action or policy might cause severe or irreversible harm to the public, in the absence of a scientific consensus that harm would not ensue, the burden of proof falls on those who would advocate taking the... World power usage in terawatts (TW), 1965-2005. ...

References

“PDF” redirects here. ... MiB redirects here. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... BBC News is the department within the BBC responsible for the corporations news-gathering and production of news programmes on BBC television, radio and online. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 33rd day of the year in the Gregorian calendar. ... The Monterey County Herald, sometimes referred to as the Monterey Herald, is the major daily newspaper published in Monterey, California and serving Monterey County. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 34th day of the year in the Gregorian calendar. ... Reuters Group plc (LSE: RTR and NASDAQ: RTRSY); pronounced is known as a financial market data provider and a news service that provides reports from around the world to newspapers and broadcasters. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 34th day of the year in the Gregorian calendar. ... “PDF” redirects here. ... A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 99th day of the year (100th in leap years) in the Gregorian calendar. ... “PDF” redirects here. ... A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 121st day of the year (122nd in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 255th day of the year (256th in leap years) in the Gregorian calendar. ... For other uses, see BBC (disambiguation). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 121st day of the year (122nd in leap years) in the Gregorian calendar. ... The Cable News Network, commonly known as CNN, is a major cable television network founded in 1980 by Ted Turner. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 124th day of the year (125th in leap years) in the Gregorian calendar. ... For other uses, see BBC (disambiguation). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 124th day of the year (125th in leap years) in the Gregorian calendar. ... “PDF” redirects here. ... A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... IPCC is science authority for the UNFCCC The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the risk of human-induced climate change. The Panel is open to all... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 130th day of the year (131st in leap years) in the Gregorian calendar. ... “PDF” redirects here. ... MiB redirects here. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... 17 November is also the name of a Marxist group in Greece, coinciding with the anniversary of the Athens Polytechnic uprising. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... 17 November is also the name of a Marxist group in Greece, coinciding with the anniversary of the Athens Polytechnic uprising. ...

External links

• IPCC (Intergovernmental Panel on Climate Change):
  • Home page
  • IPCC Fourth Assessment Report (AR4):
    • Working Group I: The Physical Basis of Climate Change:
      • Home page
      • Summary for Policymakers (SPM)PDF (1.25 MiB), published 2 February 2007
      • Full Report, last updated 5 September 2007
      • Frequently Asked QuestionsPDF (3.7 MiB) — 34-page FAQ extracted from the 11 chapters of the Full Report
    • Working Group II: Impacts, Adaptation and Vulnerability:
      • Home page
      • Summary for Policymakers (SPM)PDF (923 KiB), published 6 April 2007
      • Full Report, published 18 September 2007
    • Working Group III: Mitigation of Climate Change:
      • Home page
      • Summary for Policymakers (SPM)PDF (631 KiB), published 4 May 2007
      • Full Report
    • Synthesis Report:
      • Outline of Topics
      • Draft Summary for Policymakers (SPM)PDF (6.4 MiB), published 16 November 2007
• Ten-webpage summary of the Fourth Assessment Report SPMs by GreenFacts; the webpages as a self-contained 39-page documentPDF (1.06 MiB)
• Commentary about Working Group I Report:
  • The Guardian Article on US political pressure on WGI Report, 27 January 2007
  • UNEP.org Press release: Evidence of Human-caused Global Warming “Unequivocal”, says IPCC, 2 February 2007
  • RealClimate blog — Commentary on Working Group I Summary for Policymakers, 2 February 2007