The World Meteorological Organization and the United Nations Environment Program created an intergovernmental committee to study climate change and to analyze the effects of such change on human beings and on the environment.
The Intergovernmental Panel on Climate Change (IPCC) was conceived in 1987 and established formally in 1988 by the World Meteorological Organization
The WMO was formed on March 23, 1950, as a result of a meeting of the directors of the National Meteorological Services in Washington, D.C., in September and October, 1947. The first WMO congress met in March, 1951, in Paris, France. There, the organization formed an executive council, technical commissions, and regional associations, and officers were elected. The WMO also established technical programs to satisfy the purposes of the organization.
Programs of the WMO are separated into two overlapping time scales: long-term programs and medium-term plans. Long-term programs extend for ten-year periods and are revised every four years. These plans set forth overall policies as well as develop the necessary strategies and priorities for completing them. Medium-term plans of four-year periods prepare the budgets for the first four years of the long-term plans.
UNEP was formed in 1972 after the U.N. Human Environment Conference. The program’s aim is to coordinate intergovernmental measures for monitoring and protecting the environment. Uppermost in significance are issues concerning climate change that involve participation in the International Program for Climate Change and the world climate program and membership in the Advisory Group on Greenhouse Gases (AGGG). UNEP is the lead agency of the Vienna Convention and the Montreal Protocol,
The IPCC first met in November, 1988, in Geneva, Switzerland. At that meeting, three working programs were established; these were later joined by a task force. Working Group I assesses available scientific information relating to climate change, specifically greenhouse gases. This group studies responses to these factors by the atmosphere-ocean-land-ice system and assesses the capabilities of modeling global and regional climate change and the models’ degree of predictability. Group I examines past climate records and current climate anomalies, predictions of future climate changes and their timing, and changes in sea levels. This group identifies the range of projections and how they vary regionally; it also studies gaps in projections and uncertainties.
Working Group II reviews environmental and socioeconomic impacts of climate change in an integrated manner and evaluates the impacts on national and regional scales of climate warming and sea-level rise. Group II evaluates impacts of climate change on agriculture, health, forestry, water resources, and energy, especially the impacts of floods, droughts, and desertification.
Working Group III focuses on policy development as it relates to future emissions of greenhouse gases, impacts of changing technology, sources and sinks of gases, adaptation to climate change, strategies for control or reduction of emissions of greenhouse gases and other human activities affecting climate change, and the socioeconomic and legal implications of these human activities. The Task Force on National Greenhouse Gas Inventories, with a Bureau and fourteen members, oversees the IPCC’s program concerning greenhouse gas inventories around the world.
In June, 1989, the IPCC held its second meeting in Nairobi, Kenya. The panel set up a special committee to deal with matters related to developing countries. The three working groups made reports in May and June, 1990, and drafted printed summaries for policy makers. The third meeting of the IPCC occurred in Washington, D.C., in February, 1990, and its fourth meeting was held in Sundsvall, Sweden, in August, 1990. Since that time, the IPCC has continued to meet in plenary sessions about once a year.
The first IPCC “assessment report,” presented by Working Group I of the IPCC in May and June of 1990, indicated that a natural greenhouse effect maintains Earth temperatures at a level somewhat warmer than they would be in the absence of this effect. The report noted that emissions from human activities had been increasing concentrations of greenhouse gases in the atmosphere for some time. Increasing concentrations of these gases—carbon dioxide (CO
2
), methane, chlorofluorocarbons (CFCs), and nitrous oxide—enhance the greenhouse effect and cause Earth temperatures to rise. Moreover, the main natural greenhouse gas, water vapor, was expected to increase as the planet warms, enhancing the effect. Some greenhouse gases were noted to be more effective than others at warming the climate. CO
2
, the report noted, is responsible for more than 50 percent of the warming and is expected to continue to be the most influential. Other greenhouse gases (methane, nitrous oxides, and CFCs) have long half-lives in the atmosphere and change slowly as emissions vary.
The IPCC established four potential responses to this assessment of climate change, from no effort to control emissions to varying efforts to reduce emissions. Scenario A, with no emission control, projected a doubling of preindustrial levels of CO
2
by the year 2025. Scenario B, which assumed some emission control, would double CO
2
by 2040, and Scenario C, with the addition of more emission controls, would double CO
2
by 2050. Scenario D, with stabilization of CO
2
at double the preindustrial level, would occur near the end of the twenty-first century. For concentrations of long-lived greenhouse gases to be stabilized, net emissions from human activities would have to be reduced immediately by 60 percent. Methane concentrations could be stabilized with a 15 to 20 percent reduction of emissions.
Human-produced emissions of carbon dioxide are smaller than the natural exchange rates of CO
2
between the hydrosphere (oceans) and the atmosphere, and between the lithosphere (land) and the atmosphere. Natural exchange rates, however, were in balance prior to the addition of human-induced emissions. The increase attributable to human-caused emissions of CO
2
could have a substantial impact on the natural carbon cycle.
At the time the IPCC issued its first assessment report, atmospheric models predicted that, over the next century, the global mean temperature would increase at nearly 0.03 degrees Celsius per decade, with an uncertainty range of 0.02-0.05 degrees Celsius per decade, a prediction based on Scenario A. This rate of increase in temperature would be more rapid than any that has occurred over the past ten thousand years. This rate of increase could mean a rise in mean global temperature of nearly 1 degree Celsius by 2025 and an increase of about 3 degrees Celsius by the end of the twenty-first century. This rise would not be steady because of other factors. Under Scenario B, the mean global temperature would increase about 0.02 degrees Celsius per decade. Scenario C would produce an increase of slightly more than 0.01 degrees Celsius per decade, and Scenario D would result in a rise of nearly 0.01 degrees Celsius per decade. Temperature increases in the Northern Hemisphere would not be steady because land heats more rapidly than water, and high northern latitudes heat more than the global mean in winter. Further, oceans, which serve as heat sinks, would mitigate and therefore delay the full effect of greenhouse warming. As a result, a further temperature increase would become increasingly apparent over time.
At the time the report was issued, predictions by climate models of the amount of global warming were consistent with the magnitude of the warming that had occurred over the preceding century. The amount of warming, however, was consistent with the natural variability of climate. If the warming were a result of the human-caused greenhouse effect only, temperature increases would register near the lower end of the range predicted by models. Natural climatic variability thus might have explained the majority of the increase in temperature, and climate variability and human factors might have been expected to offset a much larger rise in human-induced greenhouse warming. Since 1990, the study of ice cores taken from Antarctica has persuaded most scientists that global warming is directly related to human activity and that it is proceeding at a precipitous rate.
The IPCC’s mandate is “to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.” Hence, although the IPCC does not conduct research or monitor climate-related data, it continues to prepare and publish special, technical, and assessment reports. The first IPCC assessment report, for example, led the General Assembly of the United Nations to create the Intergovernmental Negotiating Committee for a U.N. Framework Convention. Adopted in 1992, the U.N. Framework Convention on Climate Change
After issuing its first assessment report in 1990, the IPCC issued a supplementary report in 1992 and several more assessment reports, including those in 1995, 2001, and 2007. Each report consists of reports from Working Groups I, II, and III and the Task Force. Of these, the report that attracts most attention is often the scientific report, issued by Working Group I. In 2007, this report noted that “warming of the climate system is unequivocal.” Based on scientific, peer-reviewed literature, the reports have become widely cited in studies of global climate change and hence very influential, offering a standard against which scientists can assess the state of the global climate and on which policy makers can base decisions.
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Bolin, Bert. A History of the Science and Politics of Climate Change: The Role of the Intergovernmental Panel on Climate Change. New York: Cambridge University Press, 1997. Overview of the history of the IPCC by the organization’s first chairman. Provides informative discussion of the debates surrounding the topic of climate change. -
Houghton, John Theodore, B. A. Callander, and S. K. Varney, eds. The Supplementary Report to the IPCC Scientific Assessment. New York: Cambridge University Press, 1992. Covers the second assessment report of the IPCC to the U.N. governing bodies. -
Houghton, John Theodore, G. J. Jenkins, and J. J. Ephraums, eds. Climate Change: The IPCC Scientific Assessment. New York: Cambridge University Press, 1990. Provides a detailed account of the report of the IPCC to the panel’s governing bodies. -
Intergovernmental Panel on Climate Change. Climate Change 2007: Mitigation of Climate Change—Working Group III Contribution to the Fourth Assessment Report of the IPCC. New York: Cambridge University Press, 2007. -
_______. Climate Change 2007: The Physical Science Basis—Working Group I Contribution to the Fourth Assessment Report of the IPCC. New York: Cambridge University Press, 2007. These two volumes in the 2007 (fourth) assessment report of the IPCC offer science-based, comprehensive, and objective evaluations of policy issues related to climate change. These are the standard reference works, written by the most knowledgeable experts in the field. -
_______. Safeguarding the Ozone Layer and the Global Climate System: Issues Related to Hydrofluorocarbons and Perfluorocarbons. New York: Cambridge University Press, 2005. Special report provides the scientific context necessary for understanding the alternatives to ozone-depleting substances. -
Skodvin, Tora. Structure and Agent in the Scientific Diplomacy of Climate Change: An Empirical Case Study of Science-Policy Interaction in the Intergovernmental Panel on Climate Change. Boston: Kluwer Academic, 2000. Focuses on the IPCC in analyzing the interaction between scientific research results and the use of those results in policy making.
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