Part I   Part II   Part III   Background   Climate Update 

Update on the Intergovernmental Panel on Climate Change Third Assessment Report (3-13-01)

The Intergovernmental Panel on Climate Change (IPCC) was created in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to "assess the scientific, technical, and socio-economic information relevant for the understanding of the risk of human-induced climate change."  The full panel meets in plenary sessions about once a year to approve IPCC reports, create mandates for the three IPCC working groups, and other business matters. The three working groups of the IPCC meet as necessary to produce reports.  The Panel has released three assessment reports, the most recent in early 2001.  The assessment reports give the state of climate change science, potential impacts of climate change, and mitigation options.

The Third Assessment Report (TAR) of the IPCC was released over the first three months of 2001 as the IPCC working groups completed the final approval process for their submissions to the report.  Each working group report is approximately 1000 pages long; therefore, each group also submits a report summary for policymakers (SPM) that is 10-20 pages in length.   Each chapter of a working report has several lead authors, along with hundreds of contributing authors.  Most of the authors are scientists designated by member governments.  The report is subject to two rounds of intense peer review and final approval from the IPCC members. Scientist authors also write the SPM, which is subject to line by line approval of member government designees.

Part I
Report Summary for Policymakers (SPM) Climate Change 2001: The Scientific Basis was released by IPCC Working Group I in January 2001.  The report was created by 123 lead authors, 516 contributing authors, 21 review editors, and 300 expert reviewers appointed by the governments and organizations that are members of the IPCC.  The SPM presents a dire forecast for future climate change.  Although some important climate indicators such as tropical storm frequency and intensity show no notable trends over the last century, the report contends that atmospheric temperatures have increased in the last four decades.  Temperature increases are causing ice to melt, sea level to rise, increased precipitation, cloud cover, and frequency of El Nino/La Nina events.

According to the report, concentrations of greenhouse gases are also on the rise, and there is strong evidence that human activity is the major cause of the change.  Natural factors have made only small contributions to the temperature rise and the increased concentration of greenhouse gases in the atmosphere.  The report explains the reasons for confidence in recent climate models that predict continued rise in sea level and global average temperature in response to past, present and future human activities.  Critics have been quick to point out the report's heavy reliance on climate model results for its assertions of large temperature increases in the coming century.  Some also question the report's interpretation of existing temperature data. The purpose of the Working Group I report is to present the state of climate change science, although it also states the importance of continued research and monitoring.

Part II
On February 19th, IPCC released the Report Summary for Policymakers (SPM) Climate Change 2001: Impacts, Adaptation, and Vulnerability prepared by Working Group II.  Group II is charged with describing the potential effects of climate change on ecosystems, water resources, and human systems (energy, industry, financial services, and health) as they are presently understood.  The SPM was approved by all 100 IPCC member countries.  Listed below, in report language, are the group's briefly stated general findings:

The report notes the difficulty of separating changes caused by land-use alteration and pollution from changes caused by global warming.  Discerning the impact of increasing human population from the impact of climate change is another challenge to be addressed.  Other uncertainties relate to the future responses of human and natural systems to climate change.  Many of the consequences of global warming will provide improvements in some regions while worsening conditions elsewhere.  It is unclear how much the beneficial changes that occur in one region or season will offset damages that occur in another region or at a different time of the year.  The report recommends that further research include complete regional studies of the effects of climate change.  The speed at which climate change occurs will also play a large role in what adaptation measures are implemented.  According to the SPM, future research should focus on obtaining the information upon which effective policy can be drafted to mitigate the effects of climate change.

Part III
Working Group III of the IPCC released the 1000 page report Climate Change 2001: Mitigation along with its summary for policymakers (SPM) on March 5, 2001.  The first part of the SPM analyzes some of the challenges faced in studying climate change mitigation strategies.  Modeling climate change mitigation is difficult given regional climate variability and the wide range of future emission scenarios.  Different greenhouse gas emissions levels have large effects on the magnitude of warming and therefore the costs of mitigation.  Policy changes implemented to reduce emissions may have large initial economic and societal costs.  Mitigation activities will have affects on and be impacted by other social policies and trends such as sustainability and equity.  Mitigation options employed will be guided by the socio-economic and environmental conditions within a country or region.

The second part of the SPM highlights the options available for reducing concentrations of greenhouse gases in the atmosphere.  Working Group III found that technical advances in greenhouse gas emission -- such as wind turbines, hybrid engine cars, underground carbon dioxide storage -- are progressing faster than anticipated. These technologies could have greater than expected influence on greenhouse gas emission levels. Other technological options for emission reduction include improving the efficiency of "end-use" products, using more low-carbon renewable fuels, improved energy management, and energy conversion technologies.  Another way to reduce greenhouse gas concentrations is through carbon sequestration in forests, agricultural lands, and other ecosystems.  If the sequestration approach is used it must be ensured that future disruptions of these sinks are minimized to prevent carbon release.  With current technology, atmospheric levels of carbon dioxide can be stabilized over the next 100 years if the required institutional and socio-economic changes are made to implement them.

The third part of the SPM is an analysis of the potential costs and benefits of mitigation activities, with a focus on the economic costs of reducing carbon emissions.  Costs of emission reduction will vary depending on the developmental stage of a country as well as the economic sector.  The report found that as atmospheric carbon dioxide levels are reduced, the costs of further reduction become greater.  The costs of mitigation were more easily modeled than the ancillary benefits of carbon reduction techniques such as improved product efficiency and better air quality.

The fourth part of the SPM describes the "ways and means" for climate change mitigation.  The report acknowledges that the effectiveness of mitigation options will vary depending on the "technical, economic, political, social, behavioral and/or institutional" capacity of a particular country or region to embrace new technology and accommodate social or economic change.  Mitigation will be more effective if a range of policy instruments related to a wide range of techniques are employed to reduce atmospheric concentration of greenhouse gases.  Policy tools would be even more effective if they were also used to further other non-climate objectives such as sustainable development.  Combining the mitigation efforts of countries and regions could reduce program costs and increase effectiveness.

The final part of Working Group III's SPM states that continued research in climate change mitigation is needed to "strengthen future assessments and to reduce uncertainties as far as possible in order that sufficient information is available for policy making about responses to climate change."  High priority research areas are in exploration of regional, country, and sector specific social and technological innovation options and the socio-economic issues that governments will face as mitigation techniques are explored.

The assessment reports of the Intergovernmental Panel Climate Change (IPCC) are syntheses of scientific climate change literature put together by scientists and experts from around the world.  The IPCC is an assemblage of governmental designees from 100 industrialized and developing nations.  The panel was created in 1988 by the United Nations Environment Programme and the World Meteorological Organization to provide information for international negotiations on policy issues.  The First Assessment Report, released in 1990 was instrumental in the establishment of the United Nations Framework Convention on Climate Change.  The Second Assessment Report, released in 1996 provided supporting materials for preparation of the Berlin Mandate and the Kyoto Protocol.  The IPCC is now in the process of releasing the Third Assessment Report (TAR).

The IPCC breaks into three working groups for the purpose of drafting reports.  The IPCC does not conduct new research or make policy recommendations. According to its mandate, IPCC reviews published, peer-reviewed scientific literature and synthesizes it to provide a comprehensive, balanced view of the present understanding of many aspects of climate change science.  Each of three working groups is responsible for a part of the climate change issue.  Working Group I is responsible for assessing the state of climate change science, Group II is responsible for assessing the effects of climate change, and Group III for exploring mitigation opportunities.  Two scientific documents -- the technical report and the Report Summary for Policymakers -- are created by each working group for submission to the TAR.

The technical report is drafted chapter by chapter.  Each chapter has a set of lead authors -- mostly scientists -- from different backgrounds and viewpoints, and a set of contributing authors -- mostly researchers who have been asked by the lead authors to submit their work. The lead authors compose a rough draft that is reviewed by a group of "expert reviewers", scientists, and representatives from non-governmental organizations.  A revised edition is then drafted and sent to the member governments for review.  Each government is at its discretion as to how to review the document. For example, the U.S. sends the report to government agencies, and requests public comment through a Federal Register posting.  The lead authors again revise the document before submitting it for approval from the full working group.

In addition to the technical report a much shorter Report Summary for Policymakers (SPM) is submitted by each of the three working groups.  It is subject to extensive discussion with all of the member parties as well as a line by line review and revision by governmental representatives.  The SPM must be approved by a majority of the 100 governments that make up the IPCC.  Historically, all reports have been approved unanimously.  The direct involvement of many governments in the drafting of the IPCC reports is the reason that the reports have been so influential in international action on climate change.  The extensive review process for both the TAR and the SPM are meant to guarantee that the reports are comprehensive, objective, and policy neutral. More information is available on the IPCC and the United Nations Framework Convention on Climate Change websites as well as the U.S. Global Change Research Program website, which is updated every two weeks with new developments in global change issues. See the AGI Update on Climate Change Policy for legislative updates from the 107th Congress. 

Sources:   IPCC Report Summary for Policymakers, IPCC website, Greenwire, Environment and Energy Daily

Please send any comments or requests for information to the AGI Government Affairs Program at

Contributed by Spring 2001 AGI/AAPG intern Mary Patterson

 Posted March 13, 2001

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