IPCC Fourth Assessment Report

November 28, 2012, 8:31 am
Source: United.nations

Intergovernmental Panel on Climate Change

The Intergovernmental Panel on Climate Change (IPCC) is the leading body for the assessment of climate change, established by the United Nations to provide the world with a clear, balanced view of the present state of understanding of climate change.

The main activity of the IPCC is to provide in regular intervals Assessment Reports of the state of knowledge on climate change. The latest one is "Climate Change 2007", the Fourth IPCC Assessment Report.

The IPCC does not conduct research on its own. Its core activity is to review and assess the most recent scientific, technical and socio-economic information relevant to the understanding of climate change.

The IPCC was established in 1988 by the World Meteorological Organization and the United Nations Environment Programme and is open to all their member countries.

The IPCC provides at regular intervals comprehensive, rigorously documented Assessment Reports that summarize the current knowledge and future projections of climate change (CC).

IPCC Assessment Reports

caption IPCC Procedures

IPCC reports are written by teams of authors, nominated by governments and international organizations. They come from universities, research centers, business and environmental associations from all over the world. More than 800 contributing authors and more than 450 lead authors were involved in the writing of the AR4.

Review is an essential part of the IPCC process, to ensure an objective and complete assessment of current information. More than 2.500 scientific expert reviewers were involved in the two-stage scientific and technical review process of the AR4.

For the first review, the drafts are circulated to specialists with significant expertise and publications in the field. A wide circulation process ensures contributions from independent experts in all regions of the world and all relevant disciplines. Revised drafts are distributed for the second review to governments and to all authors and expert reviewers. Governments and expert reviewers can provide comments on the accuracy and completeness of the scientific/technical/socio-economic content and the overall balance of the drafts. Differing views for which there is significant scientific or technical support are clearly reflected in the final documents.

Full reports are accepted during the Working Group's plenary, while for each report a Summary for Policymakers is approved line by line. The SPM therefore represents the point of agreement: participating governments acknowledge that there is enough scientific evidence worldwide to support the document's statements. Thanks to the depth of its scientific work and to the value of its intergovernmental nature, IPCC work is very much policy relevant. Its assessment reports played a decisive role in inducing governments to adopt the United Nations Framework Convention on Climate Change and the Kyoto Protocol. However, IPCC is neutral with respect to policy and its assessment reports are not policy prescriptive.

Climate Change 2007: the Fourth Assessment report

"Climate Change 2007" is the 4th IPCC's Assessment Report (AR4). The previous ones were published in 1990; 1995 and 2001.

The IPCC 4th Assessment Report (AR4) consists of four volumes that released in during 2007. The volumes were released according to the following schedule:

  • February 2 (Paris) - "The Physical Science Basis"
  • April 6 (Brussels) - "Impacts, Adaptation and Vulnerability"
  • May 4 (Bangkok) - "Mitigation of Climate Change"
  • November 17 (Valencia) - "The Synthesis Report"

Compared to the 2001 report, the AR4 pays greater attention to the integration of climate change with sustainable development and the inter-relationships between mitigation and adaptation. Specific attention is given to regional issues, uncertainty & risk, technology, climate change & water.

Synthesis Report

The Synthesis Report summarizes the findings of all three Working Group reports in 23 pages.

List of Authors

(Click on link above to obtain list of authors)

IPCC Fourth Assessment Report (AR4) Table of Contents

(AR4 section headings below are linked to Adobe Acrobat version of the documents).

Working Group I Report: The Physical Science Basis

Working Group II Report: Impacts, Adaptation and Vulnerability

Working Group III Report: Mitigation of Climate Change

Glossary of Terms used in the IPCC Fourth Assessment Report

Further Reading



(2012). IPCC Fourth Assessment Report. Retrieved from http://www.eoearth.org/view/article/51cbee0f7896bb431f695d04


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