IPCC enters new stage of Fifth Assessment Report review (IPCC)

GENEVA, 5 October – The Intergovernmental Panel on Climate Change (IPCC) is moving to a new stage in the preparation of its next major report, the Fifth Assessment Report, with the first of three government and expert reviews that will take place between now and May 2013.

The multi-stage review of draft reports is a key element of the IPCC assessment process. The main stages are the review of the first order draft by scientific experts, the review of the second order draft by Governments and experts, which starts today, and a final round of government comments on the draft Summary for Policymakers.

In the second stage of the review, IPCC member Governments are invited to review the second order drafts of the reports. Individuals with relevant expertise may also provide expert comments. The purpose of this government and expert review is to help ensure that the report represents the latest scientific and technical findings, provides a balanced and comprehensive assessment of the current information and is consistent with the mandate of the working groups and the outline of the Fifth Assessment Report that was approved by the Panel in October 2009.

  • For Working Group I, which covers the physical science basis of climate change, the government and expert review of the second order draft runs from 5 October to 30 November 2012. Further details are available at https://sod.ipcc.unibe.ch/registration/.
  • The government and expert review period for the second order draft of Working Group II, covering impacts, adaptation and vulnerability, will run from 29 March to 24 May 2013. More information will be available at www.ipcc-wg2.gov closer to that time.
  • Working Group III, which assesses the mitigation of climate change, will hold the government and expert review of its second order draft from 25 February to 22 April 2013. Further information will be available nearer the time at www.ipcc-wg3.de/ .

The number of experts involved in the review of the first order draft of the three IPCC working groups ranged from 563 to 659 for each working group, resulting in between 16,124 and 21,400 comments for each working group’s draft. Report authors must respond to each comment and they draw on the comments to produce the second order drafts. Experts who took part in this review are also invited to comment on the second order draft.

Following the multi-stage review, the Summary for Policymakers and the full report are submitted for approval and acceptance to the IPCC Plenary, its main decision-taking body. To ensure transparency, all review comments and author responses are made available on the IPCC website after the reports are accepted and finalized.

Working Group I will release its Summary for Policymakers in September 2013. Working Group II will release its Summary for Policymakers in March 2014, followed by Working Group III in April 2014. The Synthesis Report, that synthesizes key findings from the assessment reports of the IPCC’s three working groups and from recent Special Reports, is due to be released in October 2014, marking the end of the current assessment cycle.