The government review of the second-order draft of “Climate Change 2007: The Physical Science Basis”—the Working Group I contribution to the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report—has been initiated.  The U.S. Climate Change Science Program Office is coordinating the solicitation of comments by U.S. experts and stakeholders to inform development of an integrated set of U.S. Government comments on the report.  The question remains: How will the U.S. Government address the mainstream climate science synthesized in the report? 

The completed and approved IPCC Fourth Assessment Report (referred to as AR4), which is being developed over a period of several years, will be published in 2007.  The periodic assessment reports of the IPCC form the scientific underpinning for the development of international agreements to address the problem of global climate change.  IPCC reports are generally accepted and recognized as the most comprehensive, authoritative scientific assessments of climate change.  They are prepared by international teams of hundreds of leading scientists and vetted through multiple stages of expert review before final approval and publication.  As editor Bud Ward has put it:  “Among all the bewildering, competing, and often uninformed voices on climate change, virtually all would put the IPCC at the head of the class when it comes to representing the closest one can come to a scientific ‘mainstream’ perspective.”* 

In the government and expert review of the draft IPCC AR4 we will, for the first time, see how the current administration synthesizes the review by federal scientists, as well as nongovernmental experts and stakeholders who also submit comments, into a formal U.S. Government review to be submitted to the IPCC.  The administration’s record thus far of evasiveness, denial, and misrepresentation of the key conclusions of the last comprehensive IPCC assessment—the Third Assessment Report (TAR), issued in 2001—gives grounds for skepticism about how they will handle this review.

With the IPCC Third Assessment Report, the Working Group 1 report “Climate Change 2001: The Scientific Basis,” was compiled betwen July 1998 and January 2001.  The draft report was circulated for review by hundreds of experts, followed by another stage of review by governments and experts, though which several hundred more reviewers participated. Review comments were assimilated into a revised document for consideration at a session of IPCC held in January 2001.  There the Summary for Policymakers was approved in detail and the underlying scientific report accepted.

So the IPCC Third Assessment Report was approved and published before the current administration and its climate change science and policy apparatus was in place.  With IPCC AR-4, the U.S. Government must either acknowledge the reality of the mainstream scientific consensus on climate change, or explain why not.  Stay tuned.

Some background from the Climate Change Science Program Web site:

The IPCC was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988. In accordance with its mandate and as reaffirmed in various decisions by the Panel, the major activity of the IPCC is to prepare comprehensive and up-to-date assessments of policy-relevant scientific, technical, and socio-economic information relevant for understanding the scientific basis of climate change, potential impacts, and options for mitigation and adaptation.

Three working group volumes and a synthesis report comprise the Fourth Assessment Report, with all to be finalized in 2007. Working Group 1 assesses the scientific aspects of the climate system and climate change; Working Group II assesses the vulnerability of socio-economic and natural systems to climate change, potential negative and positive consequences, and options for adapting to it; and Working Group III assesses options for limiting greenhouse gas emissions and otherwise mitigating climate change. These assessments are based upon the peer-reviewed literature and are characterized by an extensive and open review process involving both scientific/technical experts and governments before being accepted by the IPCC.

On behalf of the U.S. Department of State, the Climate Change Science Program Office (CCSPO) is coordinating the solicitation of comments by U.S. experts and stakeholders to inform development of an integrated set of U.S. Government comments on the report. To be considered in development of the U.S. position, comments must be received at CCSPO by close of business 9 May 2006.  The draft material has not been accepted or approved by the Panel and is being provided on request for the sole purpose of Expert and Government Review. PLEASE DO NOT CITE, QUOTE, OR DISTRIBUTE THE DRAFT REPORT.

*[IT] Reporting on Climate Change: Understanding the Science, Third Edition. (Environmental Law Institute [LINK—]http://www.eli.org], Washington, D.C., 2003)