E6-5131. United States Climate Change Science Program

The United States Climate Change Science Program requests expert review of the Working Group I contribution (“Climate Change 2007: The Physical Science Basis”) to the Intergovernmental Panel on Climate Change Fourth Assessment Report.

The Intergovernmental Panel on Climate Change (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. The First Assessment Report was completed in 1990, the Second Assessment Report in 1995, and the Third Assessment Report in 2001. Three working group volumes and a synthesis report comprise the Fourth Assessment Report, with all to be finalized in 2007. Working Group I 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.

The IPCC Secretariat has informed the U.S. Department of State that the second-order draft of the Working Group I contribution to the Fourth Assessment Report is available for Expert and Government Review. The Climate Change Science Program Office (CCSPO) is coordinating collection of U.S. expert comments and the review of these collations by panels of Federal scientists and program managers to develop a consolidated U.S. Government submission. Instructions on how to format comments are available at http://www.climatescience.gov/​Library/​ipcc/​wg14ar-review.htm, as is the document itself and other supporting materials. Comments must be sent to CCSPO by May 9, 2006 to be considered for inclusion in the U.S. Government collation. Comments submitted for potential inclusion or consideration as part of the U.S. Government Review should be reserved for that purpose, and not also sent to the IPCC Working Group I Technical Support Unit as a discrete set of expert comments.

Properly formatted comments should be sent to CCSPO at [e-mail] by COB Tuesday, 9 May 2006. Include report acronym and reviewer surname in e-mail subject title to facilitate processing.

For further information, please contact David Dokken, U.S. Climate Change Science Program, Suite 250, 1717 Pennsylvania Ave, NW., Washington, DC 20006 (http://www.climatescience.gov).

Dated: April 3, 2006.

Trigg Talley,

Office Director, Acting, Office of Global Change, Bureau of Oceans and International Environmental and Scientific Affairs, Department of State.