According to a new synthesis report on “Temperature Trends in the Lower Atmosphere,” previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere that have been used to challenge the validity of climate models and the reality of human-induced global warming have been resolved. The report, commissioned by the U.S. Climate Change Science Program and drafted by the leading scientists in this research area, concludes that recent evidence has increased confidence in the understanding of observed climatic changes and their causes.
The report is undergoing a final political-level review and has not yet been approved for release as an official U.S. Government publication. But the report, as drafted and submitted by the scientists, has been posted on the U.S. Climate Change Science Program (CCSP) Web site.
Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences. Thomas R. Karl, Susan J. Hassol, Christopher D. Miller, and William L. Murray, editors, 2006. A Report by the Climate Change Science Program and the Subcommittee on Global Change Research, Washington, DC.
The posted Abstract of the reports reads:
Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the validity of climate models and the reality of human-induced global warming. Specifically, surface data showed substantial global-average warming, while early versions of satellite data showed little or no warming above the surface. There is no longer evidence of such a discrepancy. This is an important revision to and update of the conclusions of earlier reports from the U.S. National Research Council and the Intergovernmental Panel on Climate Change.
Since those reports, errors have been identified and corrected in the satellite data and other temperature observations. These data now show global average warming in the atmosphere similar to the warming observed at the surface and consistent with the results from climate models, although discrepancies remain to be resolved in the tropics. The recent evidence has increased confidence in our understanding of observed climatic changes and their causes.
Of the 21 prospective “Synthesis and Assessment Products” on various topics related to climate change that were identified in the Strategic Plan for the Climate Change Science Program in July 2003, the Temperature Trends report is the first, almost three years later, to reach the stage of having a completed report by scientific experts submitted for publication.
The CCSP Web site explains:
Temperature Trends in the Lower Atmosphere:
Steps for Understanding and Reconciling Differences
This…revised 3rd draft of CCSP Synthesis and Assessment Product 1.1 was completed in accordance with the rules of the Federal Advisory Committee Act….In conformance with Guidelines for Producing CCSP Synthesis and Assessment Products, the final version of CCSP Synthesis and Assessment Product 1.1 will be released subsequent to consideration and approval by the CCSP Interagency Committee and the National Science and Technology Council.
What this means is that this draft must undergo a final political-level editorial review and clearance before it is released for publication as an official U.S. Government report. In previous writing and speaking we have fundamentally questioned the wisdom of having climate change synthesis reports be government publications, rather than commissioning and accepting the reports as written by independent scientific experts and letting the chips fall where they may. In particular we have questioned the integrity and credibility of the guidelines under which the CCSP reports must be produced and approved, which have created a convoluted and delay-ridden bureaucratic process and which create opportunities for politicization of science communication. Entries on this blog dated June 2, 2005 (“On Issues of Concern About the Governance and Direction of the Climate Change Science Program”) and January 4, 2006 (“Toward a Second U.S. National Climate Change Assessment”) discuss these points in some detail. These problems remain.
But from what we have read so far, it looks like the Temperature Trends report will actually make a valuable contribution to the climate change assessment literature. Tom Karl, the Director of the NOAA National Climatic Data Center and Lead Editor and co-author of the report, deserves a lot of credit for this work, as does the rest of the author team. During the course of developing the report, several of the authors published new research in the scientific literature that significantly advanced understanding of the temperature trends discrepancy problem and went far toward resolving key issues—thereby fundamentally undercutting the basis of an argument that had been used for years by global warming contrarians in saying there was no consistent evidence of warming. And now that the scientists’ draft has been posted on the Web, hopefully this report, at least, will escape the political tampering that has characterized some of the earlier publications that have come out of the CCSP.