Monday :: Apr 14, 2008

Cautious Consensus

by Turkana

In the March 14 edition of Science, Susan Solomon and Martin Manning give a broad assessment of the IPCC:

Last year, the Intergovernmental Panel on Climate Change (IPCC) was awarded the Nobel Peace Prize along with Albert Gore Jr., sending a strong message about the importance of the world's future climate. Indeed, for two decades, international scientists and policy-makers contributing to the IPCC process have provided assessments of climate change science, impacts, and mitigation, addressing one of the most far-reaching and complex challenges that society has ever faced. Yet this is no time for the IPCC to rest on its laurels. The climate system continues to change and science continues to improve, so policy must be kept current with our best understanding. Reformulating the science/policy interface should be considered and be open to change but must acknowledge lessons from the past. The factors that have been critical to the success of the IPCC need to be preserved if a rigorous scientific basis is to continue to inform the growing challenge of decision-making on climate change.

The IPCC's assessments have been highly credible to both policy-makers and scientists largely because, despite differences in language and approach between these communities, both groups recognize the importance of multiple reviews of drafts in an open process in which diverse authors, reviewers, and governments do not hide behind a cloak of anonymity. The successive reviews and revisions of complex material, with the broad inputs of many, take time. For instance, after scientists and governments defined its scope, the last Working Group I assessment took 3 years to be developed by 152 authors and then reviewed by more than 600 experts along with dozens of governments. Any move toward more rapid products risks incomplete identification of the range of justifiable views and a consequent reduction of the rigor, clarity, and robustness of the consensus.

Moreover, completion of an IPCC assessment report requires a demanding line-by-line approval of its summary that is critical for its value to policy-makers. This process ensures that key conclusions are accepted by all governments and expressed in language that is both scientifically accurate and useful to policy. It requires Working Group co-chairs and authors with the stature and expertise needed to justify their findings and levels of scientific confidence. The utility of the IPCC also depends on its direct relevance to climate policy decisions, and this sharp clarity of purpose requires that the IPCC avoid becoming entrained in many aspects of broader global change and sustainable development issues.

In other words, the IPCC is so deliberate, and so careful to not publish anything that isn't based on a broad-based consensus, that it is, if anything, conservative in its approach. No wonder James Hansen, head of the Nasa Goddard Institute for Space Studies in New York, and, separately, Roger Pielke Jr., of the Center for Science and Technology Policy Research at University of Colorado, Boulder, Tom Wigley of the National Center for Atmospheric Research, and Christopher Green of the Department of Economics at McGill University, Montreal all concluded that the IPCC actually doesn't go far enough. Critics want you to believe the IPCC is radical, political, and wrong. In fact, it is the exact opposite of all three.

Solomon is co-chair of IPCC Working Group I and a senior scientist at the Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO. Manning is the the former head of the IPCC Working Group I Technical Support Unit and a professor at Victoria University, Wellington, New Zealand.

Turkana :: 7:11 PM :: Comments (3) :: Digg It!