A calm look, instead of the recent hysteria, about the conclusions reached by the UN Report on global warming.
Climate of Opinion
The latest U.N. report shows the "warming" debate is far from settled.
Monday, February 5, 2007 12:01 a.m. EST
Last week's headlines about the United Nations' latest report on global warming were typically breathless, predicting doom and human damnation like the most fervent religious evangelical. Yet the real news in the fourth assessment from the Intergovernmental Panel on Climate Change (IPCC) may be how far it is backpedaling on some key issues. Beware claims that the science of global warming is settled.
The document that caused such a stir was only a short policy report, a summary of the full scientific report due in May. Written mainly by policymakers (not scientists) who have a stake in the issue, the summary was long on dire predictions. The press reported the bullet points, noting that this latest summary pronounced with more than "90% confidence" that humans have been the main drivers of warming since the 1950s, and that higher temperatures and rising sea levels would result.
More pertinent is the underlying scientific report. And according to people who have seen that draft, it contains startling revisions of previous U.N. predictions. For example, the Center for Science and Public Policy has just released an illuminating analysis written by Lord Christopher Monckton, a one-time adviser to Margaret Thatcher who has become a voice of sanity on global warming.
Take rising sea levels. In its 2001 report, the U.N.'s best high-end estimate of the rise in sea levels by 2100 was three feet. Lord Monckton notes that the upcoming report's high-end best estimate is 17 inches, or half the previous prediction.
Similarly, the new report shows that the 2001 assessment had overestimated the human influence on climate change since the Industrial Revolution by at least one-third.
Such reversals (and there are more) are remarkable, given that the IPCC's previous reports, in 1990, 1995 and 2001, have been steadily more urgent in their scientific claims and political tone. It's worth noting that many of the policymakers who tinker with the IPCC reports work for governments that have promoted climate fears as a way of justifying carbon-restriction policies. More skeptical scientists are routinely vetoed from contributing to the panel's work. The Pasteur Institute's Paul Reiter, a malaria expert who thinks global warming would have little impact on the spread of that disease, is one example.
