Some global warming alarmists, including a few scientists, are complaining about the forthcoming Fourth Assessment Report by the United Nations Intergovernmental Panel on Climate Change (IPCC). Apparently, the twenty-odd page Summary for Policymakers isn't alarming enough for them. Thus, after years of establishing the IPCC reports as representing the scientific consensus -- from which there is no appeal and upon which thousands of the world's top scientists work and about which all agree that it's perfect -- now the alarmists are trying out a new song and dance. To wit: The Assessment Reports are the work of the establishment and therefore can only come to very "conservative" conclusions so as not to offend anyone. Tell that to Dr. R. K. Pachauri, the chairman of the IPCC, who announced early in his tenure that the problem with the first three Assessment Reports is that they didn't have enough scary material to promote the Kyoto agenda and promised that the Fourth would be different. That may still be the case since the thousand-or-so page Working Group 1 report won't be published until May or June. But the Summary for Policymakers, which is not produced by the scientists but by the member governments of the IPCC, is due to be released on Friday, 2nd February. Apparently, it doesn't have any smoking gun headline comparable to the now discredited hockey stick that was featured in the Summary for the Third Assessment Report in 2001 or Ben Santer's intentionally misleading graph featured in the Second. That's too bad for the alarmists because the Summary is what the media read and what the public hears about. The funny thing about the claims of scientific consensus -- and especially the references to the IPCC as representing that consensus -- is that it only works to silence people who are less alarmist. Al Gore, Sir David King, and James Hansen (a former elected leader, a chemist, and an astronomer, respectively) can make outlandish claims about sea level rise, but if I, as a non-climatologist, refer to the authoritative Third Assessment Report, which predicts 20 inches by 2100, not 20 feet (or 80 in Hansen's case), guess who's outside the mainstream? I'm called a denier. The claims about the Greenland or Antarctic ice sheets melting are less likely than the claim that the world is about to enter a cooling period, which claim at least has some research supporting it. If winter low temperatures rise in the polar regions, as is predicted by greenhouse theory, there won't be any melting because it will still be below freezing, but there will be more days when it's warm enough to snow. Of course, on the other hand, the ice sheets have been melting and sea levels have been rising at varying rates since the end of the last ice age and will continue to do so until the next ice age begins. So eventually Gore et al. could be proved right, but I'd rather see a few more thousand years of melting than a new ice age. It's interesting to look at the complainers. Professor John Turner talks about the Antarctic Peninsula, where it has been warming significantly, but nearly all the ice is on the continent, where temperatures have been generally stable or cooling, according to the British Antarctic Survey weather station data (easily found on their website). Is he being intentionally misleading? Professor Lonnie Thompson is not a polar ice expert, but a tropical glaciers expert, and his claims in the public debate seem to go far beyond his research. Dr. Robert Corell is an oceanographer who spent his career as a scientific administrator. He was chairman of the Arctic Climate Impact Assessment, which redefined the Arctic in order to show a bigger warming trend and cut off the temperature record before 1950 so that they wouldn't have to explain why it was at least as warm in the 1930s as today in the Arctic (the reason claimed is a hoot: there weren't enough weather stations before 1950 -- even though there were more then than in recent decades). Michael MacCracken is I believe a computer modeller, whose main claim to fame is that he was one of the top people who produced the infamous National Assessment on the Impacts of Climate Change (2001), which is a bad joke and which was the target of two moderately successful CEI lawsuits in federal court.