A close reading of some of the key passages shows that it cannot bear the weight of the sensationalized parts of the SPM, at least as rendered in the media. One of the most misleading aspects of this story is the way in which the SPM conveys a “95 percent confidence” or certainty of its findings, as though this figure represented a rigorous or robust test familiar to first-year students of statistical correlation. The IPCC’s methodology behind these conclusions is thoroughly opaque. When you strip away the fog, the IPCC admits these conclusions are “qualitative,” and based essentially on a poll of the self-selecting participants in the IPCC review process itself.
This is like polling the Romney campaign staff about how confident they are their candidate will win the election, and representing it as the firm “consensus” of all political scientists. The IPCC’s main report finally admits that the methodology for their confidence calibrations is derived from social science, and that “confidence should not be interpreted probabilistically, and it is distinct from ‘statistical confidence.’ ” You won’t see this admission reflected in any of the breathless news reports about the IPCC’s high confidence of our future doom.