'Unequivocal." That's quite a claim in this skeptical era, so it's been enlightening to watch the unraveling of the absolute certainty of global warming caused by man. Now even authors of the 2007 United Nations report that "warming of the climate system is unequivocal" have backed off its key assumptions and dire warnings.

Science is having its Walter Cronkite moment. Back when news was delivered by just three television networks, Walter Cronkite could end his evening broadcast by declaring, "And that's the way it is." The Intergovernmental Panel on Climate Change (IPCC) report likewise purported to proclaim the final word, in 3,000 pages that now turn out to be less scientific truth than political cover for sweeping economic regulations.

Equivocation has replaced "unequivocal" even among some of the scientists whose "Climategate" emails discussed how to suppress dissenting views via peer review and avoid complying with freedom-of-information requests for data.