In a better world, debates about science — and nearly everything else — would be conducted without resort to demagoguery, sentimentality, cynical manipulation, or hysteria. In the world we inhabit, those tactics are dismayingly routine. Still, the great weakness of overwrought predictions of doom is that they can be checked.

The past year has not been kind to the most potent symbols of climate change hysteria. Consider the polar bears. Among the most moving images of the warmists’ warnings was the solitary polar bear, supposedly marooned on an ice floe. The image became iconic after it was published in Science Magazine. Among the most memorable moments in Al Gore’s film, “An Inconvenient Truth,” was an animated clip depicting struggling polar bears.