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….

…While everyone concedes that the Earth is about a degree Celsius warmer than it was a century ago, the debate continues over the cause and consequences. We don’t deny that carbon emissions may play a role, but we don’t believe that the case is sufficiently proven to justify a revolution in global energy use. The economic dislocations of such an abrupt policy change could be far more severe than warming itself, especially if it reduces the growth and innovation that would help the world cope with, say, rising sea levels. There are also other problems–AIDS, malaria and clean drinking water, for example–whose claims on scarce resources are at least as urgent as climate change.

The IPCC report should be understood as one more contribution to the warming debate, not some definitive last word that justifies radical policy change. It can be hard to keep one’s head when everyone else is predicting the Apocalypse, but that’s all the more reason to keep cool and focus on the actual science.