The May 1, 2008 issue of New Scientist magazine has an interesting article that parallels some of the discussions that we’ve had on this site lately. Here is an interesting excerpt:

“Politicians seems to think that the science is a done deal,” says Tim Palmer, “I don’t want to undermine the IPCC, but the forecasts, especially for regional climate change, are immensely uncertain”.

Palmer is a leading climate modeller at the European Centre for Medium-Range Weather Forecasts in Reading, UK, and he does not doubt that the Intergovernmental Panel on Climate Change (IPCC) has done a good job alerting the world to the problem of global climate change. But he and his fellow climate scientists are acutely aware that the IPCC’s predictions of how the global change will affect local climates are little more than guesswork. They fear that if the IPCC’s predictions turn out to be wrong, it will provoke a crisis in confidence that undermines the whole climate change debate.

The IPCC’s forecasts could be wrong in many different ways, over different time periods and spatial scales, including underestimating future changes. And it is not even clear that scientists involved with the IPCC have a collective view on what it would even mean for the IPCC to be “wrong”. As we’ve argued here often, action on climate change makes sense even if the predictions of the IPCC are not yet perfect. But this is a hard case to make when defenders of those predictions allow no room for imperfections to be seen, or questions to be asked.