Thursday, August 16, 2007

Response to Dyson's climate skepticism

Earlier this month, Carbon-Based posted a link to Freeman Dyson's skeptical thoughts about climate models, courtesy of the Edge. Now the Edge has posted a response to Dyson by Alun Anderson, editor-in-chief and publishing director of the New Scientist:

[In the Arctic Circle] you don't find so many people asking "what's all the fuss about global warming", as Freeman Dyson does in his recent controversial defence of "heretical" views of climate change on Edge. Climate change has arrived. Any Inuit hunter living in the nearby villages can tell you what they see…

… This is one of the regions of the world that will change first and fastest as a result of climate change. There will be losers but there may be winners too (on this I would agree with a heresy of Dyson)...

First and foremost, of course, we would like to know what to expect. And here I would agree, just for a moment, with half of another of Dyson's heresies. Our models of climate change do not entirely capture "the real world we live in". We do know that temperatures are rising faster in the Arctic than almost any other place and that the extent of the sea ice is shrinking with dramatic speed but our models aren't accurate. That said, Dyson is totally wrong with the second half of his criticism, that the climate experts end up believing their own imperfect models when they should "put on winter clothes and measure what is really happening".

Scientists are totally aware of the shortcomings of their models and up here in the Arctic they are gathering data with unprecedented energy. Now that International Polar year has begun, there are going to be more scientists up in the Arctic that at any time in history. They need that data to validate their models and satellite observations.…

Knowing that Arctic climate models are imperfect, it would be reassuring for me, if not for the scientists, to be able to write that scientists keep making grim predictions that just that don't come true. If that were so, we could follow Dyson's line that the models aren't so good and "the fuss is exaggerated". Scarily, the truth is the other way around. The ice is melting faster than the grimmest of the scientist's predictions, and the predictions keep getting grimmer…

…Still, I am excited by the prospect that there might be winners from climate change. The Arctic contains vast reserves of gas and oil (25% of the world's undeveloped hydrocarbons), minerals and even diamonds.

…. But there is still a lesson for the second of Dyson's declared big heresies, "the wet Sahara".

Climate change might actually bring the wetter climate of the Sahara of six thousand years ago back and Dyson argues that the "warm climate of six thousand years ago with the wet Sahara is to be preferred, and that increasing carbon dioxide in the atmosphere may help to bring it back". So we should believe that climate change may make life hard on some parts of the planet but open a new Eden elsewhere and we should not make a "fuss". The problem, of course, is that as the incipient signs of strife in the Arctic show, the planet's losers from climate change are hardly likely to make it to a new green land without a war.

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