Friday, June 22, 2007

Wharton Professor bets Al Gore on Global Warming II

James Annan (climate scientist and betting man) has some comments on Prof. Armstrong's proposal to (possibly) soon to be Dr. Gore.

June 19
"This looks interesting:..."
"...On further digging, it seems like Armstrong is a common-or-garden variety delusionist, with his "audit of the IPCC forecasts of global average temperature" being little more than a laundry list of wrongheadedness, nonsequiturs and nitpicking, much of which isn't even remotely relevant ("For example, policy responses to Rachel Carlson’s Silent Spring, failed to anticipate that millions of people would die from malaria because efforts to reduce the use of DDT"). In fact he takes a particularly clueless tack with his summary:..."

June 20
At a glance, he is using the most obvious and trivial trick, that he appeared to have ruled out with his talk of forecasting climate change on this page. In fact, the terms of his challenge refer to forecasting annual mean temperatures at a handful of points, using raw model output. The trivial trick here is that of course the models do not directly represent local temperature (typical resolution is ~300km horizontally) and they also have significant regional biases, so meaningfully relating their output to local temperature requires at a minimum some sort of bias correction and/or downscaling. Such bias adjustment is an entirely routine procedure in many branches of forecasting, it is inconceivable that Armstrong does not realise this.

I think Mr. Annan likes the word delusionist.
"This proposal has attracted some interest, primarily it seems from the delusionist wing of the blogosphere (eg)."