The Bet

Scott Armstrong is a noted expert on long-range forecasting – he quite literally wrote the book on the subject. He's recently written a paper (available here, PDF) that examines the methods used by climate scientists to forecast global warming. I was struck by the way in which Armstrong attacks this from a method I wasn't familiar with: examining the forecasting methodology itself. Here is a snippet from the paper's conclusions:

Our paper is concerned with rational assessments of public policy, not with public opinions. People will continue to believe that serious manmade global warming exists as they will continue to believe other things that have no scientific support (e.g., the biblical creation story, astrology, minimum wages to help poor people, and so on), and public opinion can be intense on such issues. Public policy makers should, however, be concerned with how to move away from emotions and towards rational scientific analysis.

One might say that it is important to consider steps to prevent global warming, but we have the same level of confidence in saying that we should take steps to prevent global cooling. The more important question is “what is the best way to invest our resources for the benefit of mankind?” This would lead to such trade-offs as asking whether it is better to spend a dollar on reducing AIDS or air pollution or malaria or breast cancer, where we know what policies will work, or to spend it on controlling future climate, where uncertainty about the situation is high. Given the large uncertainties of climate change science, government polices on climate control are unwarranted and will reduce the well-being of the great majority of people who are not the beneficiaries of the wealth redistribution that will occur as a result of such policies. Advocates owe it to the people who would be affected by the policies they recommend to base their advocacy on scientific forecasts that address all four of the key areas that are necessary for a rational analysis of the problem. We hope that before committing resources, decision makers will insist on scientific forecasts rather than accept the opinions of some scientists.

In comments Armstrong has made to reporters, he makes an interesting point: that scientists aren't generally very good at making forecasts, even when they are experts in the science of the field. He makes the case – and he's eminently qualified to do so – that the data and skills needed for forecasting are completely different than those needed for the science. Fascinating stuff, and I recommend reading the entire paper (it's not very long).

To help publicize the paper, Armstrong has offered to bet Al Gore $10,000 that our climate will not change. More on the bet is available here and here. At this writing, the Goracle has not responded...