James Hansen, head of the NASA Goddard Institute for Space Studies, offers this as a reason for scientists to decline public debates about climate change:
… public discussion of global warming is befogged by contrarians, whose opinions are given a megaphone by special interests that benefit by keeping the public confused. Some of the contrarians were once scientists, but now they behave, at least on the topic of global warming, as lawyers defending a client. Their aim is to present a case as effectively as possible, citing only evidence that supports their client, and making the story appear as favorable as possible to their client. The best, the most articulate, are sought out by special interests, and even by much of the media, because the media likes to have “balance” in its coverage of most topics – and especially this topic because special interests have influence on the media.
The barrage of e-mails that I have received from the public highlights another aspect of the global warming story: it is now very political. The people sending these messages are not generally scientists, even though in many cases they parrot “scientific” statements of contrarians. In their opinion these matters should be discussed in you-tube “debates” between scientists and contrarians. My guess is that scientists may not fare very well in such a format.