Gary Gutting, a philosophy professor at Notre Dame, offers a pretty rock-solid argument that I recommend to our resident AGW denier: On Experts and Global Warming.
How can we, nonexperts, take account of expert opinion when it is relevant to decisions about public policy?
To answer this question, we need to reflect on the logic of appeals to the authority of experts. First of all, such appeals require a decision about who the experts on a given topic are. Until there is agreement about this, expert opinion can have no persuasive role in our discussions. Another requirement is that there be a consensus among the experts about points relevant to our discussion. Precisely because we are not experts, we are in no position to adjudicate disputes among those who are. Finally, given a consensus on a claim among recognized experts, we nonexperts have no basis for rejecting the truth of the claim.
There’s really no way I can see around his logic. I’m sure shcb will find a way, but I think that’s more a testimony to the power of motivated reasoning and the plasticity of shcb’s reality than it is to the merits of Gutting’s argument.