I’ll respond yet again to Paul Newall at the Galilean Library. Paul asks: “What, then, is the difference between someone who seizes on doubts to develop a new theory and someone who is merely a contrarian or else actively opposes a theory because of its perceived consequences?”
If by “perceived consequences” we mean the standard solutions offered for climate change (cap-and-trade, carbon tax, efficiency standards, etc.), then we’ve made an implicit and somewhat problematic assumption here. We’ve assumed, as does everyone else in this debate, that everything hinges on the presence or absence of scientific doubt. On one hand, environmentalists insist that cap-and-trade inevitably follows from sound science. Denialists argue that doubtful science undermines any possible action. It’s important to note that both sides make essentially identical arguments by placing science at the center of the decision-making. They simply conceptualize the science differently.
What’s missing is the idea that climate change manifests different types and degrees of doubt that aren’t necessarily coupled. There’s very little doubt over the basic concept of anthropogenic climate change (ACC), somewhat more doubt over the climate sensitivity, and a high degree of doubt about economic projections and the rate of technological innovation. These questions accompany another layer of doubt about the appropriate policy response. There’s significant doubt about the effectiveness of cap-and-trade and carbon tax, doubt about the use of offsets, and even doubt whether we should respond at all.
As Dan Sarewitz and Roger Pielke Jr have argued repeatedly, eliminating doubt in the first set of issues doesn’t help us move forward on the second. Improved global climate models will not automatically bring us intelligent climate policy. Some would even say that focusing on them distracts from us from more important problem.
I know I haven’t at all responded to Paul’s question. But perhaps his question would never be asked if we confronted and decoupled the many dimensions of doubt that climate change presents us. It should be possible to reject any action on climate change even if you agree with the IPCC. As I’ve just said, wait-and-see may be a perfectly rational response. While this approach will surely not end debate, at the very least it might undermine the need to emphasize and distort scientific doubt.
Just to clarify, I gave an answer to my own question in the form of a values-based demarcation criterion. I’m not sure that it works all the time but it would take into account the disunity involved in both ACC and ACC-skepticism. As you note, it’s not clear why eliminating doubt will bring about unity regarding what action to take, but I also wonder if arguing for unity and (near-)certainty doesn’t do rhetorical damage to the possibility of better dialogue in future about science and policy decisions.