Who can comment on global warming?

Paul Newall of the Galilean Library has a great comment on doubt and disunity in science.  He raises a particularly interesting point on expertise:

If everyone has to possess specialist knowledge in order to be permitted to comment on a scientific theory, and if science has become so deeply specialised that even scientists in the same discipline can barely speak to one another, then perhaps no one can really comment on anything? In particular, interdisciplinary projects like the IPCC could never work…I will come back to this but the question remains: is this the kind of science – and political discussion of science – we really want?

Hyperspecialization may not be a good thing and may in fact corrode public discourse.  That topic is several blog posts in and of itself (check out this Facebook thread for diverse perspectives.)  But right now it is an incontrovertible fact that we must account for.  Consider recent PhD theses from my  former research group.   I can assure you that people involved in hardware design aren’t familiar with the details of space plasmas and vice versa.  Whether or not we ultimately want this environment, it does exist already.  So if “comment” means speaking authoritatively, I think we’ve already reached the point where “no one can really comment on anything.”

Given this state of affairs, I subscribe to a rather extreme epistemic modesty.  I believe that only the IPCC should be trusted with regards to anthropogenic climate change (ACC).  As  I’ve argued before, this approach sharply contrasts with the current situation.  We all use the words “science” and “scientists” as if they’re coherent concepts.  But I don’t think it is.  A single word cannot describe an enterprise that involves hundreds of billions of dollars and several million people in the U.S. alone.  It’s similar to talking about athletes without recognizing the immense differences among swimmers, runners, and football players.