Mann v. Hansen: They Aren't All the Same

My interest in the global warming controversy centers mostly on the question, largely although not entirely economic, of what the net effect for humans would be of global warming on the scale suggested by past IPCC projections; for details see my previous posts on the subject. I have, however, also been an observer, mostly from a safe distance, of the ongoing war between proponents of the conventional view of global warming and critics. For anyone else interested in observing it, I suggest the RealClimate blog for the former side and Anthony Watt's What's Up With That for the latter. They represent the more reasonable range of their respective factions. For the less reasonable range, a sample of both sides can be found on the Usenet group alt.global-warming.

One not surprising feature of the argument is that each side tends to demonize everyone on the other side. That is a mistake. Some people hold a position for good reasons, some for bad. Some supporters of a position are honest, some are not. And that is true both of correct positions and of incorrect ones, given that most such disputes are over questions complicated enough so that there are good arguments for both sides.

I was reminded of this point by a recent link on WUWT to a paper coauthored by James Hansen, who has been a prominent supporter of the idea that global warming is a very serious problem and strong measures should be taken to deal with it. The paper is a defense of nuclear energy, both on the grounds that it results in many fewer deaths than conventional energy sources and on the grounds that it does not produce CO2, hence shifting to nuclear energy would reduce global warming.

That is interesting because, while the second point is clearly true and the first may well be, it is not a position popular with environmentalists. I pointed that out in an old post on this blog, and ended with:

I am sure there are people who are both seriously worried about global warming and in favor of nuclear power. But how many of them are there? How many high profile spokesmen or organizations have taken that position?

 I now have at least one example.

This is the second time I have noticed Hansen getting something right. The first was a video of a talk he gave on how to control global warming. It was in favor of what economists call a pigouvian tax, in this case a tax on putting CO2 in the air, as a superior alternative to more direct forms of regulation. Given his underlying assumption—that global warming produces large net negative externalities—he had the economics right. In that case as well, although not as clearly, he was going against the consensus of "his side," most of whose members, in my experience, support a range of more direct regulations and many of whom disapprove of the idea of allowing firms to "buy the right to pollute."

I offer, as a contrast to Hansen, another prominent figure on the same side of the dispute, Michael Mann, most famous for his role in the hockey stick controversy, the argument over whether features of a graph of global temperature in an article he co-authored were real or were artifacts of an error in the statistical procedure he used to produce it. That particular controversy is complicated enough so that I have no strong opinion on it, although I do have the opinion of one statistician I know that there was a real problem with the analysis. 

But I also observed, mostly via arguments on the Usenet group, a less important controversy over a simpler issue, the claim by Mann, his university, and his supporters, that he was a "Nobel winning scientist."

[Later addition: Tim Lambert in the comments points out that the university web page claimed Mann won a Nobel prize (along with others), but specifies the peace prize, hence does not describe him as a "Nobel winning scientist."  The claim on Mann's facebook page was similar. 

So I don't have evidence that Mann or the university described him as a "Nobel winning scientist," merely that they (falsely) claimed he had won a Nobel prize. On the other hand, a quick google finds lots of stories by supporters, including stories of interviews with Mann, which do describe him as a "Nobel winning scientist," which seems unlikely if he made any effort to correct those who so described him.]

That claim was bogus twice over. To begin with, the Nobel prize in question was the Peace Prize, so even if Mann had won it, the description, although literally true, would be misleading. But in fact, the prize did not go to him, it went to the IPCC. His claim was based on a certificate from the IPCC, sent to a substantial number of people, crediting them with work that helped the organization win the prize. 

Doing work, along with others, that helps an organization win the Peace Prize does not make you a Nobel prize winning scientist, as should have been obvious to anyone not blindly partisan—but wasn't to a considerable number of people who were. Mann's university, many of his supporters, and (I think) Mann himself, finally abandoned the claim after someone got in touch with the Nobel committee and got the response that the prize had been given to the IPCC, not to Mann et. al., and he was thus not a Nobel winner. That does not tell me whether the hockey stick is or isn't bogus, but it does tell me something about Mann that makes me very reluctant to trust anything he writes.

I could, I suppose, make longer lists of good guys and bad guys on both sides of this and other controversies—Pachauri, the head of the IPCC, would be on the same list as Mann, for his role in the Himalayan glacier controversy. So would some people on my side of other issues. But I think two examples are sufficient to make the point.