All discussion threads eventually wander way off-topic if they are left to run long enough, and that’s certainly happened with my last post on the peppered moth controversy. At Crooked Timber, the debate was mainly about the role of experts and drifted into debate and meta-debate about Iraq and WMDs. On this blog, it’s got even odder, into a discussion of the well-known rightwing talking point “environmentalism is a religion”. A couple of links back to the original post have been missed though.
First up, it’s important to note that the “environmentalism is a religion” gambit is straight out of the creationist playbook. Creationists have long argued that evolution is not a scientific theory but part of a religion of “secular humanism”.
Second, the peppered moth controversy has an exact parallel in the global warming debate, the dispute over the hockey stick graph showing global temperatures at their warmest level for the past thousand years. As with the peppered moth
a striking, though minor, scientific finding, was used to illustrate a well-established scientific theory, and becomes the target of those opposed to the theory, and to science in general, for political or religious reasons. Minor errors in and procedural criticisms of the work supporting the finding are conflated into accusations of fraudulent conspiracy that are then used to attack the theory as a whole. Distorted versions of the whole story circulate around the parallel universe of antiscientific thinktanks, blogs and commentators, rapidly being taken as established fact.
Since it was first produced, the hockey stick finding has been repeatedly replicated, and supported by a study of the National Academy of Sciences. The remaining area of serious dispute concerns the degree of confidence in the reconstruction of medieval temperatures and the inference that the late 20th century was the warmest period in the last 1000 years. The IPCC Fourth Assessment Report calls this conclusion “likely” (66 to 90 per cent), while the National Academy of Sciences says “plausible” (around 66 per cent).
On the other side, the critics have followed the creationist strategy exactly, turning minor criticisms and quibbles into claims of fraud. They even held their own inquiry, set up by Republican Congressman Joe Barton, and run by statistician Edward Wegman. I had my say on Wegman’s silly attempt at social network analysis at the time.
If there was any remaining doubt about Wegman, it’s been removed by his signature on this open letter to UN Secretary-General Ban Ki Moon, which pushes an extreme delusionist point of view, including the claim that “there has been no net global warming since 1998”. As Tim Lambert points out, this is a disgraceful piece of cherrypicking, based on the fact that 1998 was an exceptionally warm El Nino year. Most of the signatories to the letter are sufficiently ignorant of statistics that they might not realise how ludicrous a claim this is, but Wegman has no such excuse . Clearly his statistical expertise goes out the window when he writes on this topic. And of course, any claim to independence he might have is shot to pieces now.
A mildly interesting fact about the letter is that while one of the leading hockey stick critics (Ross McKitrick) signed it, the other (Stephen McIntyre) did not. Maybe he wasn’t asked or doesn’t like open letters. But perhaps he realises that it is rather silly to hang your credibility on a claim which is unlikely to survive the next El Nino cycle.