I get tired writing about global warming (read: anthropogenic climate change). As far as I am concerned, the main conclusions are settled. The main conclusions that I’m talking about is the mainstream consensus outlined by the IPCC and supported by every major academy of science in the world and virtually every scientist publishing research on the matter. The consensus is that human activity is responsible for recent climate change, that this climate change has adverse effects, and that the effects are going to worsen if we continue down the “business as usual” path. That’s settled, no question about it. I would like to leave the quibbling over minor uncertainties, model improvements, and further refinement of the theory to the more capable scientists who publish legitimate research in the technical literature. I find myself, however, having to defend against the main conclusions of the theory of anthropogenic climate change, because people find opportunity to attack it whenever it becomes politically convenient. That’s essentially what we call partisanship (i.e. hackery). These people like to pretend they are engaging in some sort of scientific inquiry, so label themselves “skeptics.” But we know this is not true—the real skeptics (e.g. Lindzen) are few and far between—so I label them “septics,” borrowing the term from William Connolley, who explains the meaning on his blog.

Again, we find the septics at the SCSU Scholars blog making a bunch of ado, in their regular fashion. But about what? Essentially, nothing. Dr. Banaian, professor and chairman of the economics department at SCSU, using a satirist’s Web site for reference (though, be careful in pointing out the fact, or you’ll be accused of ad hominems), complains about the use of principal components analysis (PCA)—a statistical procedure used in the analysis of data—in a 1998 paper written by Michael E. Mann, Raymond S. Bradley, and Malcolm K. Hughes (hereafter referred to as Mann et al.). The problem for Dr. Banaian lies in the fact that, as he explains it, “PCA is a technique that, in the social sciences, has been found to be highly sensitive to the inclusions of new proxies.” This might be true, in part, he says, in the natural sciences, but he’s not really sure, probably, in part, because he hasn’t read about it. That might be a wild supposition, but given that the professor even admits to us that he hasn’t even bothered to read the paper he criticizes, it’s not beyond legitimate possibility. This, he says, “increases my skepticism,” though “septicism” probably would have been more fitting.

I try to point out to the professor that the Mann et al. paper, the basic conclusion of which is that contemporary warming is anomalous (differing from previous warming), is valid and supported by virtually the entire scientific community that’s spoken on the issue, including those scientists who have published criticisms of the Mann et al. paper. Dr. Banaian says Mann et al. are wrong, I say they are correct. I better provide some evidence, right? One might reasonably make that assumption, so I link to a report done by the National Academies of Science (NAS), which concluded, “The basic conclusion of Mann et al. (1998, 1999) … that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years … has subsequently been supported by an array of evidence …” Summarizing the report, Nature, the prestigious scientific journal, writes that the the NAS “affirms [the] hockey-stick graph,” while Roger A. Pielke, Jr., a critic and pretty close to being a skeptic himself, writes, “the NAS has rendered a near-complete vindication for the work of Mann et al.” In addition to the NAS report, I linked to two peer-reviewed articles that support Mann et al.‘s use of PCA and the accuracy of their reconstruction of past temperature. The first paper, by Wahl and Amman (2007), is a response to McIntyre (who Dr. Banaian later appeals to) and McKitrick. Wahl and Ammann say, “the Mann et al. reconstruction is robust against the proxy-based criticisms addressed. In particular, reconstructed hemispheric temperatures are demonstrated to be largely unaffected by the use or non-use of PCs to summarize proxy evidence from the data-rich North American region.” Moreover, I provide a link to a blog post written by climate scientists discussing McIntyre and McKitrick (the people the aforementioned satirists relies on) and the various “false claims” they make regarding Mann et al.‘s use of PCA.

Well, one might think this is all well and good. Science, after all, is an objective field in which one can appeal to evidence, and the evidence can be judged on its merits. If someone has a differing point of view, they can provide the scientific evidence to support it. So it would be reasonable to assume that evidence should be welcomed when there’s a contradictory claim. It helps you evaluate the claims being made. But it’s dangerous not to drink the Kool-Aid. The cost of not jumping on the politically-convenient (but scientifically-bankrupt) bandwagon of the septics is that I get derided for posting “a link dump”—because contradictory evidence isn’t welcome. Instead it constitutes “linking dumping” to “the cross-referencing, daisy-chain-refereeing bunch from the Mann gang.” I never link to Mann nor anyone from his “gang,” but these types of facts are not supposed to matter. (Although, even if I had linked to Rutherford et al., which includes Mann, and the defense they provide for the methods used in the Mann et al. paper, so what?) I ordinarily would not think much of this; it’s the typical rhetoric the septic retches up whenever confronted by an “inconvenient truth” (science). The thing is, you don’t typically see the type of anti-intellectualism displayed among self-professed scholars. The septics I usually speak with on a near-daily basis, though their rhetoric is virtually identical, don’t usually come from academia. Perhaps that says something. But when you get accused of being a “pedant” trying to enter “Valhalla,” I think this says something quite serious about the culture of this so-called “skepticism,” which has always had at its roots a derision of science and an acceptance anti-intellectualism. I personally find it to be pretty dangerous.

But let’s say we ignore the rhetoric and accept Dr. Banaian’s argument. Does it mean anything? It means nothing. We’re talking about a 1998 paper that has been updated by the authors and commented on multiple occasions over the years, and further supplemented by numerous, independent research that has all come to the same basic conclusions that Mann et al. came to in their paper. Any suggestion that the Mann et al. paper is crucially relied on to support the basic conclusions made by the IPCC or even that contemporary warming is anomalous is transparently absurd. So even if Mann et al.‘s paper was invalid (though it wasn’t), it says nothing about our understanding of climate reproduction or contemporary warming. The so-called “hockey stick” graph that appears in the Mann et al. paper is but one of many “hockey sticks” that exist in the literature on climate reconstruction. See, for example, this image put together by Robert Rhode; a similar image is found in the IPCC’s latest report (Chp. 6 of the WGI contribution) and elsewhere. Mann et al.’s (1999) graph is the plain blue line in Rhode’s image.

The literature on the issue is robust. Contemporary warming is anomalous—unprecedented within the past 1,000 years. The cause is explained by the theory of anthropogenic climate change. We can and should dismiss the feverish rhetoric as ado about absolutely nothing.