So much ado, but about what? Thursday, Jan 14 2010 

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.

Advertisements

Michelle Bachmann, Chris Horner, and Alfred Pekarek, oh my! Thursday, Apr 9 2009 

Today, Congresswoman Michelle Bachmann paid a visit to SCSU. She represents (in one way, at least) Minnesota’s Sixth Congressional District, which includes St. Cloud. Her ridiculous and frankly embarrassing statements made time again in public don’t really merit repeating here. Instead, I want to focus mostly on the claims that Chris Horner made today, presenting his case against cap and trade and the scientific consensus on global warming. He was brought along as a speaker by Congresswoman Bachmann, because she was so impressed with his rhetoric that he displayed in Washington a few weeks ago. Congresswoman Bachmann didn’t have much to say, except for some prepared remarks that were brief.

So, who then is Horner? He is an attorney and fellow at the Competitive Enterprise Institute, a conservative think tank. He’s written a few partisan books, talked a lot, etc. There was also Alfred Pekarek, an SCSU assistant professor in the Earth and Atmospheric Sciences department who studies mostly rocks. But he’s an ardent global warming denier who has happened to write some nonsense for the AAPG. (The AAPG, in 2007, became the last major scientific organization to affirm human’s role in global warming, after falling out of line with the scientists who work with them.) Of course, Dr. Pekarek has published no peer-reviewed scientific papers on the subject, but he was mostly there as a figurehead anyway. Horner did all the talking. So what did Horner have to say?

The topic of the discussion was cap and trade, whereby the government sets a cap for carbon emissions and companies are given allowances for polluting so much. If you fall below this limit, you can trade (sell) your allowances to other companies that don’t meet this limit. The idea is that the free market will take over and corporations will stop polluting the air. Quite frankly, I don’t care for cap and trade, and I think it’s a stupid idea. It doesn’t work and so emissions don’t go down. That automatically eliminates it as any solution. This was part of Horner’s argument too, but mostly he was worried about it being anti-competitive, against the consumer, big interests, etc. That’s all well and fine, I don’t care to debate him on that issue since it doesn’t interest me (I’ve already stated it’s not a solution).

However, in what could be called the second part of his presentation, which was nominally called a question-and-answer session, Horner went on about the perceived lies in the global warming debate, though it isn’t much of a debate anymore. Horner really focused on three main things in his drivel, which, by now, has become old, tired, and thoroughly refuted: The IPCC sham, historical temperature record, and the relationship between solar forcing and temperature.

Horner took issue with the claim that the Intergovernmental Panel on Climate Change (IPCC) is made up of over 2,000 scientists who author their authoritative assessment reports. But the IPCC only claims to have 450 lead authors, not over 2,000, and 800 contributing authors. Furthermore, they release four reports (one of which is a synthesis of the other three). Only one deals with the actual physical basis for global warming, which is the Working Group I report. The IPCC claims this report was made by some 600 authors (lead and contributing) and reviewed by over “620 expert reviewers.” In its annex (PDF) they list all of their authors and their reviewers for that report. Wikipedia will actually make it easier for you, as it has a list of the contributors and their roles. Overwhelmingly these contributors come from the field of climatology or atmospheric sciences. That’s certainly a lot more than the Oregon Petition can say. (Never mind that every major national science academy in the world accepts the IPCC’s conclusions as the consensus on global warming.)

One thing Horner could not stop repeating is that in the historical temperature record, temperatures led CO2 emissions. What this means is that the the Earth saw a temperature increase before there was a CO2 increase (so temperature drove CO2 to go up, not the other way around), which Horner then construed to mean that CO2 could not be possibly be causing the current global warming. Well, of course, Horner is dead wrong. It is true that in the historical temperature record going back 600,000 years, CO2 lags behind temperature increases by about 200 to 1,000 years. This is because temperature increases cause increases in CO2, and this CO2 in turn causes a temperature increase (this is called a positive feedback in the technical literature). And we actually have a pretty good understanding of what caused these temperature to go up, which is something called orbital forcings, meaning small changes in the Earth’s orbit (Milankovitch cycles) change how much sunlight hits the planet, one of the reasons for ice ages and glaciations. This increased the CO2 in the atmosphere (by mechanisms I don’t care to go in detail about here), and after a certain period of time the CO2 took over as the main contributor to the temperature increases. (That is, temperature increased for some 5,000 years, only during 800 or so of which temperature led CO2; CO2 caused the other 4,200 years of warming.) That’s what the ice core record shows. So it’s very clear, still, that CO2 is a greenhouse gas that causes temperature to go up. The climate record shows this. But it’s also elementary physics and chemistry. The radiative properties of CO2 have been known for over 100 years. That there was a lag in the historical record in no way contradicts our understanding of how CO2 affects temperature, and it is this understanding that we use to explain the current global warming. For the sake of brevity, this post by RealClimate explains quite well the relationship between human activity and CO2 increases, and how it’s causing current global warming.

Finally, Horner points to the Sun as the main contributor to global warming. He says the Sun’s output matches quite well with variations in temperature. Again, this is flatly incorrect. A 2006 paper published in Nature by Foukal et al. showed that the Sun’s brightness has not increased over the past 1,000 years and that it has, in fact, contributed very little to the current global warming. When you look at recent solar variation, it doesn’t even come close to fitting the temperature record. The most liberal numbers, by Scafetta and West, suggest the Sun has contributed some 45 to 50 percent of the temperature increase between 1900 and 2000, and only 25 to 30 percent between 1980 and 2000. Likewise, the IPCC has found that the Sun slightly contributed to the increase in temperature between 1750 and 1950, but little after that. So when you take the Sun out of the equation, you simply cannot explain current warming.

Horner did address several other points, but this post is already getting quite long. I’d be glad to address them some other time. Suffice it say Horner is way off base with the scientific community, as are Congresswoman Bachmann and Dr. Pekarek. Instead, they wish to politicize the issue so they can propagandize and use all sort of rhetoric to win over gullible partisans. What we should do is focus on the science, and the peer-reviewed published literature is unequivocal on it stance on anthropogenic global warming.