WARM TIMES NEED COOL HEADS

by
PETER FELDSTEIN

_________

Peter Feldstein, a Montreal-based translator who has observed the climate change debate for over a decade, takes major issue with David Solway's contention that global warming is not man made.

Heat is in proportion
to the want of true knowledge.
Laurence Sterne

In his article “Global Warning” (Arts and Opinion, Vol. 7, No. 3, 2008), Canadian poet David Solway denies that the present episode of global warming is largely caused by human activity. He opines, “the scientific consensus today is slowly beginning to shift away from the catastrophism of Gore, Suzuki and the United Nations IPCC’s Fourth Assessment Report, to suggest that the human contribution to global warming is far less than originally assumed and that a meteorological calamity is highly unlikely.” I contend that this is a perfectly testable proposition that he has not bothered to test. Quite simply, he is wrong, and it is my duty to the readers of Arts and Opinion to point it out. The scientific consensus around the crucial aspects of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) remains as robust as ever. Not total -- just, shall we say, something shy of overwhelming.

What that consensus says, as a great many of us know, is that today’s episode of global warming is “very likely” (i.e., with 90% probability) due to human emissions of carbon dioxide and other greenhouse gases. The IPCC has determined that our current levels of emissions put us on track for an atmosphere that is 1.4–5.8 °C warmer by the end of this century. To put this in perspective, at 1.4 °C, we lose the coral reefs of the Indian Ocean. At 2 °C, many unstoppable feedbacks are expected to kick in and it may no longer be possible to prevent runaway climate change. At 5.8 °C, if the comparable warming during the great Permian extinctions is any guide, a large percentage of present life forms disappear forever. To avert a global rise on the order of 2 °C--– to avert those deadly feedbacks and keep the future livable -- global human emissions must be decreased by 60% over the next several decades. We must act quickly if we want our grandchildren to enjoy a semblance of the climate we take for granted.

To understand what a Herculean task Solway has given himself -- the task of showing that the scientific consensus on global warming is being deserted -- one has to understand both the nature of the edifice that he attacks and the process by which science is done and revised in the present day.

The IPCC was established in 1988 by the World Meteorological Organization with a mandate to review the scientific literature on global warming and assess the likeliest outcomes of our current carbon-intensive path. The body of assessment it has produced covers the work of 2,500 researchers and is probably the largest such scientific endeavour in history. For this effort, it shared the 2007 Nobel Peace Prize with Al Gore. Most climate scientists consider its series of assessment reports to represent the state of the science on global warming because they are derived from a painstaking analysis of numerous independent lines of evidence, all converging on the same conclusions.

It is indeed a towering consensual edifice, but there is nothing wrong with Solway’s attempting to topple it. To do so, though, he has to put forward a group of peer-reviewed studies showing that there is something critical the IPCC missed or misinterpreted. Peer review is the process whereby a paper submitted to a journal is reviewed by a committee of experts in the discipline prior to publication. The reviewers make sure that the paper makes no egregious errors of basic understanding and takes account of other peer-reviewed findings that could alter its conclusions. The fact that a paper gets through the process does not, of course, make it correct; it merely makes it a piece of work that scientists have to pay attention to. The status of peer review as the standard to meet is disputed by almost nobody in the natural sciences, regardless of where they stand on global warming. It is the statute on which the collegial court of scientific opinion is built.

Now, the chances of Solway finding this untapped body of contrarian work, this sizeable group of peer-reviewed deserters, are mighty slim. Since the mandate of the IPCC is to assess every such paper relevant to climate change, it is hard to imagine what they could be missing. But we don’t need to rely on deductive reasoning: Naomi Oreskes, a professor of history and science studies at the University of California-San Diego, read each of the 928 peer-reviewed studies containing the phrase “global climate change” that were published from 1993 to 2003 and concluded that not one of them -- that’s right, none -- disagreed with the IPCC’s consensus position on human-caused global warming. Her somewhat restrictive keyword search probably excluded a few contrarian papers, and others may have appeared since then. Nevertheless, no one has impugned her overall conclusion that these papers are very, very scarce.

But Solway’s article is over 5,000 words long, you may be thinking. There must be some substantive kernel in there that has got him worked up. It can’t just be a mess of unsupported put-downs such as: “The IPCC, which certified and entrenched the so-called ‘scientific consensus,’ is essentially a political body with an agenda of its own.” My appraisal, after diligently sifting through and categorizing every single one of his references, is that he appears to grasp the importance of peer review, for he uses the term once, but that in all those 5,000 words of copy he cites exactly one qualifying study that explicitly casts doubt on the IPCC consensus. Being generous, one could also include his citation of a letter in Science by a group of Swedish authors (letters are not peer-reviewed in the standard sense but rather editorially selected for publication) which, he maintains, “places the emphasis elsewhere” than on human causation of the climate crisis. These two papers, I argue, constitute his entire case that the consensus is “beginning to shift away” from the IPCC’s conclusions.

How in the warming world a total of two papers adds up to a “shift away” in Solway’s mind, I do not profess to know. But before I rest my case, it is worth dwelling on these two purported pieces of evidence, since his use of them is typical of certain rhetorical strategies current among climate contrarians. The letter is easy to dispense with: It turns out that it supports the IPCC’s position, not Solway’s. He writes:

a study [the letter] . . . co-authored by Rune Graversen [et al.], while not categorically ruling out human intervention in climate warming, places the emphasis elsewhere. In attempting to explain the phenomenon known as “Arctic amplification,” the study cites “changes in oceanic atmospheric circulation” as one of the main drivers of observed temperature increases in the high North.

Why, I wondered as I read this passage, should “changes in oceanic atmospheric circulation” be incompatible with the IPCC’s consensus statement? Couldn’t these changes be the result of human greenhouse gas emissions (in climate science terms, a “feedback” rather than a “forcing”)? Does the letter really “place the emphasis elsewhere”? I decided to ask Dr. Graversen himself and I wrote to him as follows:

The structure of [Solway’s] citation, in my educated layman’s estimation, misleadingly suggests that your letter represents a challenge to the IPCC consensus on anthropogenic [human-caused] global warming when in fact it does not. Could you kindly assist in determining whether this is the case?

Dr. Graversen wrote back almost immediately:

You are completely right, the reference is misleading. Our letter does not challenge the general consensus of the scientific community expressed in the latest IPCC report that most of the global warming is very likely due to human emissions of greenhouse gases. (In fact, we phrase this consensus in beginning [sic] of paragraph two in the letter).

. . . Arctic amplification is in agreement with theories of global warming. I’m not aware of any state-of-the-art climate model which does not show Arctic amplification when it is forced by increasing the atmospheric greenhouse gas concentrations.

Clearly, Solway must have nodded off after reading the first paragraph of the Graversen paper, or he would have seen that it is of no use to his argument. But his implication that it could pose a serious challenge to global warming theory, when it does nothing of the kind, is an all too common feint among climate skeptics.

As to the study, by Douglass et al., and a 2004 predecessor by some of the same authors, these papers relate to a discrepancy between the predictions of greenhouse models on the one hand, and radiosonde observations of tropical tropospheric temperatures on the other. Basic thermodynamics and the greenhouse models predict that the upper troposphere in the tropics should warm faster than the surface, but the data is out of line with the predictions. The authors contend that the data is right and the models are faulty. If so, this would not refute the existence of human-caused global warming: the troposphere should warm no matter what the cause of warming at the surface. But it would spell trouble for the models, implying the need for a great deal of caution in interpreting their temperature predictions.

However, at least four published papers ignored by Solway take issue with Douglass’s work. They have found that the structural uncertainty of the radiosonde data suggests that it is probably the data, and not the models, that need refinement. One of these authors argues, “The new analysis adds to the growing body of evidence suggesting that these discrepancies are most likely the result of inaccuracies in the observed temperature record . . . ”

Not being a climate scientist myself, I am not qualified to rule on the contentions of either side. I can’t comment on Douglass’s rejection of “the proposition that greenhouse model simulations and trend observations can be reconciled.” But neither is Solway qualified to assert that this conclusion is “as authoritative as it gets.” That’s the kind of superlative non-scientists use to score a rhetorical point even though, in doing so, they betray their fundamental misunderstanding of scientific collegiality. Suffice it to say that the controversy is highly technical and not easily parsed by a layman. If you feel inclined to wade into it, prepare yourself with a solid comprehension of climate concepts such as the moist-adiabatic lapse rate, vertical wind shear, and the Madden-Julian oscillation. Get to grips with measurement uncertainty, the importance of timescale, and other statistical factors. And don’t be put off by a welter of acronyms -- MSU 2LT, UAH, RAOBCORE, and ENSO, for a partial list. It’s doable; I’m starting to get a handle on the topic myself. But it isn’t easy. Does Solway know what these terms mean? Can he be relied on to use them appropriately? He didn’t do so well with “Arctic amplification.”

And so we come face to face with another standard tactic of the climate contrarians: Sing the praises of a single study, insist that it has brought the whole scientific edifice crashing down, ignore contrary considerations and hope no one looks too closely. If these are the best exhibits Solway can come up with to assail the scientific consensus, then I submit that the consensus has escaped unscathed. Naturally, I would be happy to look at any further evidence he wishes to present; my only criteria are i) peer review and ii) dispassionate, hype-free analysis.

For the reasons explained above, I have deliberately dwelled on these two citations to the exclusion of much else in Solway’s article. He should be thankful, for his credibility as a commentator on the IPCC consensus is compromised to an even greater degree by his propensity to surround these few valid citations with a great quantity of fallacies and irrelevancies taken from sources that carry zero scientific weight. In support of his claim that human beings do not cause global warming, he cites the blog of James Inhofe, the Republican senator from Oklahoma who has no scientific credentials and, reportedly, a larger amount in oil industry campaign contributions than almost any other American politician. He adduces a petition signed by such august climate scientists as “Michael J. Fox,” “John C. Grisham,” and Spice Girl “Geri Halliwell.” He cites the tabloid London Express and Rev. Sun Myung-Moon’s Washington Times. And he quotes a carbon consultant (David Evans), an agricultural economist (Holly Fretwell), a statistician (Bjorn Lomborg), a Thatcherite policy advisor (Christopher Monckton), a coal engineer (Vincent Gray) and the founder of the Weather Channel. None of these people, to my knowledge, has ever published a peer-reviewed line in the field of climate change. Their opinions on the subject are worthless -- or, to put it more charitably, they are worth no more than yours, mine, or Solway’s.

These sources are marshaled to support a smattering of equally worthless and discredited claims that are easy pickings even for a layman. Consider, for example, Solway’s opening argument, a minor classic in denialist circles: “Mars is also warming at present,” he writes, “though it seems there are no SUVs chugging along the planet’s surface . . . ” The simultaneous warming on Earth and Mars couldn’t be a coincidence-- could it? -- so it must be caused by the only thing the two planets have in common: the sun. There’s just one problem: solar irradiance isn’t increasing now and hasn’t been for half a century. Furthermore, we have very little evidence that Mars is warming globally, only at its South Polar Cap, and that over only a few years. Mars specialists think this is due to the topography at the pole, and that it is a completely independent phenomenon from what is happening on earth. Ironically, if similar evidence were put forward as the sole proof that the earth is warming, the skeptics would rightly laugh it out of court.

Or consider his next stop, the erstwhile scientific dalliance with global cooling. He writes, referencing the New York Times and something called the “Global Ecology network”: “And not so long ago, we might recall, we were all getting ready to freeze . . . ” Perhaps, but mostly because of scaremongering from the popular media and other unqualified commentators. It is a myth put about by certain right-wing websites that 1970s scientists were wringing their hands in unison over the prospect of global cooling. On the contrary, they did a remarkably evenhanded job of expressing the uncertainty that has always gone along, then as now, with climate predictions. In only one or two cases did a paper go out on a limb and predict that an Ice Age was imminent. The US National Academy of Sciences wrote in 1975, summarizing the state of knowledge at that time, “we do not have a good quantitative understanding of our climate machine and what determines its course. Without the fundamental understanding, it does not seem possible to predict climate.”

I could continue, but instead I refer you to websites such as realclimate.org and scienceblogs.com/illconsidered, where many similar canards are catalogued and debunked. In truth there is little point in going on, as Solway does not evince much of an attention span for science anyway. He veritably scurries to his conclusion -- relax, folks, the sky’s not falling -- apparently anxious to switch gears and devote the rest of his piece, more than half of it, to a diatribe against worshipers of “Gaia,” the “false god.” He doesn’t just call global warming theorists Chicken Littles and leave it at that; no, his agenda is lofty moral warfare, a crusade against earth lovers generally and the degraded ethos they embody. Environmentalists, he tells us, are suicide cultists, godless acolytes, nutcases, and fascists. Oh, and we’re also lousy poets!

The whole exercise resembles a quixotic dash across a perceived battlefield of science, with our hero nervously jabbing at imagined enemies and racking up imaginary points. Hah! They predicted cooling back in 1975! Take that! Safe in the shrubbery, peering out at the battlefield that is actually a field of windmills, he declares victory and is free to wax indignant about the godless religion of environmentalism and its “high priests,” Al Gore and David Suzuki. In just the same way Don Quixote, the illustrious hidalgo of La Mancha, created a mental world of his own in which to wax elegiac about the splendid but fictitious Amadis of Gaul, that most gallant of the knights-errant. And to think that instead of tilting at windmills, Solway could be building them!

In the end he must face it: The reality of science is not the stuff of swashbuckling romance. It proceeds in workaday fashion by the steady accumulation of observations about the real world, which must be continually subjected to the sort of cool-headed, meticulous analysis at which Solway has thus far proved inept. If he wants to unseat the scientific consensus and show that global warming is caused by a hitherto undetected natural phenomenon, or by environmentalists spewing hot air, he would do well to start by correcting this elementary misapprehension.