Krugman v. Levin on Climate Change
Jim Manzi, a conservative expert on climate change, recently reviewed Mark Levin’s coverage of the subject in his book Liberty and Tyranny. Mr. Manzi was unimpressed:
I’m not expert on many topics the book addresses, so I flipped to its treatment of a subject that I’ve spent some time studying – global warming – in order to see how it treated a controversy for which I’m at least familiar with the various viewpoints and some of the technical detail.
It was awful. It was so bad that it was like the proverbial clock that chimes 13 times – not only is it obviously wrong, but it is so wrong that it leads you to question every other piece of information it has ever provided.
Levin argues that human-caused global warming is nothing to worry about, and merely an excuse for the Enviro-Statist (capitalization in the original) to seize more power. It reads like a bunch of pasted-together quotes and stories based on some quick Google searches by somebody who knows very little about the topic, and can’t be bothered to learn. After pages devoted to talking about prior global cooling fears, and some ridiculous or cynical comments by advocates for emissions restrictions (and one quote from Richard Lindzen, a very serious climate scientist who disputes the estimated magnitude of the greenhouse effect, but not its existence), he gets to the key question on page 184 (eBook edition):
[D]oes carbon dioxide actually affect temperature levels?
Levin does not attempt to answer this question by making a fundamental argument that proceeds from evidence available for common inspection through a defined line of logic to a scientific view. Instead, he argues from authority by citing experts who believe that the answer to this question is pretty much ‘no’. Who are they? – An associate professor of astrophysics, a geologist and an astronaut.
But he says that these are just examples:
There are so many experts who reject the notion of man-made global warming and the historical claims about carbon dioxide they are too numerous to list here.
He goes on to cite a petition “rejecting the theory of human-caused global warming” sponsored by the Oregon Institute of Science and Medicine and signed by more than 31,000 scientists. There are a few problems with this survey that Levin doesn’t mention. More than 20,000 of these “scientists” lack PhDs in any field. There was very little quality control: At least one person signed it as Spice Girl Geri Halliwell. Scientific American did the hard work of actually contacting a sample of individual signatories, and estimated that there are about 200 climate scientists who agree with the statement in the petition among the signatories. And most important by far, the text of the petition is not close to Levin’s claim of rejecting the notion of man-made global warming. In the key sentence it says that signatories do not believe that there is compelling scientific evidence that human release of greenhouse gases will cause catastrophic heating and disruption of the earth’s climate. Depending on the definition of “catastrophic”, I could agree to that. Yet I don’t reject the notion of man-made global warming.
On one side of the scale of Levin’s argument from authority, then, we have three scientists speaking outside their areas of central expertise, plus a dodgy petition. What’s on the other side of the scale that Levin doesn’t mention to his readers?
Among the organizations that don’t reject the notion of man-made global warming are: the U.S. National Academy of Sciences; The Royal Society; the national science academies of Australia, Belgium, Brazil, Canada, China, France, Germany, Ireland, Italy, India, Japan, Mexico, New Zealand. Russia, South Africa and Sweden; the U.S. National Research Council; the American Association for the Advancement of Science; the American Chemical Society; the American Physical Society; the American Geophysical Union; and the World Meteorological Organization. That is, Levin’s argument from authority is empty.
Of course, this roll call could be arbitrarily long and illustrious, and that does not make them right. Groupthink or corruption is always possible, and maybe the entire global scientific establishment is wrong. Does he think that these various scientists are somehow unaware that Newsweek had an article on global cooling in the 1970s? Or are they aware of the evidence in his book, but are too trapped by their assumptions to be able to incorporate this data rationally? Or does he believe that the whole thing is a con in which thousands of scientists have colluded across decades and continents to fool such gullible naifs as the U.S. Congressional Budget Office, numerous White House science advisors, Margaret Thatcher and so on? Are the Queen of England and the Trilateral Commission in on it too?
But what evidence does Levin present for any of this amazing incompetence or conspiracy beyond that already cited? None. He simply moves on to criticisms of proposed solutions. This is wingnuttery.
There are many reasons to write a book. One view is that a book is just another consumer product, and if people want to buy Jalapeno-and-oyster flavored ice cream, then companies will sell it to them. If the point of Liberty and Tyranny was to sell a lot of copies, it was obviously an excellent book. Further, despite what intellectuals will often claim, most people (including me) don’t really want their assumptions challenged most of the time (e.g., the most intense readers of automobile ads are people who have just bought the advertised car, because they want to validate their already-made decision). I get that people often want comfort food when they read. Fair enough. But if you’re someone who read this book in order to help form an honest opinion about global warming, then you were suckered. Liberty and Tyranny does not present a reasoned overview of the global warming debate; it doesn’t even present a reasoned argument for a specific point of view, other than that of willful ignorance. This section of the book is an almost perfect example of epistemic closure.
Now, obviously Levin was writing about a topic outside his specialty for a general audience, and therefore should be given some leeway. However, as Mr. Manzi details, he appears to be abusing the privilege. An instructive comparison would be Paul Krugman’s recent piece on climate change in the New York Times Magazine, which was similarly written by a non-expert outside his specialty for a popular audience, and also, as it happens, was reviewed unfavorably by Mr. Manzi. While, as Mr. Manzi detailed in a three part series of posts (see Part I, Part II, and Part III here), Krugman gets some things wrong and makes many questionable assertions, it’s clear that Krugman did his homework and at least presented some of the relevant data to his audience.
The point is not that Krugman is right and that Levin is wrong (Manzi and Levin probably agree that Krugman’s approach is wrong-headed); it’s that one took the trouble to make a good faith, if polemical, argument, while the other made a series of sloppy assertions based on conservative boilerplate. There are good reasons to be skeptical about the approach Mr. Krugman and others are advocating: 1) Our modeling capabilities are not advanced enough for confident predictions about when and how much increasing levels of CO2 will impact the climate, 2) Even if they were, there is little reason for confidence that countries like China and India will accept their current standard of living and slow industrialization based on such necessarily tentative estimates; and 3) Climate change is one risk among many that we face; spending vast sums of money on this particular risk (which we may be better able to address later) may leave us ill-equipped to respond to other risks that materialize in the future. None of these arguments are based on a denial of the overwhelming scientific consensus that CO2 does impact the climate (even if we have difficulty quantifying that impact), nor are they based on suspiciously selective arguments from authority. Conservatives who do not want to see Krugman’s approach win the day would do well to follow Mr. Manzi’s example rather than Mr. Levin’s.