How does an economist become interested in climate change? Our interests intersect in at least three areas. Economists devise methods to minimize the cost to the economy of environmental protection and cleanup. Economics and climatology have similar methodological problems. Few questions we investigate can be answered through controlled experimentation. Both disciplines establish control through complex mathematical models verified with equally complex statistical testing. If lack of controlled experimentation were not enough, we generally have bad data. Finally, all scientists have an interest in the integrity of science, and I fear that science may take a hit from politicized and bad science.[1]
Before I proceed, I do not claim to know a great deal about climate science. The scientists involved were important contributors in their fields and on the IPCC, but how important I don't know. Some of the involved scientists managed important databases, but I do not know the percentage of the scientific literature that made use of it.
In class, I place a great deal of emphasis on the scientific process. The purpose of scientific training is to help practitioners think clearly and free of biases which tie conclusions to prior beliefs, eliminating the need to conduct research. The scientists involved in this scientific scandal violated the process at almost every step. An early step of scientific enquiry involves a search of the relevant literature, which they appeared to do, and incorporation of that literature into the formulation of models, and possibly into hypotheses, steps they did not take. They were aware of criticism of their own work and ignored it, and worse, they attempted to keep opposing opinions from seeing the peer-reviewed light of day.
Another important part of the scientific process involves testing hypotheses, and again, it appears these scientists behaved badly. At the least, they manipulated data used to produce graphs explaining their findings to the general public. They withheld data and statistical techniques that they used from scientists that were skeptical of their work. While this is a very human thing to do, it is not the scientific thing to do. The released data also suggests that one of the four great databases showing long-term temperature change was not as sound as the Climate Research Unit at UEA claimed. Lower quality data lowers the strength of conclusions.
The peer review process is, or at least should be, the gold standard of scientific research. It is supposed to be anonymous, meaning that the scientists who wrote the paper do not know those who review it, and those who review it do not know the authors. Reputation should not influence the scientific judgement of what is published. The released e-mails clearly demonstrate efforts to control scientific discourse without regard to merit.[2]
[1] Daniel Botkin, one of the first ecologists to explore the impact of global warming, expressed similar concerns in a EconTalk podcast, "Botkin on Nature, the Environment and Global Warming," November 26, 2007). Botkin demonstrates wonderful scientific restraint in not exceeding the bounds of his expertise.
[2] Megan McArdle suggests that I might have an idealized view of the scientific process. She is probably correct. She writes ("ClimateGate," The Atlantic: Asymmetrical Information, November 24, 2009).
A few of you have asked what I think about ClimateGate. Mostly I concur with Tyler Cowen and Robin Hanson: I have so far seen no evidence of the kind of grand conspiracy that some critics have charged. Rather, to my mind this is about how real science (unfortunately) does sometimes get done.
Scientists are human beings. They react to pressure to "clean up" their graphs and data for publication, and they gang up on other people who they dislike. Sometimes they're right--there's a "conspiracy" to keep people who believe in N-rays from publishing in physics journals, but that's a good thing. But sometimes they're wrong, and a powerful figure or group of people can block progress in science.
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