The Coal Companies Try to Silence Michael Mann

Since I was just complaining about attempts by climate alarmists to stifle scientific opposition to their findings, it only seems fair that I report on an attempt by coal companies to intimidate Penn State into canceling a speech by climate scientist Michael Mann. Kevin Drum:

We've documented the long-term effort to malign Pennsylvania State University climate scientist Michael Mann here rather extensively. Now a coal-backed group is running a smear campaign targeting an upcoming speaking event Mann is holding on campus.

The Common Sense Movement and the Secure Energy for America Political Action Committee (CSM/SEAPAC) have started a petition asking Penn State to cancel Mann's Feb. 9 speech. In the petition, they rehash "Climategate" and accuse him of "allegedly manipulating scientific data to align with his extreme political views on global warming." The group offers a template letter for people to send to "daily newspapers near you" attacking Penn State for hosting a speech by "someone of such questionable ethics."

In two major papers in 1998 and 1999, Mann and colleagues presented evidence for the so-called "hockey stick" model of climate change. Their model, presented in the graph above, asserts that the 20th-century increase in global temperature is a dramatic departure from the fluctuations of the previous thousand years. This model has been hotly debated ever since -- wikipedia has a whole entry on the hockey stick controversy, to which I refer the curious for more detail -- and Mann has been accused of "manipulating" his data. Which, of course, he has, since the raw data on global temperature has to be approached using mathematical models and can't be understood at all without "manipulation." Whether Mann's model is the right one is a hard question, but there is nothing unscientific about his approach and it is just wrong to accuse him and his colleagues of "questionable ethics." They have made their data and their assumptions public, and anybody can check them. Plenty of people have, and some of them have disputed Mann et al.'s statistical methods. But this is scientific debate at a very high level, and I have trouble following the mathematical arguments about these models. It is not "fraud," as Mann's Republican critics like to claim, but a scientific dispute. At the moment the consensus seems to be with Mann, that the late 1990s were the warmest period in a thousand years. On the other hand, though, the world does not seem to have gotten much warmer in the decade since.

Mann has engaged in political action, based on his fears about the future of the climate, but that, it seems to me, is his right. He has also criticized some uses of his own data by environmentalists, including the printing of the hockey stick graph without error bars in a 2001 report from the U.S. National Commission on Climate Change. Penn State has every right to invite him to speak, and the coal companies are being deeply sleazy in trying to stop him.