Breaking the ‘Hockey Stick’

The Wall Street Journal ran a piece yesterday (on the front page, no less) on the ‘hockey stick’ controversy in climate science :

“From the outset, the [hockey-stick] graph was a target of numerous lobbyists and skeptics. When Mr. McIntyre became interested in it, he quickly teamed up with Ross McKitrick, an economist at Canada’s University of Guelph who’d written a book questioning global warming. (The two met on an Internet chat group for climate skeptics.) In October 2003, Energy & Environment, a British social-science journal known for contrarian views, published an initial critique by the pair. . . . . Dr. Mann and scientists close to him viewed this as a political attack, not science. Dr. Mann offered a strong rebuttal of the Canadians’ 2003 journal article, explaining that it didn’t correctly apply his techniques. In doing so, however, he revealed details of his data and mathematical methods that hadn’t appeared in his original paper. When Messrs. McIntyre and McKitrick pointed this out to Nature, the journal that first published the hockey-stick graph, Dr. Mann and his two co-authors had to publish a partial correction. In it, they acknowledged one wrong date and the use of some tree-ring data that hadn’t been cited in the original paper, and they offered some new details of the statistical methods. The correction, however, stated that “none of these errors affect our previously published results.” Mr. McIntyre thinks there are more errors but says his audit is limited because he still doesn’t know the exact computer code Dr. Mann used to generate the graph. Dr. Mann refuses to release it. “Giving them the algorithm would be giving in to the intimidation tactics that these people are engaged in,” he says.