Here’s the end of the piece:
Michael Mann’s reaction has so far been dismissive. He attacked the M&M paper as a “political stunt,” seemingly before reading it. His retort was transmitted through the website of a sympathetic freelance journalist, and has muddied the debate considerably.
Mann claims that M&M used the wrong data set, and that they only used 112 proxies when 159 were needed. But M&M point out on their web site that Mann’s original research paper contained only 112 proxies, and that these were the proxies Mann instructed his associate to provide to them.
Mann also asserts that many other paleoclimatologists have been able to replicate his results closely. But this response does not address the question whether those experts uncovered the same errors in the data that M&M, coming to the issue fresh, were able to find.
The whole affair bears strong resemblance to the recent Bellesiles controversy. Emory University historian Michael Bellesiles won a Bancroft Prize for his argument that gun ownership in early America was not widespread. It took an amateur historian, Clayton Cramer, to point out that this claim could not be substantiated on the basis of actual gun-ownership records. Eventually, an Emory University investigation strongly criticized Bellesiles, and the Bancroft Prize was withdrawn.
So far, it looks like the errors in Mann’s data set were accidental. Yet it will be interesting to see how far the proponents of strong action on climate change go to defend the data without addressing the fundamental question: Are the numbers as proposed by M&M right? If they are, then the climate debate will need to change.