More on the infamous "hockey stick"

In a comment here, Ilya Maclean wrote:

...McIntyre and McKitrick criticisms have little relevance with respect to the final shape of the Hockey stick graph...

That's simply not true.

A piece by Michael Crichton is here.

Now the question is, is this twentieth-century temperature rise extraordinary? For that we must turn to the second graph by Michael Mann, which is known as the “hockey stick.”

This graph shows the results of a study of 112 so-called proxy studies: tree rings, isotopes in ice, and other markers of relative temperature. Obviously there were no thermometers back in the year 1000, so proxies are needed to get some idea of past warmth. Mann’s findings were a centerpiece of the last UN study, and they were the basis for the claim that the twentieth century showed the steepest temperature rise of the last thousand years. That was said in 2001. No one would say it now. Mann’s work has come under attack from several laboratories around the world. Two Canadian investigators, McKitrick and McIntyre, re-did the study using Mann’s data and methods, and found dozens of errors, including two data series with exactly the same data for a number of years. Not surprisingly, when they corrected all the errors, they came up with sharply differing results.

But still this increase is steep and unusual, isn’t it? Well, no, because actually you can’t trust it. It turns out that Mann and his associates used a non-standard formula to analyze his data, and this particular formula will turn anything into a hockey stick---including trendless data generated by computer.

Physicist Richard Muller called this result “a shocker…” and he is right. Hans von Storch calls Mann’s study “rubbish.” Both men are staunch advocates of global warming. But Mann’s mistakes are considerable. But he will get tenure soon anyway.

The "hockey stick" debate in this hysteria shares some similarities with the Luneau video debate in the Ivory-bill hysteria. Make no mistake--when you side with Michael Mann (one of the founders of realclimate) on the hockey stick, it's like siding with Lammertink/Fitzpatrick/Pulliam on the Luneau video. Once you learn more about the hockey stick and figure out that it's been shattered, it's like joining the Sibley/Bevier/etc side on the Luneau video debate.