I found an interesting page:
http://cyllene.uwa.edu.au/~dpannell/pd/pd0058.htm
"The Hockey Stick again
I have referred previously to the very public debate about the so-called "hockey stick", a central feature of the most recent report of the Intergovernmental Panel on Climate Change (IPCC) (see PD#6). There have been some interesting developments this year, and a particularly interesting one just recently.
Background: Mann et al. (1998) used a large set of proxy data (mainly measurements of tree ring widths) to estimate temperatures going back centuries. They found that temperatures have been pretty stable since 1400, until they suddenly increased, starting around 1900 (described as the "hockey stick" result). It's a striking result, and the IPCC featured it very prominently in their last set of publications. (Interestingly, Mann himself was lead author of the chapter that featured his result.)
A geologist (McIntyre) and an economist (McKitrick) tried to reproduce the Mann et al. study, and in the process found errors in the basic data, and a major problem with the statistical method. With errors removed, the hockey stick shape is completely lost, and temperatures in the 1900s seem pretty unremarkable. M&M also found that the model has absolutely no statistical power or significance, with an R2 of 0. There are now three refereed publications by M&M describing their work on this, including one in the journal Geophysical Research Letters, where one of Mann's papers was published.
Remarkably, Mann et al. have rejected all criticisms of their work. Worse than that, they have refused to provide the full data set and computer code that they used, so that the results could be reproduced independently. The behaviour of Mann and his team has been rather disturbing given that they are meant to be scientists.
Reading through all the material (and there is a lot of it), it is pretty clear that McIntire and McKitrick have thoroughly won the argument.
Mann's refusal to lie down and concede defeat, even after he has been comprehensively maimed and dismembered, made me think of the wonderful movie, "Monty Python and the Holy Grail". You have probably seen the scene where King Arthur (M&M) has a sword fight with the Black Knight (Mann) (script here). Arthur hacks off one of the Black Knight's arms, then another, then one leg, then the other, but through it all the Black Knight refuses to concede, and keeps haranguing Arthur to continue fighting.
Arthur: What are you going to do? Bleed on me?
Black Knight: I'm invincible!
Arthur: You're a looney!
This is such a wonderful description of the hockey stick "debate". There is Mann, just a head and a bloody torso, madly clinging to the belief that he is still in the fight."