Saturday, May 05, 2007

The decay of the hockey stick: who did it

Hans von Storch, a former chief of the German Donald Duck Society, is a pleasant person to communicate with and he has done important things in the climate science. But his and Eduardo Zorita's text in
is simply a misleading presentation of the history of science. They explain that the methodology behind the hockey stick graph by Mann, Bradley, and Hughes - MBH98 and MBH99 - has been shown to be flawed - something that everyone except for Alexander Ač, Whole Life Times, and Michael Mann now knows to be the case.
AA and MM have different reasons, however. AA believes it because he is a naive Czechoslovak countryside green idealist. MM and Whole Life Times believe it because of a clash of interests.
They describe some details of the history - including the report of the National Academy of Sciences - but don't mention Ross McKitrick and Steve McIntyre (M&M) or the Wegman report that confirmed the work of M&M.

The picture above is wrong.

What used to be the main evidence of an exceptional character of the 20th century climate and consequently the strongest evidence for man-made global warming (especially in the third IPCC report in 2001) has been transformed into a bombshell, a climate scandal of the decade and a climatological counterpart of cold fusion based on flawed statistics. Nevertheless, Michael Mann - the supreme cold fusion guy - still has the stomach to spread his confusion and propaganda at a bizarre ideological blog called "RealClimate.ORG."

I happened to follow the fate of this particular paper and papers that were trying to reproduce it and validate it at least since 2004 which is why I know that M&M were by far the most important technical critics of the hockey stick papers. They studied the methodology in detail and localized its main problems in Energy & Environment 2003. Building on their detailed and constantly increasing understanding of the subject, especially in Steve's case ;-), they wrote an even more clear paper refuting the hockey stick graph in Geophysical Research Letters 2005 when they finally showed that the hockey stick shape is put into the algorithm itself.

Meanwhile, von Storch et al. did something that is more comprehensible for most of us - they have simply demonstrated in Science 2004 that the method of Mann et al. has underestimated the natural variability of the temperature in the past by a factor of 2-5. Well, if you remove 80% of natural variability, it becomes somewhat easier to argue that variability is due to humans.

Other critics including von Storch may be viewed as people who followed M&M and who have used their advantage of being "mainstream scientists" to get more credit with less original effort. There exists clear evidence that both von Storch and Zorita have endorsed the important work by M&M a few years ago.

I join Steve McIntyre, William Connolley, and others who urge Dr. von Storch and Dr. Zorita to give M&M the credit they undoubtedly deserve.

Some additional frequently visited climate articles on The Reference Frame


  1. When you have narrowed down the universe we live in from 10^500 possibilities to one, we'll talk.

  2. Dear khurram,

    the number of minima of the effective potential is determined by the laws of physics, not by the desire of imbeciles and crackpots - so if you're not satisfied with the right answer whatever it is, please move to a different multiverse.