Friday, February 22, 2013

The Hockey Stick Graph at TAL

The Global Warming debate is complicated. One of the major battles is about the hockey stick graph. My understanding is limited, so I have to simplify. This graph shows a long straight line, followed by a quick upturn at the end. The straight part represents the old days, with stable temperatures. The upturn, or the blade of the stick represents the recent increase in temperature. This shape is the essence of global warming. Not just the upturn, but the straightness of the shaft. Because if the shaft is bent, then the upturn loses significance.
Yesterday I attended a lecture in the Third Age Learning series on global warming, by Ross McKitrick. Ross is a global warming denier, who I have blogged about previously. I was expecting a one sided and misleading presentation, but it was far more balanced than I expected. Ross is mentioned in Wikipedia's entry on the hockey stick controversy, as being a critic of it. If I understood Ross correctly, he thinks the normal peer review process is not right for global warming. He believes that an adversarial approach would be better. Now, we appoint a panel of unbiased experts to write the report, then have it reviewed by many other unbiased experts. I assume Ross thinks this can't work because you really can't find unbiased people. So he suggests setting up something like a court of law, two teams arguing opposite sides. I don't know how that would work, but if it did, I think it would be like the Scopes Monkey trial. That trial dealt a real blow to Creationism and religious fundamentalists, but.. here is the problem. Peer reviewed science got the answer right. The Scopes trial got it wrong, it was won by the fundamentalists. But their ridiculous  arguments and tactics were exposed. So for many years after, Creationists were forced to retreat. They have reemerged recently, however.
Although, during the lecture, Ross was much more even handed than I expected, he did present the denier's side of the argument. But I thought it was OK because he did not pretend to be unbiased. Everybody in the audience had gone to several other lectures on global warming. He answered all the questions. He did not engage in any obviously inflammatory and misleading statements.
In the end, I was left puzzling over why he ever signed that ridiculous Evangelical statement on Global Warming. In answer to a question of mine, he claimed to be Anglican, and that church generally supports global warming.
Ross's main contribution to the debate seems to be in successfully questioning the hockey stick shape. Since then other scientists have challenged Ross McKitrick's calculations and methods, but all that is over my head until I go for at least a one year course on the subject. But the Third Age Learning series was a good start.


  1. McKitrick 'believes that an adversarial approach would be better '?

    He's being a bit disingenuous, isn't he? Science is an 'adversarial' process, isn't it? And a process that's served us reasonably well in most areas of research.

    Of course, those in disagreement with the prevailing paradigm often cry foul. Even Einstein refused to believe that, 'God plays dice with the universe.' (But, of course, QM would strongly suggest that He does just that ;-)

    1. He was referring to the method of producing the IPCC reports, where (if I understand corrrectly) there is one chance for a critical view, but the original report writers are given the last say in the final version of the report after they review the dissenting research. So it has an adversarial component, but does not give much of an opening for critics. Of course, I learned about this from Ross McKitrick, so I only heard one side of that story.

    2. OK - thanks for the clarification.

      There are, of course, considerable differences between the (usual peer-reviewed) 'science' on climate change and the IPCC assessment reports.

      The IPCC reports are the output of a committee and, as such, fraught with compromises (not mention subject to political pressures, &c.)

      If anything, the IPCC assessments have been criticized for being far too conservative, especially in terms of their summaries (which likely are all most people, especially politicians, read in any event). Which actually works against McKitrick's contentions.

      ' IPCC higher-ups, fearful of being attacked by climate skeptics, have "bent over backwards" to allow greater input from contrarians.' ...