Geoscience Reference
In-Depth Information
reliance on peer-review” in our field. This claim, of course, goes against every principle of scientific
practice; peer review is a key ingredient in the self-correcting processes of science. Perhaps this
dismissal of the importance of peer review was, at least in part, an attempt to innoculate the Wegman
Report against the criticism that, unlike the NAS report, it was not peer reviewed in any formal sense.
The Heat Is On
One week after the release of the Wegman Report, on July 19, as temperatures soared near or above
the century mark over much of the country—including Washington, D.C.—during what would later
come to be known as the 2006 North American heat wave, Barton called a hearing of the
subcommittee on Oversight and Investigations. Entitled “Questions Surrounding the 'Hockey Stick'
Temperature Studies: Implications for Climate Change Assessments,” the hearing was set up for a day
the committee had already learned I would be unavailable.
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I did my best, nonetheless, to follow the
developments from afar.
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Wegman and McIntyre were witnesses, along with a number of climate scientists. I had
recommended the committee invite paleoclimatologist Tom Crowley in my absence. His climate
modeling experiments had not only reproduced the hockey stick pattern, but had also attributed the
anomalous recent warmth to human causes. Other scientists who testified at the hearing were the NAS
committee chair Gerry North, NOAA scientist Tom Karl, and Hans Von Storch.
With assistance from Wegman and McIntyre, Barton used the hearing to advance one very
specific, trivially true, but in reality totally inconsequential claim: that centering conventions of
principal component analysis can influence the character of the first principal component obtained in
a PCA of a dataset.
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On that narrow point, North, as well as everyone else involved in this debate
(including us!) were in agreement. Wegman and McIntyre were conspicuously silent, however, on the
only issue that actually mattered: whether these conventions had any material impact on the result of
the MBH analysis, correctly performed. Even if one accepted Wegman and McIntyre's claims, would
it make a difference? North and the NAS had already provided a definitive answered to that question:
No. But Barton—a firm subscriber to the “up is down, black is white” alternative reality of climate
change denial—was intent on finding some credible witness who might be willing to argue otherwise.
Perhaps Barton was hoping that he had found such an individual in Hans Von Storch. After all,
Barton had specifically cited Von Storch's criticism of the hockey stick in his original, July 2005
letter. Von Storch, as it turns out, was the one witness who spoke clearly and unambiguously to this
point at the hearing: Asked about the effect of PCA centering conventions on the MBH98/MBH99
reconstruction, Von Storch replied “the effect is very minor … it really doesn't matter here.”
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The
impact of a respected climate scientist viewed by some as a critic of our work dismissing with such
dispatch the essence of the Barton, Wegman, and McIntyre criticisms was profound.
What about Wegman's other chief claim; that that my collaboration with a wide group of other
researchers—forty-three coauthors in total—somehow compromised the underlying validity of our
work? North dismissed the notion out of hand, explaining that my broad collaborations were
something he would “probably look very favorably on if I were considering him for tenure.” North
used the example of physicists responsible for the great discoveries of the early twentieth century—
Einstein, Bohr, and Heisenberg—to underscore the absurdity of Wegman's “social network analysis,”
