Sunday, January 25, 2009

Denialist Machine At Work

A short excerpt from Christopher Booker's Telegraph article on an important new paper re the the warming of Antarctica gives us a glimpse as to how such research gets treated by the Denialist movement:

One of the first to express astonishment was Dr Kenneth Trenberth, a senior scientist with the UN's Intergovernmental Panel on Climate Change (IPCC) and a convinced believer in global warming, who wryly observed 'it is hard to make data where none exists'. A disbelieving Ross Hayes, an atmospheric scientist who has often visited the Antarctic for Nasa, sent Professor Steig a caustic email ending: 'with statistics you can make numbers go to any conclusion you want. It saddens me to see members of the scientific community do this for media coverage.

1) Inflate the credentials of skeptics. Mr. Hayes appears to have visited the area exactly twice, within the past five years, though when he writes

...In the late 1980s helicopters were used to take our personnel to Williams Field from McMurdo Station due to the annual receding of the Ross Ice Shelf... suggests a knowledge of the place extending back decades.

Furthermore, his brief email contains at least one demonstrably false claim:

One climate note to pass along is December 2006 was the coldest December ever for McMurdo Station.

Not so.

2) Inflate the differences among real scientists. While generally characterizing the new paper as "good work", what I think Kenneth Trenberth is objecting too is (from "Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year"):

...we use statistical climate-field-reconstruction techniques to obtain a 50-year-long, spatially complete estimate of monthly Antarctic temperature anomalies. In essence, we use the spatial covariance structure of the surface temperature field to guide interpolation of the sparse but reliable 50-year-long records of 2-m temperature from occupied weather stations. Although it has been suggested that such interpolation is unreliable owing to the distances involved1, large spatial scales are not inherently problematic if there is high spatial coherence, as is the case in continental Antarctica4.

Trenberth is one of those leery of this kind of statistical interpolation. The paper's authors think it works under the circumstances. A real, scientific exchange will perhaps ensue, and Booker will undoubtedly ignore it.

(Note: Trenberth expresses other objections, and the paper's authors answer as best they may, here.)


meddy said...

Outline of paper & discussion here --
State of Antarctica: red or blue?

Some less derisory press treatments --
Study Finds New Evidence of Warming in Antarctica By KENNETH CHANG
Scientists solve enigma of Antarctic 'cooling' Damian Carrington

Paul S said...

"A real, scientific exchange will perhaps ensue . . ."

One can always hope but it's doubtful when one of the authors, Michael Mann, appears to view the study less as scientific endeavour and more as a hammer to pummel anyone who does not immediately agree with his findings.

Dr. Trenberth's comment, he of the IPCC, remains the most astute:

". . . it is hard to make data where none exists."

I am sure he also will be promptly labelled a denier soon by various warmers.