Wednesday, October 27, 2004

Another Blow to Chicken-Little Science

I wrote recently about a report by Richard Muller that took a chunk out of the hockey-stick theory of global warming:
This [hockey-stick] plot purports to show that we are now experiencing the warmest climate in a millennium, and that the earth, after remaining cool for centuries during the medieval era, suddenly began to heat up about 100 years ago -- just at the time that the burning of coal and oil led to an increase in atmospheric levels of carbon dioxide....

Canadian scientists Stephen McIntyre and Ross McKitrick have uncovered a fundamental mathematical flaw in the computer program that was used to produce the hockey stick....

This improper normalization procedure [used in the computer program] tends to emphasize any data that do have the hockey stick shape, and to suppress all data that do not....
Muller was, in the end, rather restrained in his criticism of the authors of the hockey-stick theory, namely, University of Massachusetts geoscientist Michael Mann and colleagues. Not so restrained is a research paper published recently in the journal Science by Professor Hans von Storch and colleagues at the Institute of Coastal Research at Geesthacht, Germany. Scientists Willie Soon and David R. Legates, writing at Tech Central Station, report:
In short, the new paper...confirms what several other climate researchers have long stipulated. The hockey stick curve -- which is a mathematical construct, as opposed to actual temperature information recorded at individual locations -- is problematic because it yields air temperature changes on timescales of a few decades to a century that are simply too muted to fit the phenomena of the Medieval Warm Period (ca. 800-1300) and Little Ice Age (ca. 1300-1900), which are well recorded in historical documents and recognized in indirect climate data from growths of tree-rings and corals or isotopic content in ice cores and stalagmites collected around the world.

This is traditional science, with results from one group tested by others. What makes this case important, though, was explained by Von Storch in Der Spiegel:
"The Mann graph [i.e., the hockey stick of IPCC TAR] indicates that it was never warmer during the last ten thousand years than it is today. ... In recent years it [the hockey stick] has been elevated to the status of truth by the UN appointed science body, the Intergovernmental Panel on Climate Change (IPCC). This handicapped all that research which strives to make a realistic distinction between human influences and climate and natural variability."
According to Soon and Legates, Von Storch calls the hockey stick "junk" or "rubbish."