Friday, February 18, 2005

NHL on strike, so here's your hockey stick

Environmentalists refer to the holy graph which demonstrates temperature change over time as the hockey stick because of its' profile. However, there is a small problem.

But that will mean far-reaching industrial changes. Mr. McIntyre's complaint is that supporters of Kyoto pushed for it by wielding a graph, the hockey stick, whose validity they'd never fully scrutinized. "Give me a break -- we are making billion-dollar decisions," he says, noting that businesses, by contrast, must carefully audit their financial statements and projections.

The problem, says Mr. McIntyre, is that Dr. Mann's mathematical technique in drawing the graph is prone to generating hockey-stick shapes even when applied to random data. Therefore, he argues, it proves nothing. Statistician Francis Zwiers of Environment Canada, a government agency, says he now agrees that Dr. Mann's statistical method "preferentially produces hockey sticks when there are none in the data."

Mainstream scientists have also been scrutinizing the hockey stick. One, Hans von Storch of Germany's GKSS center, has presented theoretical findings arguing that Dr. Mann's technique could sharply underestimate past temperature swings. Indeed, new research from Stockholm University on historical temperatures suggests past fluctuations were nearly twice as great as the hockey stick shows. That could mean the 20th-century jump isn't quite so anomalous.
One of (computer scientist and writer, Jerry)Pournelle's Laws states "You can prove anything if you can make up your data." I will now add another Pournelle's Law: "You can prove anything if you can keep your algorithms secret."
thanks to
John Ray.

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