Tuesday, June 19, 2007

My stupidity on display

In yesterday's post I wrote

Gore made the claim [that retreating snows on Mt. Kilimanjaro were attributable to global warming] based upon the research of Lonnie Thompson, a geologist who attributed the melting snows of Kilimanjaro to global warming, using the inductive reasoning that the snows on Kilimanjaro were part of the global retreat of glaciers due to increased global temperatures.
While inductive reasoning certainly played a part in Dr. Thompson's work, it is a gross mischaracterization on my part to imply that was the only reason he suggested that snow retreat was due to warming. As Andrew Revkin explained back in March 2004

Dr. Lonnie G. Thompson, the Ohio State University glaciologist whose work first focused attention on Kilimanjaro's fading ice, said he saw ample evidence that melting was eating away at what remained.

His specialty is extracting cylinders of layered, ancient ice from tropical glaciers, and when his team drilled into one of the mountain's ice fields in 2000, water flooded out of the hole. In the resulting cores, shallow layers contained elongated bubbles -- strong evidence of melting and refreezing -- while deeper layers had none.

More jarring was the violent collapse of a 10-story-tall clifflike face of one of Kilimanjaro's ice fields in January 2003, witnessed and photographed by trekkers. The collapse sent a huge cascade of ice and water gushing across the flanks of the ancient crater.

''This all suggests that what we are seeing at least in the last 20 years or so is different,'' Dr. Thompson said. He believes the mountain may be close to a threshold at which melting will become the dominant force eroding the ice. ''The balance of evidence says something bigger is going on in the system,'' he said.
But the criticism that Gore, at the least, should have included a qualification about the uncertainty of how much warming was responsible for the amount of decline on the mountain remains, as Revkin also pointed out that

Most experts in the Kilimanjaro debate accept three things: for more than a century, its ice has been in a retreat that is almost assuredly unstoppable and was not caused by humans; so far, there is scant data on conditions there; and the main scientific question now is how, and how much, climate shifts driven by heat-trapping emissions are accelerating that trend.
That information should have been included in Gore's slideshow presentation, and without such qualification the images of Kilimanjaro should have not been included in the presentation, and should be removed from future versions, especially given the paper just published with further challenges the view that warming is playing a role in the retreating ice trend.

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