Originally Posted April 19, 2008:
In fact, even though Taylor cherry picks the sentences he feels suit his argument best, if you go and read the entire article you will find that the two scientists in question do not claim, as Mr. Taylor does, that global warming has nothing to do with the ice loss on Kilimanjaro. Rather, they have this to say:
Year-to-year variability and longer-term trends in the seasonal distribution of moisture are influenced by the surface temperatures of the tropical oceans, which, in turn, are influenced by global climate. On many tropical glaciers, both the direct impact of global warming and the indirect one—changes in atmospheric moisture concentration—are responsible for the observed mass losses. The mere fact that ice is disappearing sheds no light on which mechanism is responsible.
The fact that the loss of ice on Mount Kilimanjaro cannot be used as proof of global warming does not mean that the Earth is not warming. There is ample and conclusive evidence that Earth's average temperature has increased in the past 100 years, and the decline of mid- and high-latitude glaciers is a major piece of evidence. But the special conditions on Kilimanjaro make it unlike the higher-latitude mountains, whose glaciers are shrinking because of rising atmospheric temperatures. Mass- and energy-balance considerations and the shapes of features all point in the same direction, suggesting an insignificant role for atmospheric temperature in the fluctuations of Kilimanjaro's ice.
It is possible, though, that there is an indirect connection between the accumulation of greenhouse gases and Kilimanjaro's disappearing ice: There is strong evidence of an association over the past 200 years or so between Indian Ocean surface temperatures and the atmospheric circulation and precipitation patterns that either feed or starve the ice on Kilimanjaro. These patterns have been starving the ice since the late 19th century—or perhaps it would be more accurate to say simply reversing the binge of ice growth in the third quarter of the 19th century. Any contribution of rising greenhouse gases to this circulation pattern necessarily emerged only in the last few decades; hence it is responsible for at most a fraction of the recent decline in ice and a much smaller fraction of the total decline.