Volume 10, Number 36: 5 September 2007
In a fascinating article published in the July-August issue of American Scientist, Mote and Kaser (2007) present an illuminating review of the comprehensive field work that has been conducted over the past twenty years on tropical glaciers in general - and those of Mount Kilimanjaro in particular - in which one of them (Kaser) was intimately involved, writing within the context of current concerns over possible CO2-induced global warming and the connection that a number of high-level climate alarmists (Al Gore, John McCain and Hillary Clinton come to mind) have attempted to make between this conjectured phenomenon and the disappearing ice fields of what they call the "shining mountain."
The two researchers begin by stating "there is scant evidence ... of a direct connection between current global climate trends and the shrinking of the ice cap atop Kilimanjaro in tropical East Africa, despite its new role as a climate-change poster child," particularly as portrayed in the film An Inconvenient Truth. In fact, they say that "warming fails spectacularly [our italics] to explain the behavior of the glaciers and plateau ice on Africa's Kilimanjaro massif .. and to a lesser extent other tropical glaciers."
So what has actually been observed atop Kilimanjaro over the years? .. and what has caused the shrinking of its fabled ice cap?
Observations suggest that between 1880 and 2003, there was a shrinkage of almost 90% in the ice-covered area of Kilimanjaro; but Mote and Kaser note that "much of that decline [66%] had already taken place by 1953." This "pacing of change," in their words, "is at odds with the pace of temperature changes globally." In fact, at the closest point of reanalysis temperature data availability in the vicinity of Kilimanjaro's peak, they say "there seems to be no trend since the late 1950s." Consequently, and based on a long list of other observations, the two researchers ascribe the long-term wasting away of ice on Kilimanjaro "to a combination of factors other than warming air - chiefly a drying of the surrounding air that reduced accumulation and increased ablation."
Another interesting conclusion of Mote and Kaser is that "the historical records available suggest that the large ice cap described by Victorian-era explorers was more likely the product of an unusually wet period than of cooler global temperatures," which leads them to the most mind-bending conclusion of all.
"Imagine," they say, "a scenario in which the atmosphere around Kilimanjaro were to warm occasionally above 0 degrees," so that "sensible and infrared heating of the ice surface would gradually erode the sharp corners of the ice cap [and] gentler slopes would quickly develop." If precipitation increased simultaneously, as is typically predicted by most climate models, they say that "snow could accumulate on the slopes and permit the ice cap to grow," which scenario leads them to the ultimate conclusion that, "ironically, substantial global warming accompanied by an increase in precipitation might be one way to save Kilimanjaro's ice." Alternatively, or concurrently, they suggest that "substantially increased snowfall, like the 2006-07 snows, could blanket the dark ash surface so thickly that the snow would not sublimate entirely before the next wet season," and that "once initiated, such a change could [also] allow the ice sheet to grow."
Clearly, the misguided scientific, political and theatrical rushes to judgment that have elevated Kilimanjaro's predicted demise by CO2-induced global warming to iconic status should give everyone pause to more carefully evaluate the evidence, or lack thereof, for many similar doom-and-gloom claims related to the ongoing rise in the air's CO2 content, which are likewise paraded as truth, but that could well be 180 degrees out of phase with reality.
Sherwood, Keith and Craig Idso
Reference
Mote, P.W. and Kaser, G. 2007. The shrinking glaciers of Kilimanjaro: Can global warming be blamed? American Scientist 95: 318-325.