A new report published today in the Proceedings of the National Academy of Science notes that the ice cap atop Mount Kilimanjaro in Tanzania continues to recede. The authors of the report, however, do not state a consensus of opinion on the reason for the continued melting.

The scientists compared aerial photographs of the mountain taken over time to obtain horizontal measurements of the retreating ice. To obtain changes in depth measurements, the scientists used instruments installed on Kilimanjaro in 2000.

The New York Times reports that the lead author, Lonnie Thompson, a glaciologist at Ohio State University, concluded that the recent melting is “unique” . . . because it contained “elongated bubbles - signs that melting and refreezing had occurred in recent years.” According to Thompson, who analyzed deep ice cylinders, this type of surface melting has not occurred in over 11,700.

The report authors do discuss and reference the work of Georg Kaser, a glaciologist at the the Institute for Geography of the University of Innsbruck in Austria, who believes that the recent melting is caused by a decline of humidity and moisture. According to Kaser’s research, there has been a marked reduction in precipitation and cloud cover in East Africa during the 20th C. that has led to an increase in solar radiation and a decrease in snow.

While the study authors do not dismiss Kaser’s conclusions, neither do they embrace them. They also, however, do not state outright that man-made global warming is too blame. The authors state their conclusion as follows:

“The climatological conditions currently driving the loss of Kilimanjaro’s ice fields are clearly unique within an 11,700-year perspective. These observations suggest that warmer near-surface conditions observed in the region, coupled with observed vertical amplification of temperature in lower latitudes (23-25), are playing an important role. Regardless of the contributions of various drivers, the ice fields atop Kilimanjaro will not endure if current conditions are sustained and adaptive actions to minimize the potential impacts should be developed quickly.” (emphasis added)

So the authors appear to clearly believe that “adaptive actions” can be taken to “minimize” the melting. It’s interesting that they, however, refer to “various drivers” causing the melting and shy away from calling it man-made global warming.

Further reading: http://www.pnas.org/content/early/2009/10/30/0906029106.full.pdf+html
http://www.americanscientist.org/issues/feature/the-shrinking-glaciers-of-kilimanjaro-can-global-warming-be-blamed/

Photo: Mount Kilimanjaro http://www.flickr.com/photos/piccadillywilson/71905107/

Copyright 2009 - K.J.Collins