Kilimanjaro and Global Warming

I’m surprised it took as long as a day for denialists like Patrick Michaels to gloat over the finding that the loss of the ice caps on Kilimanjaro – an example used by Al Gore in An Inconvenient Truth – has turned out to be from causes other than global warming (a more in depth paper).

But one thing they usually won’t mention when they quote these articles – how Kilimanjaro was the exception that proved the rule.

In an article in the July-August edition of American Scientist, Mote and Kaser also cited decreased snowfall in the area as a driver of melt because bright, white snow reflects sunlight back into the atmosphere; if there’s not new snow, sunlight gets absorbed and melts the ice.

The scientists say that other declining glaciers, like the South Cascade Glacier in Washington, would be a better poster child for the plight of glaciers in a warming world, which are indeed diminishing overall as a result of climate change. It’s just that Kilimanjaro is one exception to the trend. Government photographs taken from 1928 to 2000 have shown that the South Cascade Glacier lost half its mass in that time.

“There are dozens, if not hundreds, of photos of mid-latitude glaciers you could show where there is absolutely no question that they are declining in response to the warming atmosphere,” Mote said.

Why am I not surprised that they never seem to mention this part of the article. Hmmm. Anyway, the best overview of the problem I think comes from Geek Counterpoint:

Kilimanjaro has pretty much been used as a “poster child” for global warming by Al Gore & co. Meanwhile, climate change “skeptics” have used the data for Kilimanjaro’s natural thawing as supposed “proof” that climate change isn’t behind any glacier’s retreat. Essentially, both camps have fallen victim to their own versions of confirmation bias (you see what you expect / want to see…).