Kilimanjaro's snow ice cap

One of Mount Kilimanjaro’s most dramatic features is its breathtaking glaciers, which slither across its dormant volcanic plateau and down its crater slope in frigid shades of bluish-green. And one of the saddest claims of some scientists and environmental activists is that those glaciers are disappearing, perhaps before the end of the decade, another victim of rising global temperatures. Athumani Juma doesn’t believe it. A guide who’s been hiking the mountain for the past seven years, he laughed when he was asked about the likelihood that Kilimanjaro’s snowcap would disappear soon. The glaciers, he claimed, no longer are shrinking, but growing. “Before, we were seeing glaciers melting,” he explained during a recent descent from the summit. “But from 2010 to now, we have been seeing new glaciers.” So is one of the most popularly cited examples of the adverse effects of man-made climate change, Kilimanjaro’s great melt, a myth? Yes and no, said Georg Kaser, a professor at Innsbruck University in Austria who’s a leading expert on low-latitude glaciers, including Kilimanjaro’s. The glaciers atop Kilimanjaro’s highest peak, Kibo, are indeed melting, but not because of climate change, he said. They’ve been receding steadily since at least 1880. “According to our understanding, the Kibo glaciers shrink and will disappear not because of changing climate conditions but because of conditions that are unfavorable in principle: It is simply too dry for these glaciers to exist under normal Holocene conditions,” he emailed. The Holocene is how geologists refer to the period from the last Ice Age until now. “The much less clear question is on how the glaciers came to exist, and there are indications that a series of exceptional wet years allowed them to build up during the first half of the 19th century,” Kaser wrote. Kilimanjaro visitors don’t need to worry about the rare tropical glaciers vanishing in the next several years, but the summit will continue to gradually lose more and more of its icy grandeur. Projections suggest that the glaciers will disappear by 2046, give or take 10 or 20 years, Kaser said. That’s because the atmosphere around Kilimanjaro doesn’t contain enough water to sustain large ice bodies, according to Kaser’s research. Climate change might have affected the precipitation patterns in the region, but local temperatures don’t appear to be a driving factor in the glacier retreat. A separate study published in the journal Global and Planetary Change in November 2010 suggested that deforestation in Kilimanjaro’s lower rain forests could be accelerating the glaciers’ retreat because it leads to drier air around the mountain’s peak. What about Juma’s claim that Kilimanjaro’s glaciers have swelled instead of shrunk the past few years? Tanzania National Parks said it couldn’t help clarify that; the park service doesn’t monitor glacier movements on the mountain. According to Kaser, there’s no evidence to support Juma’s observation. Such a reversal would require an increase in precipitation over the past two to three years, which didn’t occur, he said.