The Melting of Mountain

Scientists agree that global warming will cause glacial melt, and that glacial melt will contribute to sea-level rise. Nonetheless, there remain numerous disagreements about the exact process and extent of glacial melting and its relation to global warming. As just one example, the most famous melting ice in the world may be the glacier atop Mount Kilimanjaro in Tanzania. The icecap on Mount Kilimanjaro has declined visibly over the last hundred years, and this phenomenon is often blamed on global warming. For example, Lonnie Thompson, an Ohio State University researcher of ancient climates, has linked the Kilimanjaro melt to global warming. Thompson said that Kilimanjaro had lost 25 percent of its ice between 2000 and 2006. In speaking about a number of glaciers, including Kilimanjaro, he said that

"they're not just retreating, they're accelerating [their retreat]____

And it raises the question of whether this might be a fingerprint of [human-caused global] warming."8 Further research as of 2009 led Thompson to link the melting ice even more clearly to global warming, and to predict that the glaciers atop Kilimanjaro could disappear entirely by 2034.9

Together, the Antarctic and Greenland ice sheets contain enough water to raise the level of the ocean by more than 223feet (68m).

Other researchers disagree that the melt of Kilimanjaro is caused by global warming, however. For example, researchers Philip Mote of the University of Washington and Georg Kaser of the University of Innsbruck argue that Kilimanjaro's glacial melt was well under way in the first half of the 1900s, before global warming would have been an important factor. Instead,

Mote and Kaser blame other factors, such as a decline in regional snowfall. Mote noted in 2007 that there were many other glaciers about which there was "absolutely no question that they are declining in response to the warming atmosphere." The glacier on Kilimanjaro simply happened not to be among them.10

It is important to note that mountain glacial melt can have a number of important effects beyond raising sea levels. The melting of the glacier on Kilimanjaro, caused by global warming or not, may damage the mountain's attractiveness as a tourist destination, with dramatic economic consequences for Tanzania. More broadly, the melting of mountain glaciers can result in the creation of huge lakes and dangerous floods. Flooding in Yosem-ite National Park in 1997 and 2005, and a devastating flood in Bhutan in 1994 were all linked to glacial melting. Henry Diaz of the U.S. Office of Oceanic and Atmospheric Research warned that with global warming "These kinds of things are likely to occur more frequently in the future."11

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