Photograph by David Pluth, NGS
Published November 2, 2009
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Ernest Hemingway must be reaching for a bottle of grappa in his grave. The snows of Kilimanjaro—inspirations for a Hemingway story of the same name—could be gone by 2022, a new study confirms.
The ice atop Kilimanjaro "continues to diminish right on schedule for disappearing, unfortunately, in the next couple of decades," said glaciologist Lonnie Thompson at Ohio State University in Columbus.
For decades scientists have documented the disappearing glaciers on Kilimanjaro, whose peak is Africa's highest point.
Whether Kilimanjaro's ice loss is due to global warming or more local factors, though, has been a point of debate. Some studies have suggested the ice loss is due primarily to what some see as local factors: less snowfall and more sublimation—a process that turns ice directly into water vapor at below freezing temperatures.
The new study appears to strengthen the argument that global warming is to blame—and that, in addition to sublimating the ice atop Africa's tallest mountain, rising global temperatures are also melting the ice.
"What we are seeing on Kilimanjaro is global climate change," Thompson said.
(Another view: "Kilimanjaro's Glaciers May Last Longer Than Predicted" .)
Kilimanjaro's Disappearing Ice "Part of Climate Change"
According to Thompson, the drier and less cloudy conditions leading to sublimation on Tanzania's Kilimanjaro are part of a suite of changes driven by global warming.
"You change the temperature profile of this planet, you are going to change precipitation and cloudiness and humidity and temperature," he said. "Those are all part of climate change.
"And so to say that that Kilimanjaro is not responding to global climate change is untrue."
Kilimanjaro's Thinning Ice Is Deceptive
Thompson and his colleagues have studied Kilimanjaro's dwindling ice for several decades.
The mountain, they say, has lost 85 percent of its glacial ice since 1912. What's more, 26 percent of the ice that remained in 2000 was gone by 2007, the last time Kilimanjaro's ice was precisely mapped.
Related Video: Introduction to Kilimanjaro
In addition, ice core data from one of the glaciers shows signs that the surface has melted and refrozen, contributing to the thinning of the glaciers.
The levels of ice surrounding a stake embedded in the bedrock below a glacier in the center of Kilimanjaro's mountaintop crater, for example, indicates that 50 percent of the glacier's thickness has been lost since 2000.
That particular glacier is thinning at rate of 17 feet (5.2 meters) a year and could be gone by 2018, Thompson noted.
(Also see: climbing guide to Kilimanjaro.)
Kilimanjaro Glaciers "Decapitated"
Before-and-after shots show the snowy cap atop Kilimanjaro growing smaller and smaller over the years.
But "when you do a visual like with an aerial photograph, you don't really see [Kilimanjaro's glaciers] thinning. And one year in the future there will be a glacier there—but it will be very thin—and the following year it will be gone."
As much ice is now being lost through thinning as from retreat at the margins, Thompson said.
"These glaciers are being decapitated from the surface down."
Findings published today by the journal Proceedings of the National Academy of Sciences.
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