Kilimanjaro's Famous Icy Peaks Are Thawing Fast

(USATODAY) -- Climate change could cause the legendary snow and ice atop Mount Kilimanjaro to disappear within the next 25 years, scientists report today in the journal Proceedings of the National Academy of Sciences.

For the first time in almost 12,000 years, based on ice-core analysis, Africa's highest peak probably will be ice-free as early as 2022 or as late as 2033, says glaciologist Lonnie Thompson of Ohio State University, who led the study.

"Of the ice cover present in 1912," Thompson and his colleagues write in the paper, "85% has disappeared and 26% of that present in 2000 is now gone."

The research backs up what Thompson's team first reported in an earlier study. "In that 2002 report, we showed what we expected would happen," he said in a phone interview. "This paper showed that by 2007, the loss of ice is right on track."

For the new study, he says, his team examined the volume of ice loss, not just surface coverage. They found that the ice not only is shrinking in size but also is thinning rapidly. "Nearly equivalent ice volumes are now being lost to thinning and lateral shrinking," the authors write in the study.

The researchers combined measurements of ice area from aerial photographs and ground measurements of changes in ice thickness to determine how fast the ice is disappearing.

Similar analyses of other tropical glaciers in South America, Asia and Oceania have revealed similar loss of glacial ice, Thompson says.

The study findings also make clear that although rising temperatures play a part in the glaciers' retreat, drier and less cloudy conditions than in the past - partly the result of human-caused climate change - also are contributing to "sublimation" and melting of the glaciers atop the mountain. Sublimation is the evaporation of ice directly into the atmosphere.

"This is a very thorough documentation of the changes in the Kilimanjaro glaciers," says Kevin Trenberth, head of the climate analysis section at the National Center for Atmospheric Research in Boulder, Colo., who was not part of the study. Trenberth says he has no doubt "that the glaciers are retreating and have continued to retreat since their last study."

The "snows of Kilimanjaro" were made famous in the Ernest Hemingway short story of that name in 1938, in which the main character notices "as wide as all the world, great, high and unbelievably white in the sun, was the square top of Kilimanjaro."