Kilimanjaro's Ice Fields Are Melting Away

By Maria Godoy

WASHINGTON, DC, October 17, 2002 (ENS) - Once described by author Ernest Hemingway to be "as wide as all the world," the ice fields atop Mount Kilimanjaro have now retreated to their lowest surface extent in the past 12,000 years and could vanish within the next two decades, new research suggests.

The findings, based on the first ever climate history of Africa using ice core analysis, are all the more troubling, scientists say, because these glaciers provide one of the few archives of historical climate change in the tropics, where long ice core records are rare.

The snowcaps on the icy peak of Kilimanjaro are shrinking. (Photo by Rick Thomson, courtesy Thomson Safaris)

Now new findings published today in the journal "Science" indicate the glaciers are melting at a rate of about one-half meter (1.6 feet) per year, supporting previous predictions that, if current climate conditions continue, the ice caps will vanish by 2020.

"We found that the summit in the ice fields has lowered by at least 17 meters since 1962," said Lonnie Thompson, professor of geological studies at Ohio State University and lead author of the "Science" study.

The margin of Kilimanjaro's northern ice field, Thompson said, has retreated more than two meters (6.6 feet) in the last two years.

"That's more than two meters' worth of ice lost from a wall 50 meters high ­ that's an enormous amount of ice," said Thompson, who heads a National Science Foundation funded research team that has been tracking the glacial retreat since 2000.

Professor Lonnie Thompson. (Photo courtesy Ice Core Paleoclimatology Group, Ohio State University)

The ice cores indicated that around 9,500 years ago, Lake Chad, now Africa's fourth largest body of water, spanned an area greater than the Caspian Sea. Evidence also surfaced of a cold spell on the continent that lasted from about 1270 AD to 1850 AD.

Core composition also suggested that at least three prolonged periods of drought have hit Africa over the past 12 millennia. The last of these massive droughts occurred 4,000 years ago and lasted for three centuries, threatening the rule of the Pharaohs and transforming the Sahara Desert into the barren region it is today, Thompson said.

During that last drought, the ice fields of Kilimanjaro covered less surface than they do today ­ an area now estimated at about 2.6 square kilometers (one square mile), said Douglas Hardy, a geoscientist with the University of Massachusetts at Amherst and coauthor of the "Science" report.

Ice cores, like this one from the Dasuopu Glacier in the Himalayas, provide an invaluable history of climate changes. (Photo by Lonnie Thompson)

"In 20 years, we may reach a point where for the first time in 12,000 years there may not be any ice on the mountain," Hardy said. "It's a time of incredible change for these glaciers."

Hardy said this rate of change is consistent with global warming trends seen on other glaciers around the world. But he worries that Kilimanjaro has become an inappropriate poster child for the greenhouse gas effect.

Hardy cautions that the available evidence from satellites, aerial maps and temperature readings is too thin to link global warming conclusively to Kilimanjaro's melting glaciers. Other factors, such as atmospheric humidity and changes in precipitation, might also be at play.

Professor Douglas Hardy. (Photo courtesy University of Massachusetts at Amherst)

Thompson agreed, but stressed that Kilimanjaro's vanishing ice fields should be viewed as part of a larger trend of global climate change currently underway that "should be taken very seriously."