Tarpaulin can save Kilimanjaro ice cap
Dec 01, 2003
The celebrated ice cap on Africa’s loftiest peak could vanish within 20 years, taking with it a unique scientific resource
The celebrated ice cap on Africa’s loftiest peak could vanish within 20 years, taking with it a unique scientific resource.
Now a Zimbabwean scientist believes that the ice can be saved, by covering it with a giant tarpaulin.
Tanzania’s ice-crowned Mount Kilimanjaro is not only a top tourist attraction and a national symbol. Its frozen cap, gradually deposited over millennia, also records the history of East Africa’s climate.
“If it goes, we’ll lose some really precious information about the climate of the recent past,†says climatologist and Zimbabwe native, Euan Nisbet of Royal Holloway University of London.
An expedition to Kilimanjaro in 2000 found just 2.2 square kilometres of ice on the summit 80% less than covered it in 1912. The peak will be bare rock by 2020 if the ice continues to disappear at this rate, says expedition leader Lonnie Thompson, a geologist at Ohio State University in Columbus.
Thompson’s team collected ice cores that preserve an archive of African climate over the past 11,700 years, the only record of its kind.
Although its tempting to blame the ice loss on global warming, researchers think that deforestation of the mountain’s foothills is the more likely culprit. Without the forests’ humidity, previously moisture-laden winds blew dry. No longer replenished with water, the ice is evaporating in the strong equatorial sunshine.
Reforestation is the best long-term solution, but trees will not grow fast enough to save the ice, argues Nisbet. A temporary band-aid is needed. “The most obvious and simple solution would be to hang a white drape over it to reflect sunlight and reduce wind,†he says.
A white, synthetic drape hung over the 30-metre cliff-like edges of the ice sheet, where most of the evaporation is occurring, might just do the trick, Nisbet says. But other scientists are sceptical. “This is probably not something that would buy us much time,†says Thompson.
“My feeling is that the glaciers will be lost no matter what we do. Nature is a huge force and it’s very hard to stop once it’s in motion.â€
“It’s feasible that we could bring about the glacier’s demise even more quickly,†warns climatologist Doug Hardy of the University of Massachusetts Amherst.
Although the tarpaulin would reflect most of sun’s energy away from the ice, warmth would penetrate it and be trapped inside.
The cover could then act as a blanket, speeding up the melting. With an estimated 50-100 tonnes of tarpaulin needed to cover the ice’s edges, not to mention the effort required to place it on the mountain, the resources might be better spent on collecting more ice cores, Hardy says.
But there is more at stake for impoverished Tanzania and Africa than just a record of climate, says Nisbet. “The ice of Kilimanjaro is an icon for all of Africa,†he says. “Tanzania has tried very hard to protect its natural assets, and it deserves a bit of help if something can be done.â€
Nature
Now a Zimbabwean scientist believes that the ice can be saved, by covering it with a giant tarpaulin.
Tanzania’s ice-crowned Mount Kilimanjaro is not only a top tourist attraction and a national symbol. Its frozen cap, gradually deposited over millennia, also records the history of East Africa’s climate.
“If it goes, we’ll lose some really precious information about the climate of the recent past,†says climatologist and Zimbabwe native, Euan Nisbet of Royal Holloway University of London.
An expedition to Kilimanjaro in 2000 found just 2.2 square kilometres of ice on the summit 80% less than covered it in 1912. The peak will be bare rock by 2020 if the ice continues to disappear at this rate, says expedition leader Lonnie Thompson, a geologist at Ohio State University in Columbus.
Thompson’s team collected ice cores that preserve an archive of African climate over the past 11,700 years, the only record of its kind.
Although its tempting to blame the ice loss on global warming, researchers think that deforestation of the mountain’s foothills is the more likely culprit. Without the forests’ humidity, previously moisture-laden winds blew dry. No longer replenished with water, the ice is evaporating in the strong equatorial sunshine.
Reforestation is the best long-term solution, but trees will not grow fast enough to save the ice, argues Nisbet. A temporary band-aid is needed. “The most obvious and simple solution would be to hang a white drape over it to reflect sunlight and reduce wind,†he says.
A white, synthetic drape hung over the 30-metre cliff-like edges of the ice sheet, where most of the evaporation is occurring, might just do the trick, Nisbet says. But other scientists are sceptical. “This is probably not something that would buy us much time,†says Thompson.
“My feeling is that the glaciers will be lost no matter what we do. Nature is a huge force and it’s very hard to stop once it’s in motion.â€
“It’s feasible that we could bring about the glacier’s demise even more quickly,†warns climatologist Doug Hardy of the University of Massachusetts Amherst.
Although the tarpaulin would reflect most of sun’s energy away from the ice, warmth would penetrate it and be trapped inside.
The cover could then act as a blanket, speeding up the melting. With an estimated 50-100 tonnes of tarpaulin needed to cover the ice’s edges, not to mention the effort required to place it on the mountain, the resources might be better spent on collecting more ice cores, Hardy says.
But there is more at stake for impoverished Tanzania and Africa than just a record of climate, says Nisbet. “The ice of Kilimanjaro is an icon for all of Africa,†he says. “Tanzania has tried very hard to protect its natural assets, and it deserves a bit of help if something can be done.â€
Nature