Proc. Natl Acad. Sci. USA doi: 10.1073/pnas.0906029106 (2009).

Credit: Lonnie Thompson Research Team, Ohio State University

Mount Kilimanjaro, known for its snowy cap, could be ice-free within several decades if climate change continues unabated. This stark warning comes from a new study, which shows that ice cover atop the African mountain has declined by 26 per cent since 2000.

Glaciologist Lonnie Thompson, of the Byrd Polar Research Center at Ohio State University in Columbus, and colleagues used a combination of aerial photographs and ground-based observations to study changes in ice cover on Kilimanjaro from 2000 to 2007. Their observations confirmed that, across the mountain, ice fields are shrinking in size and thinning rapidly. Analysis of an ice core from Kilimanjaro's northern ice field revealed clear evidence of surface melting in the upper 650 millimetres, a pattern not seen elsewhere in the 49-metre core. This suggests that loss of ice on the mountain is more severe now than at any time in the past 11,700 years.

The actual causes of glacier loss in the region are still under investigation. But the authors say that several lines of evidence suggest local climatological changes are insufficient to account for the observed losses. Furthermore, they note that the situation is not unique, with ice fields worldwide shrinking.