The ice that was present in 1912 gradually decreased by 85% by 2000, and by 2007 another 26% of the amount in 2000. This was the first time that the volume of the ice in Kilimanjaro was measured. The tests were conducted by Lonnie Thompson, a professor at Ohio State University. Professor Thompson said that the scientists have also detected elongated bubbles in the surface of the ice field, which occur when the ice melts and refreezes. There is no evidence this melting and refreezing has occurred at any other period going back 11,700 years.
"The fact that so many glaciers throughout the tropics and subtropics are showing similar responses suggests an underlying common cause," Thompson said.
Change in cloudiness and weather could have also been factors in the retreat of the ice, especially in recent decades, scientists said. These findings were first published in the journal proceedings of United States National Academy of Sciences (NAS) on November 3, 2009.