The snow-capped peak of Tanzania’s Mt. Kilimanjaro is one of the most famous vistas on the African continent. Soon, though, you might not be able to see it in person: The mountain’s 11,000-year-old snow cap shrank by 80 percent in the past century and could be gone within two decades if temperature trends continue, according to a report published today in the journal Science. The disappearance of the ice cap is bad news for water supplies in mountain villages and for the tourism industry in Tanzania, where Kilimanjaro brings in more foreign currency than any other single source. As for the cause of the change, Douglas Hardy, at the University of Massachusetts at Amherst, said, “Evidence is mounting that human influences on climate are causing glaciers to retreat.” But, he cautioned, “Kilimanjaro’s glaciers have little in common with mid-latitude Alpine glaciers and we must accept that simple explanations are not always possible.”