The 11,000-year-old snow cap of Mount Kilimanjaro, famed in literature and beloved by tourists, will be gone in two decades, according to re-searchers who say the ice fields on Africa's highest mountain have shrunk by 80% in the past century.

Research shows the oldest ice layers on the famed mountain were deposited during an extremely wet period starting about 11,700 years ago.

But, a temperature rise in recent years is eroding the 45-metre-high blocks of ice that gave Kilimanjaro its distinctive white cap.

"The ice will be gone by about 2020," said Thompson, the first author of a study appearing today in the journal Science.