The famous "Snows of Kilimanjaro" that cap Africa's highest mountain are melting so fast they could be gone within two decades, say experts.

Scientists believe global warming rather than local weather changes is chiefly to blame for the rapid loss of ice from the Tanzanian peak.

A study comparing new measurements with those taken in 2000 show that a layer of Kilimanjaro ice between six and 17 feet thick has vanished since that time.

Not only are the mountain's glaciers retreating at an unprecedented rate, but its remaining ice is thinning.

The researchers predict that if current conditions persist, the mountain could be ice-free as early as 2022.

The "Snows of Kilimanjaro" will then exist only as a memory - and the title of a short story by Ernest Hemingway.

Scientists made their forecast after combining data from aerial photographs and ground measurements of ice thickness.

They found that the total area of Kilimanjaro's ice fields had shrunk by nearly 85% between 1912 and 2007. More than a quarter of the ice present in 2000 was now gone.

The team, led by Professor Lonnie Thompson, from Ohio State University in the US, pointed out that the snows had survived intact for 11,700 years.

Even a 300-year-long drought around 4,200 years ago made little impact on the mountain's ice fields. It was likely the chief cause of the current trend was a fundamental shift in climate, although local changes in cloudiness and snowfall may also be having an effect.