Glaciers high in the Himalayas are dwindling faster than anyone thought, putting nearly a billion people living in South Asia in peril of losing their water supply.

Throughout India, China, and Nepal, some 15,000 glaciers speckle the Tibetan Plateau. There, perched in thin, frigid air up to 7200 metres above sea level, the ice might seem secluded from the effects of global warming.

But just the opposite is proving true, according to new research published in the journal Geophysical Research Letters.

Professor Lonnie Thompson of Ohio State University and a team of researchers travelled to central Himalayas in 2006 to study the Naimona'nyi glacier, expecting to find some melting.

Mountain glaciers have been receding all over the world since the 1990s and there was no reason this one, which provides water to the mighty, Indus, and Brahmaputra Rivers, should be any different.

But when the team analysed samples of glacier, what they found stunned them.