Melting mountains a water 'time bomb'

Glaciers and mountain snow are melting earlier in the year than usual, meaning the water has already gone when millions of people need it during the summer when rainfall is lower, scientists warned on Monday.

"This is just a time bomb," said hydrologist Carmen de Jong at a meeting of geoscientists in Vienna.

Those areas most at risk from a lack of water for drinking and agriculture include parts of the Middle East, southern Africa, the United States, South America and the Mediterranean.