the area hit by severe drought worldwide has increased from nearly 12 per cent in the 1970s to 30 per cent in the early 2000s, according to scientists at the National Center for Atmospheric Research (ncar), Colorado, usa . Almost half of that change is due to global warming rather than decrease in rainfall or snowfall, they warn.

"As surface air temperatures increase over land, water holding capacity of the air increases and thus its demand of moisture. This has been a primary cause for the widespread drying during the last two-three decades,' the team led by Aiguo Dai said in a paper that appeared in the December 2004 issue of Journal of Hydrometeorology (Vol 5, No 6) .

The team found in the last 30 years widespread drying occurred mainly over much of Europe, Asia, western and southern Africa, eastern Australia and Canada. A large jump in areas categorised as very dry occurred in the early 1980s due to an El Ni