COMPUTER models used by climatologists till date have come under a cloud.

American researchers Peter Pilewski of National Aeronautical Space Agency's Ames Research Centre and Francisco Valero of the Scripps Institute of Oceanography indicate that clouds can absorb much more energy - up to 30 per cent of the incoming sunlight - than previously thought. (New Scientist, Vol 145, No 1970). Since even a small discrepancy in these matters could cause major shifts in atmospheric circulation in the tropics, the older models will have to go.