Intense precipitation expected worldwide

Scientists at the National Center for Atmospheric Research in Boulder, Colo., say global warming will produce more intense precipitation around the world.

NCAR researchers say the greatest increases in precipitation will occur in the tropics, with heavier rain or snow also falling in northwestern and northeastern North America, northern Europe, northern Asia, the eastern coast of Asia, southwestern Australia, and parts of south-central South America during the 21st century.

"The models show most areas around the world will experience more intense precipitation for a given storm during this century," says lead author Gerald Meehl.

The scientists say global warming from greenhouse gases produces warmer sea surfaces, boosting evaporation, while warmer air holds more moisture. As that soggy air moves from the oceans to the land, it dumps extra rain per storm.

In the Mediterranean and the U.S. Southwest, although intensity increases, average precipitation decreases. The authors attribute the decrease to longer periods of dry days between wet ones. The heavier rain and snow will most likely fall in late autumn, winter and early spring, while warmer months may still bring a greater risk of drought.

The findings appeared recently in Geophysical Research Letters.

Copyright 2005 by United Press International