Drought Flood*

Posted 4/8/2003 12:41 PM Updated 4/8/2003 12:41 PM

2002's warmth could deepen climate-change concerns

By Dan Vergano, USA TODAY

NICE, France — Last year rang in as the second-warmest on record, weather experts reported Monday, making 2002 the continuation of a trend of warmer years.

The "State of the Climate" report also described 2002 as a year that marked the worst flooding in Europe in 100 years and a record drought for parts of North America. In fact, scientists found that 2002 drought patterns in the southwestern USA match Dust Bowl records from the 1930s.

A contributing factor to the drought was a warm winter that delivered less snow to mountains, which act as a frozen reservoir until the spring melt.

The report, presented at a joint assembly of European and U.S. geophysicists here, comes amid increasing concern about climate change forced by emissions of "greenhouse" gases such as carbon dioxide. Increased warming in much of the Northern Hemisphere over the past five years has led many atmospheric scientists to conclude that man-made climate change is taking place.

One feared side effect of the phenomenon is more extreme weather — floods, hurricanes, storms and other events — so climate experts observe each year's weather with great interest. Every year has its own moments of extreme weather, says climatologist Anne Waple of the National Climatic Data Center in Asheville, N.C., "but, by and large, 2002 saw a lot more warm records."

Only 1998 stands as a warmer year since weather records have been kept, Waple says. On average, 2002's temperatures worldwide were about 1 degree Fahrenheit above normal.

The annual climate report, compiled by 26 scientists from eight countries, noted other unusual weather patterns. Snowfall was extreme in the Northern Hemisphere, creating a near-record low snowfall in February and the second-largest snow cover ever in October. Snowfall was heaviest in Russia and eastern Canada, as well as in the Himalayas.

Europe's floods, which caused about $9 billion in damage in Germany alone, sprang from a rainy storm system that stalled over the continent for days.

Hurricane and tropical storm activity was very low overall, but September saw more tropical storms than any one month on record.

Because of a waning El Niño, the disruption in the ocean-atmosphere system that was the culprit behind much of the extreme weather, any wet weather effects seen in North America are unlikely to continue. "It may even transition to 'La Niña,' certainly for the USA not a good situation," Waple adds; that weather pattern could worsen drought in southwestern states.

The drought in places such as Australia was exacerbated because it hit agricultural areas hard, says climate expert Graham Farquhar of the Australian National University. His research, also presented Monday, suggests climate change may heighten both drought and flooding by affecting in unexpected ways how water moves through the environment.

For example, more carbon dioxide causes plants to consume less water, in turn sending less of it into the atmosphere. And higher temperatures may cause more evaporation from lakes and oceans, but that may cause more rain over humid areas. Thus, water-rich regions may get more flooding and water-poor ones may see more drought.

Polar ice, a bellwether for climate scientists, receded in the Arctic Ocean. Unusually warm weather in Russia added to stormy seas and seems to have driven the decrease, Waple says. Antarctic sea ice decreased, also part of a trend.

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