Catastrophic storms like Hurricanes Katrina and Stan took weather extremes to new levels in 2005, with flooding and heatwaves touching almost every continent.
GENEVA Catastrophic storms like Hurricanes Katrina and Stan took weather extremes to new levels in 2005, with flooding and heatwaves touching almost every continent, the United Nations weather body WMO said on Thursday.
But in an annual review, WMO Secretary-General Michel Jarraud said that while high temperatures and heavy rains could probably be linked to global warming, this phenomenon could not yet be firmly blamed for the summer's Caribbean hurricanes.
"This year is currently the second warmest on record, and could end up being the warmest once all the figures are in," Jarraud told a news conference. "It has certainly been exceptional in the intensity of its storms."
A long-time weather scientist who has headed the Geneva-based World Meteorological Organisation for the past two years, he said extreme heat -- often bringing severe drought -- had spread across all continents but Europe.
Europe itself -- mainly in its eastern and south-eastern regions -- had suffered both torrential rains and flooding, which also affected Bangladesh, China, New Zealand and Guyana in South America, among other areas.
And the tropical systems that swept around the Caribbean and the Gulf of Mexico trailing destruction and human tragedy were -- taken together -- the worst ever, with 26 named storms easily breaking the previous record of 21 in 1933.
Of these, 14 became hurricanes -- two more than the previous record in 1969 -- and seven were classified as "major hurricanes", including Katrina which devastated New Orleans and other U.S. Gulf cities in August and killed some 1,300 people.
MOST INTENSE HURRICANE
Hurricane Wilma, which tore around coastlines in Central America in October, was the most intense ever recorded in the region, Jarraud said.
Earlier that month, Hurricane Stan had swept across Guatemala and El Salvador, laying waste to many poor communities, destroying coffee and other crops and killing more than 1,000 in mudslides and floods.
Jarraud said it was not yet possible to assert that global warming was responsible for generating the hurricanes.
"The honest answer is: we don't know if it is," he said. "A lot of research is being done, and the IPCC (the U.N.'s advisory Intergovernmental Panel on Climate Change) will be issuing a new report in 2007, and that could shed more light on the question."
However, the WMO chief said, global warming was clearly tied to the increasing incidence of heat waves, and the spread of deserts in areas short of rain. "We can be much more confident about saying that," he declared.
Jarraud said Arctic sea-ice was melting -- another phenomenon linked to global warming -- more than ever before, and that the average cover in the key month of September was down 20 percent on the average for 1979-2004.
Overall, the average temperature at the earth's surface so far for 2005 had been 0.48 degrees centigrade (0.86 degrees Fahrenheit) higher than the comparable average for 1961-90 of 14 degrees centigrade, used as a reference period, the WMO said.
The hottest year since governments began sharing data was 1998, when the average surface temperature was 0.54 degrees centigrade above the reference period average.