The first decade of the 21st century is set to be the warmest on record, the head of the World Meteorological Organisation said at UN climate talks Tuesday.
"The decade 2000-2009 is very likely to be the warmest on record, warmer than the 1990s, which were in turn warmer than the 1980s," WMO Secretary-General Michel Jarraud told journalists.
Jarraud also said that the year 2009 would probably rank as the fifth warmest since 1850, the beginning of accurate instrumental climate records.
The December 7-18 climate summit in Copenhagen has brought together 193 countries to hammer out a climate deal to curb global warming and help poor countries cope with its consequences.
"We are in a warming trend, we have no doubt about that, but I would not make predictions for next year," he said when asked whether temperatures would continue to rise in the near term.
Unexpected events such as a major volcano spewing tonnes of heat-filtering debris could lower temperatures, he pointed out.
Climate extremes - including devastating floods, severe droughts, snowstorms, heatwaves and cold snaps - were registered in many parts of the world, the UN weather organ found.
Above-normal temperatures were recorded in all continents except North America, which experiences conditions slightly cooler than the 1961-1990 benchmark average.
Otherwise, there were marked regional variations, the WMO reported.
Extreme warm events were more frequent and intense in the southern part of Australia, southern Asia and South America.
The Arctic sea ice extent during the melt season was the third lowest ever, after the record year of 2007 and the runner-up year 2008.
China will have had the third-warmest year since 1951, and for some regions 2009 was the warmest ever.
The country suffered its worst drought in five decades, with water levels in parts of the Gan and Xiangjiang Rivers the lowest in 50 years.
In India, less-than-average rainfall during the monsoon season caused severe droughts in 40 percent of districts, the WHO reported.
Most of these trends are consistent with long-term forecasts by the UN Intergovernmental Panel on Climate Change (IPCC), which predicts that average global temperatures will rise by up to 6.4 degrees Celsius (11.5 degrees Fahrenheit) unless greenhouse gas emissions are drastically reduced.
The WMO's global temperature analysis is based on three data sets, one of them coming from the Climate Research Unit of University of East Anglia in Britain.
East Anglia's climate science has been the focus of intense scrutiny in recent weeks after email exchanges among its scientists - stolen and posted on the Internet - led to allegations that data was manipulated to exaggerate the threat of global warming.Reuse content