The winter just ending in the Northern Hemisphere is the warmest ever recorded, according to the US National Oceanic and Atmospheric Administration (NOAA).
The three-month December-February period - winter in the North, summer in the South, saw the combined global temperature of both the oceans and the land strike an average that was 0.72 degrees Celsius higher than the 20th Century mean, NOAA data shows.
Jay Lawrimore of NOAA National Climatic Data Center said a combination of long-term global warming and a cyclical El Nino even in the Pacific Ocean appeared to be the main factors.
The average land temperature globally was the warmest on record while the average ocean temperature equalled the highest recorded for the northern winter period of 1997-98.
That year was the third warmest northern winter period on record, the second warmest occurring in 2003-04.
NOAA data is used by the Intergovernmental Panel on Climate Change (IPCC) in its landmark assessment reports.
Reuters 19/3/07
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