Tuesday Meteorological Organization said in Copenhagen, the past decade has been the warmest since records began 160 years ago.The year 2009 ranks in the top ten warmest year.
"Despite 1998 being the warmest individual year, the last 10 years have clearly been the warmest period in the 160-year record of global surface temperature maintained jointly by the Met Office Hadley Centre and the Climatic Research Unit at the University of East Anglia," the statement from the U.K.'s national weather service said.
Figures show a steady rise in temperatures over the past four decades, with 2009 listed as likely to be the fifth warmest year since 1850. The U.K. data are derived from a rolling average of 10 years in the 2000 to 2009 period.
"In the last decade we have seen that the temperatures haven't gone up very much, but they are clearly a lot warmer then they were in the previous decade," said Doctor Vicky Pope, the head of climate change advice at the Met office, Xinhuanet reports.
The Met Office says the new figures prove global warming is a continuing issue, and blames the increase on greenhouse gas emissions.
Directgov quoted Vicky Pope as saying, "The climate is changing, and man's activities are leading that change, and that's causing this rise in temperature. We see differences in the rate of rise for different decades, but overall the average temperatures are rising for those decades."
The figures suggest this year will become the fifth warmest year since records began in 1850.
And data from the UN's weather experts, the World Meteorological Organisation, shows that for large parts of southern Asia and central Africa, 2009 will have been the warmest year on record , Directgov reports .
"This is an indication that the world has not been cooling since 1998," said Dr Vicky Pope of the Met Office's Hadley Centre for Climate Prediction and Research, referring to claims by climate change sceptics that since 1998, the hottest year of all, the trend has changed from warming to cooling.
"We are in a warming trend, we have no doubt about that," said Michel Jarraud, secretary general of the Geneva-based WMO. Both organisations also revealed that, although the final data is not yet in, 2009 is likely to turn out to be the fifth warmest individual year since records began, up from the comparatively cooler 2008 - which, influenced by the La Ni ña cold-water weather phenomenon in the Pacific, was 11th in the record.
The La Niña has now been replaced by its opposite, an El Niño, where a periodic warming of the waters of the eastern tropical Pacific off the coast of South America affects temperatures and weather patterns across the world. The current El Niño is partly responsible for the warmer 2009, and some meteorological scientists are already canvassing the possibility that it may make 2010 a new record-breaker.
Although 2009 is likely to be fifth, the WMO announced yesterday that in some regions of the world it had been much hotter.
"In large parts of southern Asia and of central Africa, it is likely to be the warmest ever on record," said Mr Jarraud, Independent reports.