LONDON/OSLO Last year was the world's second warmest behind 1998 in a temperature record dating back to 1850, adding to evidence of a long-term trend of climate change, data from British institutes showed on Wednesday.
Phil Jones, director of research at Britain's Climatic Research Unit (CRU), told Reuters world surface temperatures in 2010 were about 0.5 degrees Celsius (0.9 Fahrenheit) above the average for 1961-1990.
His unit, compiling data with the Met Office Hadley Center, is one of three main groups worldwide tracking global warming. Last week the other two, based in the United States, said 2010 was tied for the hottest on record.
Jones said the data showed that all but one year in the past decade were among the 10 hottest on record, underlining a warming trend linked to human emissions of greenhouse gases.
"All the years from 2001 to 2010, except 2008, were in the top ten," he said. The U.N.'s World Meteorological Organization compiles a ranking from all three sources.
The fight against global warming suffered a setback in the wake of the financial crisis, slowing funding for renewable energy projects and knocking momentum from efforts to agree a climate deal to succeed the Kyoto Protocol in 2013.
The new data appeared to bolster evidence for man-made climate change, after leaked e-mails, including from the CRU, showed climate scientists in 2009 sniping at skeptics. Errors made by a U.N. climate panel also exaggerated the pace of melt of glaciers in the Himalayas.
Last year was 0.498 degrees Celsius (0.9 Fahrenheit) above the 1961-1990 average, the CRU and Hadley data showed, compared with 1998's 0.517 degree. The nearest year below 2010 was 2005, at 0.474 degree warmer than the long-term average.
Droughts in Russia, China and Argentina, which stoked record food prices, coupled with floods last year in Pakistan and China have underlined the threat from extreme weather.
Some parts of Europe, Russia and the United States suffered a cold 2010, against the global trend.
Last month, a U.N. meeting in Cancun, Mexico, agreed to raise climate aid for poor countries, but failed to convince analysts that the world could agree a binding deal on emissions after the present round of the Kyoto Protocol ends in 2012.
Governments agreed in Cancun to limit average global warming to less than 2 degrees Celsius above pre-industrial levels, but national emissions pledges so far are too weak to meet that target. Temperatures have already risen about 0.8 degrees C.
Energy security fears may more successfully drive investment in low-carbon alternatives to fossil fuels, but environmental investors say evidence of climate change helps.
The 10 warmest years have been since 1998, when temperatures were boosted by a strong El Nino weather event, a natural shift which brings warm waters to the surface of the Pacific Ocean every few years.
The U.S. National Climatic Data Center at the National Oceanic and Atmospheric Administration and NASA's Goddard Institute for Space Studies (GISS) said last week that 2010 was tied for the hottest year with 2005.
The U.S. and British groups use similar observations but in slightly different ways. For example, GISS takes greater account of Arctic weather stations, where warming has been fastest.
All the warmest years are separated by only a few fractions of a degree.
(Reporting by Gerard Wynn in London and Alister Doyle in Oslo, Editing by Janet Lawrence)