The UN's World Meteorological Organisation (WMO) has confirmed 2010 was the warmest year on record, verifying a "significant" long-term trend of global warming.

The trend also helped to melt Arctic sea ice cover to a record low for December last month, the WMO said in a statement.

Last year "ranked as the warmest year on record, together with 2005 and 1998," the WMO added, confirming preliminary findings released at the global climate conference early December that were based on a 10-month period.

"The 2010 data confirm the Earth's significant long-term warming trend," WMO secretary-general Michel Jarraud said.

"The 10 warmest years on record have all occurred since 1998."

In 2010, the global average temperature was 0.53 degrees Celsius, above the 1961 to 1990 mean that is used as a yardstick for climate measurements, according to the WMO.

That exceeded 2005 levels by 0.01 C and was 0.02 C above the 1998 mark, but within a margin of error that made the difference between the three years statistically insignificant, according to the WMO.

"Arctic sea-ice cover in December 2010 was the lowest on record" for the month, the WMO said.

Sea ice around the northern polar region shrank to an average monthly extent of 12 million square kilometres, 1.35 million square kilometres below the 1979 to 2000 December average, according to the UN weather agency.

Over past decade, global temperatures have been the highest-ever recorded for a 10-year period since the beginning of instrument-based climate records.

Last month, even before the year was over, Mr Jarraud confirmed that 2001 to 2010 set a new record as the warmest decade ever.

The WMO says that the temperature observations on their own do not pin the cause on man-made greenhouse gases, although it believes this is confirmed separately by other research into carbon emissions in the atmosphere.

- AFP