US scientists have said that 2014 was the hottest year on record, marking the third time in a decade that a new record has been set.

With the exception of 1998, the 10 warmest years on record have now occurred since the year 2000, analysis of surface temperature measurements show.

Both the National Oceanic and Atmospheric Administration (NOAA) and NASA reported on Friday that 2014 was the hottest year in 135 years of record-keeping.

Earlier, the Japanese weather agency and an independent group out of University of California Berkeley also measured 2014 as the hottest on record.

NOAA said 2014 averaged 14.6C, 1.24 degrees above its 20th-century average. It had previously reported that Earth set yearly heat records in 2010 and 2005.

NASA, which calculates temperatures slightly differently, put 2014's average temperature at 14.7C, which is 1.22 degrees above their average, which they calculate for 1951-1980.

Global warming

"While the ranking of individual years can be affected by chaotic weather patterns, the long-term trends are attributable to drivers of climate change that right now are dominated by human emissions of greenhouse gases," Gavin Schmidt, director of NASA's Goddard Institute of Space Studies in New York, said in a statement.

Rutgers University's Jennifer Francis and other climate scientists also said the results show that global warming continues unabated.

"The globe is warmer now than it has been in the last 100 years and more likely in at least 5,000 years," she said.

"Any wisps of doubt that human activities are at fault are now gone with the wind."

Source: Agencies