US experts see more global warming
2013-01-16 09:40
Washington - Global temperatures were above average for the 36th straight year in 2012 and the planet is likely to chalk up more record warm highs over the coming decade, US scientists said on Tuesday.
The year 2012 marked the ninth or 10th warmest on record, depending on the measurement. Space agency Nasa put the average temperature at 14.6°C, 0.6°C higher than in the 20th century.
Data released last week found that the continental US experienced its warmest year on record in 2012. However, several regions including parts of Alaska, western Canada, central Asia and the Antarctic were cooler.
James Hansen, director of Nasa's Goddard Institute for Space Studies, said it was likely that an upcoming year would break the record high global temperature set in 2010.
"What we find is that the ocean is getting warmer - that shows that the planet is out of balance, there is more energy coming in than going out," Hansen told reporters on a conference call.
"Therefore we can predict with confidence that the next decade is going to be warmer than the last one," he said.
Sceptics
Most mainstream scientists believe that global temperatures and extreme weather events are rising due to industrial emissions of carbon and other greenhouse gases, which trap heat inside the atmosphere.
The average global temperature has risen by 0.8°C since 1880 when records were first kept, according to Nasa.
The planet has been warmer than the 20th century average every year since 1976 and only one year in the last century - 1998 - was warmer than 2012.
Climate sceptics have used comparisons from 1998 to argue that global warming has stopped.
Hansen said that 1998 was not representative as it featured a powerful El Niño, the phenomenon of a warm Pacific Ocean current, and that temperatures have kept rising when factoring in the El Niño and opposite La Niña effects.
"The most recent decade is clearly much warmer than that decade," he said.
Hansen said that scientists also needed to study whether a rise in the use of industrial aerosols in China and other developing countries has tempered warming. Aerosols, despite causing other harm, have a cooling effect.
Nasa said the global temperature in 2012 was the ninth warmest since the start of records. The National Oceanic and Atmospheric Administration, which calculates its findings differently, put 2012 as the 10th warmest.
World leaders in slow-moving UN-led negotiations have pledged to contain warming to no more than 2°C above pre-industrial levels, although experts believe current efforts are insufficient to meet the goal.
The draft of the Third National Climate Assessment, a scientific study to US policymakers, said on Friday that temperatures could rise between 2.8°C and 5.6°C after 2050 if little action is taken.
A World Bank report warned in November that global warming was on course to devastate coastal communities and food production, setting back development for millions of the world's poor.
