GENEVA?Greenhouse gas concentrations reached record levels in 2009, the UN's weather agency said Wednesday, warning that global warming could set off even greater methane emissions from the Arctic.
"Greenhouse gas concentrations have reached record levels despite the economic slowdown. They would have been even higher without the international action taken to reduce them," said Michel Jarraud, secretary general of the World Meteorological Organization.
"In addition, potential methane release from northern permafrost, and wetlands, under future climate change is of great concern and is becoming a focus of intensive research and observations," he added.
Carbon dioxide concentrations reached 386.8 parts per million in 2009, up 38 percent from pre-industrial times.
Methane, the second most important greenhouse gas after carbon dioxide, meanwhile reached 1,803 parts per billion, up 158 percent from pre-industrial times.
According to the WMO, following a period of stabilization between 1999 and 2006, atmospheric methane began to increase again from 2007 to 2009.
"There are two possible reasons for that ? in 2007, there was a warmer Arctic which produced a lot of extra emissions, plus in 2007 and 2008, there was an increase in precipitations in the tropicals," said Oksana Tarasova, a WMO scientist.
"We don't know the proportions which work more. It's difficult to distinguish between these two particular sources," she said, adding that it was unclear if the trend would continue in 2011.
For Len Barrie, who is co-director at WMO's research department, changes are needed urgently in order to reverse the situation.
"If we continue business as usual, we will not achieve the level of atmospheric concentration that would allow a two degree Celsius target," he told AFP, referring to a bid to limit global warming to two degrees Celsius (3.6 Fahrenheit) above pre-industrial temperatures.
He added that to start decreasing the levels of greenhouse gases, it was necessary to "stop totally the emissions."
This means that the usage of fossil energy should be halted, he said.
Representatives from 194 countries meet in the Mexican resort city of Cancun from November 29 to December 10 for a new bid to strike a deal to curb greenhouse gases.