Methane levels in the atmosphere are increasing again after 9 years of no increase. Decreasing agricultural methane releases over the last decade have resulted in flat methane concentrations in the atmosphere. But it is suspected that increasing industrialization in Asia and recent melting of permafrost releasing frozen methane has caused these emissions to begin rising again.
Methane is 23 times more powerful of a greenhouse gas than carbon dioxide. But there is good news: Methane only last about dozen years in our atmosphere, then it breaks down in to carbon dioxide.
http://www.noaanews.noahttp://www.noaanews.noaa.gov/stories2008/20080423_methane.htmla.gov/stories2008/20080423_methane.html