Is methane really worse for the environment than carbon dioxide? - By Brendan I. Koerner - Slate Magazine

Is methane really worse for the environment than carbon dioxide? - By Brendan I. Koerner - Slate Magazine: "Yet methane deserves more attention than it's received so far because, as you note, it's arguably more deleterious to the environment than the widely feared CO2. The Environmental Protection Agency uses a statistic called Global Warming Potential (GWP) to assess the threat posed by various greenhouse gases. GWP measures how much heat one molecule of a gas will trap relative to a molecule of carbon dioxide. Methane has a GWP of 21, which means it's 21 times more effective at preventing infrared radiation from escaping the planet. So, although methane emissions may be relatively piddling, they're definitely a cause for concern. (Their one saving grace is an atmospheric lifetime of just 12 years, versus between 50 and 200 years for carbon dioxide.)"