CATCHING UP TO AMERICA:

Methane's Impacts On Climate Change May Be Twice Previous Estimates (SPX, Jul 19, 2005)

According to new calculations, the impacts of methane on climate warming may be double the standard amount attributed to the gas. The new interpretations reveal methane emissions may account for a third of the climate warming from well-mixed greenhouse gases between the 1750s and today. [...]

Controlling methane could reap a big bang for the buck. Another bonus of this perspective is that in order to manage greenhouse gases, policy decisions must focus on cutting emissions, because that's where humans have some control.

"If we control methane, which the U.S. is already starting to do, then we are likely to mitigate global warming more than one would have thought, so that's a very positive outcome," Shindell said. "Control of methane emissions turns out to be a more powerful lever to control global warming than would be anticipated."

Sources of methane include natural sources like wetlands, gas hydrates in the ocean floor, permafrost, termites, oceans, freshwater bodies, and non-wetland soils. Fossil fuels, cattle, landfills and rice paddies are the main human-related sources. Previous studies have shown that new rice harvesting techniques can significantly reduce methane emissions and increase yields.