A new study says that U.S. emissions of the greenhouse gas methane, often emitted by farm and energy operations, are much larger than previously estimated.
"Methane is the source of the gas we burn in stoves. You can also use it to make plastics, antifreeze or fertilizer. It comes out of underground deposits, but it also seeps up from swamps, landfills, even the stomachs of cows.
And while methane is valuable, a lot of it gets up into the atmosphere, where it becomes a very damaging greenhouse gas.
Scientists have been trying to find out, with varying success, exactly how much of this climate-warming gas gets into the atmosphere. A published in this week's issue of the Proceedings of the National Academy of Sciences, suggests there's much more up there than previously thought."