A new NASA-sponsored study shows that global methane emissions produced by livestock are 11 percent higher than estimates made last decade. Because methane is a particularly nasty greenhouse gas, the new finding means it's going to be even tougher to combat climate change than we realized.

We've known for quite some time that greenhouse gases produced by cattle, sheep, and pigs are a significant contributor to global warming, but the new research, published in Carbon Balance and Management, shows it's worse than we thought. Revised figures of methane produced by livestock in 2011 were 11 percent higher than estimates made in 2006 by the Intergovernmental Panel on Climate Change (IPCC)—a now out-of-date estimate.

It's hard to believe that belches, farts, and poop from livestock could have any kind of global atmospheric effect, but it's an issue of scale, and the nature of methane itself.