Why we’re still so incredibly confused about methane’s role in global warming

By Chris Mooney, Washington Post.

It’s perhaps the most contentious issue in U.S. climate change policy right now: How can we deal with emissions of methane, a powerful if short-lived greenhouse gas, which has many sources but appears to be leaking into the air in considerable volumes from U.S. oil and gas operations?

The Obama administration is expected to release methane regulations for new sources of emissions very soon, and the EPA recently revised upwards, considerably, its estimates of how much methane is leaking into the atmosphere from the U.S. energy industry. And yet at the same time, there remains considerable scientific uncertainty and debate over just how much methane the U.S. is emitting and how much that has changed due to the current oil and gas boom — and over what those emissions even mean.

A new study in Nature Climate Change, for instance, gets at why understanding the importance of methane can be such a difficult, confusing affair. In particular, it takes issue with some of the math that has often been used to compare the consequences of emitting methane with the impact of the chief, long-lived global warming gas, carbon dioxide. And it finds that really, we may not even know how important our methane emissions are in the first place until we also know how quickly we’re able to get carbon dioxide under control.