Quartz: Does natural gas really cause less global warming than coal? We’re about to find out

The hydraulic fracturing (“fracking”) of rocks deep underground to extract their tightly held reserves of oil and gas is controversial for its impact on the environment, particularly water sources. But it’s been an article of faith that the ensuing boom in natural gas production is good for climate change. Natural gas-fired power plants emit about half as much carbon dioxide as coal.

But there’s a wild card. It’s methane, a byproduct of the production and use of natural gas. Over a 100-year period, methane in the atmosphere traps over 20 times as much heat as the same weight of carbon dioxide. And no-one really knows how much methane is escaping at the thousands of production wells sprouting across the US. So no-one knows the break-even point at which these fugitive methane emissions from natural gas exceed the carbon savings from replacing coal.

A paper published last year by the Proceedings of the National Academy of Sciences (PNAS) said that better data were needed. “There have been all these studies that have come out about the emissions rates for all parts of natural gas production but none of them were based on going out and actually measuring the emissions,” says Fred Krupp, president of the Environmental Defense Fund (EDF). “Having a debate about fracking without real data is silly.”  MORE