A study in the journal Science finds that the United States is putting a lot more methane, a potent contributor to global warming and the primary compound in natural gas, into the air than the Environmental Protection Agency has estimated. But the report also shows that the problem is fixable – and not a reason to shut down the controversial extraction method known as fracking. Natural gas, as a transitional fuel, remains an important response to climate change.
Methane is a powerful driver of climate change. Unburned methane is about 20 times more effective at heating the planet than carbon dioxide on a century-long time frame. Burning it, on the other hand, is much better for the environment. So burning methane could help reduce U.S. greenhouse emissions in the short term, but letting lots of it waft into the air would have a negative effect on the climate.
The studys results arent disastrous, for two reasons. First, they indicate that extremely high estimates of methane leakage that have popped up in analyses of particular regions arent representative of the leakiness of the whole natural-gas system. Second, a lot of the leakage can be reduced relatively easily.
The EPA has already established rules requiring drillers to perform green completions, which capture methane escaping from wells. But that rule only applies to new wells, and not even to all of those. Besides, significant leakage occurs not only during drilling but also during fuel processing, storage and transportation.
Reasonable new regulation wouldnt be very expensive, in part because it would reduce the amount of product that goes to waste. The Science analysis, meanwhile, indicates that a huge chunk of the countrys methane pollution comes from a small group of super-emitters, which the EPA could aim to fix first.
Even with current levels of leakage, the researchers note, replacing coal-fired power with natural-gas electricity generation is a net positive for the climate, though the world eventually has to transition off natural gas, too.
But that finding shouldnt deter Americans from expecting to waste less fuel, reducing local ozone pollution and gaining more emissions benefits in the process.