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Methane is what many people use to cook with. It is also what rises from landfills and also from the stomachs of cows. Unfortunately, when methane gas reaches the atmosphere, it warms the planet. As NPR's Christopher Joyce reports, research out today reveals new details about how much methane is coming and from where.
CHRISTOPHER JOYCE, BYLINE: Methane, pound for pound, is one of the most powerful greenhouse gases. So scientists measure how much is going up into the atmosphere.
STEFAN SCHWIETZKE: We know sort of how big the pie is, how large of the total emissions.
JOYCE: Stefan Schwietzke is an atmospheric scientist at the University of Colorado.
SCHWIETZKE: What we're really trying to figure out now is how large are the individual slices.
JOYCE: How much from oil and gas wells and pipelines, how much from rotting landfills, rice paddies, the stomachs of cows. They all produce methane. But scientists have learned to identify certain chemical signatures that distinguish each source. Schwietzke's research team combed through reams of studies that did this. And they were surprised to find that much more methane bubbles up naturally from underground than people realized. But also surprising was what's coming from oil and gas operations.
SCHWIETZKE: The manmade portion of that, we found it's 20 to 60 percent larger than previously thought.
JOYCE: That's everything from leaking gas wells and storage tanks to pipelines. This is in spite of the fact that the oil and gas industry has reduced leaks from its operations over the past three decades. Schwietzke notes that while the industry has cleaned up its operations, there are simply more wells and pipelines than ever. The findings, published in the journal Nature, confirm other recent studies about methane sources. The Environmental Defense Fund has been involved in many of these studies. Steve Hamburg is EDF's chief scientist. He says knowing the source makes it easier to plug.
STEVE HAMBURG: The bottom line implications are that it's a real opportunity to reduce methane emissions from oil and gas operations, and it will have an important positive effect on the climate.
JOYCE: That may not end the problem, though. Scientists know there's been an increase in the amount of methane in the atmosphere. And globally, Schwietzke found that most of that uptick is not from oil and gas. It seems to be coming from the land.
SCHWIETZKE: Could it be that the increase in agricultural output is responsible for that, or is it because of a warming climate that wetlands are responding to that and they're increasing emissions?
JOYCE: Schwietzke says that's the next part of the methane puzzle to figure out. Christopher Joyce, NPR News. Transcript provided by NPR, Copyright NPR.