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Even Without a Blowout, Gas Companies Leak a Lot of Methane Into the Atmosphere

Even on a good day, Southern California's natural gas infrastructure is a major greenhouse gas emitter.
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The boundary of Southern California Gas Company property, where Aliso Canyon Storage Field is located. (Photo: David McNew/AFP/Getty Images)

The boundary of Southern California Gas Company property, where Aliso Canyon Storage Field is located. (Photo: David McNew/AFP/Getty Images)

Over a nearly four-month span, gas poured out of a failed well in a storage field just north of the Porter Ranch neighborhood in Los Angeles. The well's operator, the Southern California Gas Company, wasn't able to plug the leak until about two weeks ago. As a result, the well released 97,100 metric tons of methane into the atmosphere, according to one recent estimate.

Just how bad is a 97,100-ton methane leak? Over the course of a century, that much methane would have the same warming effect as the annual emissions of 572,000 cars. The leak doubled the amount of methane the entire Los Angeles Basin releases into the atmosphere in a year.

Now, there are two ways of thinking about these numbers, and they aren't mutually exclusive. One: That's big. Two: The Los Angeles Basin releases a lot of methane—as much as a four-month leak out of the nation's fourth-largest natural gas storage field—even when nothing has gone wrong. "People tend to think, 'Oh, it's solved, now, right? They've stopped the leak. Yay!' No way," says Paul Wennberg, an atmospheric chemist at the California Institute of Technology. "It's about long-term emissions in the Los Angeles Basin."

Methane, the main component of natural gas, is a problem because it's a potent climate warmer. Methane isn't as prevalent as carbon dioxide, but it traps radiation much more effectively. Over the course of a century, one pound of methane in the atmosphere heats the planet 25 times more than one pound of carbon dioxide. In the Los Angeles Basin, methane comes primarily from landfills, cattle, and, most importantly, natural gas infrastructure that hasn't seen a dramatic blowout.

"Almost every time you have hydrocarbon production and infrastructure," says Thomas Ryerson, a chemist with the National Oceanic and Atmospheric Administration, "you can measure leaks out of them." Methane escapes during every step of the process as companies mine, refine, and pipe natural gas to customers. Companies in Southern California in particular seem to lose more methane, compared to their overall natural gas production, than companies elsewhere in the state, according to a 2013 study.

In other words, because of the way it's produced and shipped, natural gas is not as environmentally friendly of a fuel source as it may at first seem. California and the federal government are trying to amend that fact in various ways, such as requiring better leak-detection systems and placing a cap on the amount of methane a company can emit. The gas industry, however, opposes new regulations.

As bad as the Porter Ranch leak is, our everyday emissions aren't too pretty either.


"Catastrophic Consequences of Climate Change" is Pacific Standard's aggressive, year-long investigation into the devastating effects of climate change—and how scholars, legislators, and citizen-activists can help stave off its most dire consequences.