Study Reports Largest Methane Leak in US History

UC Davis, in a joint study with the National Oceanic and Atmospheric Administration, revealed that last year’s Aliso Canyon gas leak was the largest methane blowout in United States history. Their findings were published in the Feb. 25 edition of the research journal “Science.”

Stephen Conley, co-lead scientist from UC Davis, flew his aircraft over the Aliso Canyon area after the leak was sealed on Feb. 11 and described to the UCSD Guardian the readings he found as being a cause for concern. Not only is the methane release the largest leakage recorded, but it also has implications that extend beyond California’s borders.

“[The methane readings were] from two to 60 parts per million,” Conley stated. “[This is] about 20 times the next largest leak we’ve seen. The escaped gas is now continuing its journey around the world. Beyond the short-term potential health issues, this isn’t an Los Angeles or California problem — it’s a global issue.”

According to Thomas Ryerson, the co-lead scientist from the NOAA, the accidental leakage that took place last October has had adverse consequences, affecting both people and the environment.

“This leak displaced thousands of people, causing acute health problems,” Ryerson told the Guardian. “It released 97,100 metric tons of methane, a powerful greenhouse gas into the atmosphere … [affecting] climate, air quality and human health.”

Ryerson spoke about the state’s efforts to reduce the impact of automobiles on climate change. These measures involve enhancing the standard fuel economy and endorsing the use of greener transportation practices.

“Significant effort and expense has been spent in California over the years to minimize greenhouse gas emissions,” Ryerson said. “[These include] improving fleet gas mileage, promoting hybrid and electric vehicles [and] supporting alternative and public transport.”

In spite of these efforts, the methane leak, before its containment on Feb. 11, produced a volume of greenhouse gas comparable to the amount of methane released from 527,000 cars in the U.S. annually.

Ryerson clarified that the impact of the gas leak not only neutralizes Californian efforts exerted to combat climate change, but also sets the initiative back even further.

“It will take even more effort to compensate for the effects of this leak and ensure that we are better prepared for any future accidental releases,” Ryerson said.

Conley’s data collection methods are a major takeaway from this experience, according to co-author Donald Blake. The availability of an aircraft to capture measurements is invaluable in keeping track of changes in the atmosphere, especially damaging ones.

“It was important to have Steve’s plane fly around the area so estimates of leak rate could be made,” Blake told the Guardian. “I think having this type of aircraft sampling is important, and I would like us to have such capability on standby in the event something else happens like this.”

Conley believes that the next step people need to take in order to reduce climate change is to decrease the use of fossil fuels; unless that measure is taken, methane gas will continue to pose a threat.

“Hopefully, [people will] get a little more serious about moving away from fossil fuels,” Conley said. “We need to accept that as long as we have natural gas heated homes, we’ll need to store and transport methane, and we’ll continue to have leaks.”