The researchers caution, however, that the study is only of a single – albeit significant – region during a specific period and cannot be projected nationally or beyond at this time. The larger and more hopeful message in the study, they say, is in the monitoring technology itself. Inexpensive and precise aerial rapid screening of methane leaks could be a proverbial game-changer for environmental monitoring.

“The technology has major implications for efforts to reduce greenhouse gas emissions,” said senior author of the study Adam Brandt, who is a professor of energy resources engineering in the School of Earth, Energy & Environmental Sciences (Stanford Earth) and director of Stanford’s Natural Gas Initiative. “These highly sensitive instruments can quickly and accurately pinpoint the relatively smaller number of high-consequence leaks and flag them for immediate repair.”

Major implications

Most methane is leaked from a handful of sources. In their study, the researchers found that fewer than 4 percent of surveyed sites produced half of all methane emissions observed. These are the super-emitters.

Regular flights over oil and gas producing regions would be more accurate and cost-effective than current approaches, Sherwin said, although some ground-based monitoring is still important for smaller emissions. Current ground monitoring of methane leaks costs about $600 per facility, according to industry estimates, and proposed Environmental Protection Agency (EPA) regulations would require this as many as four times a year. With more than 30,000 oil and gas assets and 15,000 kilometers of natural gas pipelines in the New Mexico Permian Basin, those costs could come to roughly $70 million annually.

“Per-site estimates for aircraft-borne sensing are significantly cheaper than that,” Sherwin said. The team has already begun discussions with regulators and the industry to encourage wider adoption of this type of sensing. The EPA proposal, which is based in part on a two-day methane detection workshop at which the authors were selected to present this work, would allow aerial screening six times a year with annual ground inspections, allowing producers to find and fix their big leaks faster at a lower total cost.

Brandt and colleagues strike an optimistic note. Once leaks are identified, shutting them down is often an inexpensive and straightforward fix. They hope these new monitoring techniques can be widely adopted to spot the super-emitters quickly, stop losing product and cut off damaging methane leaks as soon as possible.

Adam Brandt is also a senior fellow in Stanford’s Precourt Institute for Energy.

Additional authors are Elena Berman, Brian Jones, Matthew Gordon and Erin Wetherley from Kairos Aerospace, the company that developed the sensing technology, and Eric Kort of the University of Michigan.

The research was funded by the Stanford Natural Gas Initiative and the Alfred P. Sloan Foundation.

To read all stories about Stanford science, subscribe to the biweekly Stanford Science Digest.