Ever since a father and son managed to draw four whiskey barrels of oil from a hand-dug hole near California’s Kern River 121 years ago, productive oil and gas wells have multiplied like mushrooms across the area. Though such wells are expected to emit minimal amounts of greenhouse gases during the oil-extraction process, scientists from a space-related research group were shocked by the size of the methane plumes they detected when they flew an infrared sensor over Kern County in 2015. Repeating the flights three more times in the next three years confirmed the initial reading: some wells were releasing at least six times more of the potent greenhouse gas into the atmosphere in one day than the Environmental Protection Agency had estimated they should emit in a year.

Karen Jones is one of the scientists at the Aerospace Corporation, the California-based nonprofit organization that conducted the aerial survey. She says she felt mystified by what she calls a lack of action among the oil fields’ operators and regulators as she watched the methane—the second-highest contributor to human-caused warming after carbon dioxide—continuously spew over the years. “The gas coming out of Kern County isn’t supposed to be there,” she says.

Revelations like Aerospace’s, which the nonprofit published in a report this past summer, are becoming more common. For years, oil and gas companies have been required to detect and repair methane leaks in their equipment. But scientists have produced dozens of studies over the past decade that suggest the current methods and technology used by industry to detect leaks—and by regulators to estimate how much methane is emitted—are inadequate to catch the actual scale of the problem.

Nonprofit groups and private satellite companies may soon make high-quality data about methane publicly available and ubiquitous, potentially creating more pressure to address the situation. Action to plug leaks and prevent further air pollution may be stymied in the meantime, though: the Trump administration took numerous steps that could weaken environmental protections, including rules outlining how companies monitor for and locate natural gas leaks in their equipment (methane is the main component of natural gas). Whether those rules will be reversed when the Biden administration enters the White House, and how long that process will take if it happens, remains to be seen.

Scientists say people of color and low-income communities, who already suffer disproportionately from the consequences of air pollution, will continue to bear much of the health brunt of such regulatory rollbacks. And more methane in the atmosphere is also likely to speed up the already accelerating process of global warming.

Eyes in the Sky

Using instruments on satellites and planes, researchers have, in recent years, revealed what they say are substantial inaccuracies in existing official methane emission counts. In 2014 a group of six scientists published a blockbuster study in Geophysical Research Letters exposing the largest U.S. methane anomaly that had ever been detected from space. The team calculated that the emissions around the hotspot—centered on the Four Corners region, where Arizona, Colorado, New Mexico and Utah meet—exceeded EPA estimates for the area and persisted for years in all seasons. The second-biggest emissions hotspot they identified was located near California’s San Joaquin Valley, home of most of Kern County.

Since 1990, the EPA has prepared an annual greenhouse gas inventory with the aim of estimating the emissions from all the country’s human-made sources. Based on typical emission rates some of the largest oil and gas companies have reported regarding their own infrastructure—such as individual pumps, valves and storage tanks—the EPA calculates what it expects the rest of the equipment in the industry to be giving off.

David Lyon, a scientist at the nonprofit Environmental Defense Fund (EDF), says the EPA may not have enough of the relevant data—and thus could underestimate the extent of leaks and other unexpected events. And because leaks spew many times more methane into the atmosphere than properly working equipment, missing such events would make the inventories wrong, says EDF’s chief scientist Steven Hamburg.

The EPA says it takes a comprehensive approach when estimating greenhouse gases in its inventories. “EPA’s emission estimates in the GHG [greenhouse gas] Inventory include the full range of conditions, including ‘abnormal events’ or ‘super-emitters,’” says agency spokesperson James Hewitt. “In addition, where data are available, emissions estimates for large anomalous leak events are estimated separately and included.” In response to subsequent questions, however, the EPA says that it “is correct that data are not available for every oil and gas emissions event from 1990 to recent years.... Given the variability of practices and technologies across oil and gas systems, it is possible that EPA’s estimates do not include all emissions from abnormal events.”

To check for possible differences between estimates and actual emissions, EDF researchers led a team of experts in amassing ground-based and airborne field measurements of methane coming from oil and gas facilities across the U.S. over a four-year period. In research published in Science in 2018, the group contended that in 2015 industry infrastructure emitted 60 percent more methane—at least an extra 4.9 million metric tons—than the EPA’s inventory estimate. That discrepancy is slightly less than the amount of methane emitted into the atmosphere by all the cattle in the U.S.

Part of the reason for the discrepancy may be the fact that oil and gas companies are only required to monitor emissions infrequently and with outdated technologies, according to several experts interviewed for this story. Since 2016 the EPA has required oil and gas operators in every state to search for methane leaks using handheld infrared cameras or devices that detect volatile organic compounds (VOCs). In Chevron’s oil fields in Kern County, employees inspect infrastructure with such devices “at least annually,” according to company representative Veronica Flores-Paniagua. But the cameras are expensive and can be imprecise, says Lee Fuller, executive vice president of the Independent Petroleum Association of America—a trade association and lobbying group for oil and gas producers. “If you see an apparent emission, one of the challenges is [that] it will show you there’s something coming out, [but] it doesn’t tell you what it is,” he says. Though the handheld cameras might show that a certain hatch should be closed or that a seal needs repair, “you don’t know how much it was emitting.”

“The purpose of leak detection and repair is to find and fix leaks, not to measure leaks,” Flores-Paniagua says. “If emissions sources are identified, they can generally be repaired without measurement.”

Fuller also suggests that the requirement to use the devices discourages businesses from considering more accurate data from sources such as airborne sensors and satellites. “Even if you do that, you still have to do the old technology as well,” he says. “So it’s a double cost instead of a single cost.”

Despite expressing support for efforts to minimize methane leaks last year, EPA administrator Andrew Wheeler announced in August that he had signed two rules that significantly reduced requirements for oil and gas operators to monitor infrastructure that could be leaking. In 2016 the Obama administration’s EPA had decided to start regulating methane separately from other kinds of air pollution, and it added requirements for checking transmission and storage facilities for natural gas—infrastructure known to be leak-prone. Wheeler’s changes undo both steps. Though semi-annual monitoring of fugitive emissions at wells and compressor stations will continue to be required, the 2020 changes remove the need for monitoring transmission and storage infrastructure—and for methane to be regulated separately. Because “pollution controls used to reduce VOC emissions also reduce methane emissions,” according to the EPA, the agency now indicates that distinct methane regulation is unnecessary.

This development has sparked legal pushback from environmental groups and some objections from leaders in the oil and gas industry. They include Gretchen Watkins, president of Shell Oil Company, who said in an interview with NPR that she was frustrated to hear the news because the negative impacts of leaks and fugitive emissions are well known. But the EPA’s Hewitt says the reversal could actually streamline the application requirements for using emerging technologies—including airborne sensors and satellites. “The EPA recognizes that new technologies that are expected to enter the market could help locate the source of fugitive emissions sooner and at lower costs than the current technologies required,” he says.

Still, that potential (and small) silver lining is unlikely to negate concerns about the health and environmental side effects of the rule change or the avalanche of other environmental regulatory rollbacks announced this past summer. The latter include the EPA altering how it creates rules on air pollution, as well as historic deregulation of the National Environmental Policy Act—which governs reviews for thousands of federal agency programs, such as drilling projects. The incoming Biden administration could seek to reverse these policy changes, though some could take years to redo through the federal regulatory bureaucracy.

An analysis from the Rhodium Group, an independent research outlet, found that the recent rollbacks of methane regulations by the EPA and the Bureau of Land Management would cause oil and gas facilities to release an extra 592 million metric tons of methane by 2035. That would be bad news for everyone’s health. In addition to its role in hastening global warming, methane contributes to ground-level ozone (the main ingredient in smog), which can harm the lungs. And burning methane, like any fossil fuel, produces chemicals that form particles of pollution that are a risk factor for many serious diseases, including asthma, Alzheimer’s and Parkinson’s. (Though burning methane produces less of these than coal or oil.) The VOCs that are emitted, along with methane, from oil and gas infrastructure have been shown to damage major human organs and cause cancer.

More methane emissions would be particularly harmful for already disadvantaged groups. Nationally, average concentrations of air pollutants in the homes of people of color are sharply higher than those recorded in the homes of white people. Black Americans are 75 percent more likely to live in communities next to industrial facilities whose operation directly affects them in some way. Exposure to concentrated amounts of methane itself can cause headaches, dizziness, loss of consciousness, nausea and vomiting, and general weakness. “We’re talking about real people living along the fence line where leaks are wafting over,” says Timothy O’Connor, a senior attorney at EDF and a former inspector of industrial facilities in California.

Nowhere to Hide

Meanwhile some states have been experimenting with aerial technology projects to better monitor methane emissions. In partnership with the California Air Resource Board (CARB), one of the agencies involved in enforcing the state’s pollution rules, scientists from NASA’s Jet Propulsion Laboratory (JPL) mapped most of California’s methane-emitting infrastructure with an airborne sensor from 2016 through 2018. Their research, published last year in Nature, found that 0.2 percent of California’s methane-emitting infrastructure—from the oil and gas, dairy and landfill industries—contributed at least a third of the state’s total methane emissions. This result indicates that abnormal activity adds significantly to total methane counts. The JPL researchers (who were not affiliated with the Aerospace Corporation) found a number of leaks and malfunctions in the Kern County area, says the study’s lead author Riley Duren of JPL.*

CARB is now exploring a new collaboration with Planet, a company that owns satellites that provide daily images of the Earth. Through NASA’s Carbon Monitoring System, scientists have conducted methane surveys in Texas, Mexico, California, Utah, Colorado and Arizona and are planning to conduct more in California, Louisiana, Colorado and the Gulf of Mexico. But nowhere in the country have oil and gas companies or their regulators expanded these kinds of pilot programs to the extent needed to adequately measure emissions at scale, Duren says. “Even in California, there are gaps,” he adds. The Independent Petroleum Association of America’s Fuller says gaps may result from the fact that regulators are limited by the current legal structure and need time to test the reliability and cost of the technologies for more widespread applications.

Such piecemeal efforts may be superseded by 2022, when EDF plans to launch a satellite that it says will collect unprecedented global data on changing methane emissions from oil and gas infrastructure on a regular basis. The group plans to provide those data for free on a publicly accessible platform. In September GHGSat, a satellite company that sells the information it collects, launched another of its methane-tracking satellites into space and promised that satellite would deliver 100 times higher resolution than similar products. Scientists are excited by these tools. “The eye-in-the-sky approach will ultimately solve this problem,” says Rob Jackson, an ecologist and professor at Stanford University, who has authored multiple studies tracking methane emissions. “There'll be nowhere to hide.”

*Editor's Note (12/22/20): This paragraph has been updated to more accurately reflect the distribution of methane emissions in California.