Methane emissions from the oil and gas sector held steady in the United States even as oil and gas production increased during a recent period of heightened regulations, according to new research from Johns Hopkins University.
One reason: companies have built more infrastructure needed to better capture methane—a vital component of natural gas—and transport it for sale as fuel, providing a financial incentive to limit the amount escaping into the atmosphere.
The study, published in Communications Earth & Environment , is part of an effort to determine whether federal greenhouse gas legislation and mandates have meaningfully decreased methane emissions.
"This is a good news/bad news situation. The good news is that emissions have not markedly increased, as many scientists feared would happen after an enormous increase in natural gas production in the decades following the hydraulic fracturing boom," said senior researcher Scot Miller , an associate professor of environmental health and engineering at Johns Hopkins University who studies greenhouse gases. "The bad news is that oil and gas production is still a large percentage of U.S. methane emissions, and we do not find any evidence that a flurry of federal legislation had an impact on emissions."
Nearly 30 times more potent and with a shorter lifespan than carbon dioxide, methane is widely regarded as the second most important greenhouse gas to target for emissions monitoring and reduction, Miller said.
In 2021, the Environmental Protection Agency restarted the process of developing rules to address methane emissions under the Clean Air Act. Congress later enacted the Inflation Reduction Act of 2022, which established fees for methane emissions from oil and gas facilities and allocated more than $1 billion in technical support to the oil and gas sector. While short-lived, the regulations were an unprecedented push towards reducing one of the major contributors to climate change, the researchers said.
To assess the efficacy of the policies, the researchers combined satellite data with atmospheric modeling to estimate where emissions from the oil and gas sector occurred in the U.S. and how large they were for the years bookending the legislative activity: 2019-2024.
The researchers used data from Europe's space-based TROPOMI instrument and GOSAT satellite, which observe the amount of methane in the air at many locations across the globe. Then, because methane can be blown around by wind and other elements, the researchers developed an algorithm that traced the gas in the atmosphere back to its sources on the ground.
Total methane emissions from oil and gas activities for the contiguous U.S. remained between 9.3 teragrams to 10.4 Tg each year. Emissions decreased by 0.58 Tg from 2019-2023, but rose slightly from 2023-2024.
However, the intensity of emissions—the amount of methane emissions relative to oil and gas production—decreased by about 11%, representing the continuation of a decades-long trend rather than a significant drop in emissions, the researchers said.
"We don't see a detectable decrease in emissions after the Inflation Reduction Act," said Ao Chen, a PhD student at Johns Hopkins and first author of the paper. "Of course, there's no way to test the counterfactual. It's possible that without the Inflation Reduction Act, methane emissions would be much higher."
The gradual decrease in emissions intensity may reflect better industry practices as methane transitioned from a side product of oil extraction to a valuable consumer product, the researchers said. When there is no pipeline to bring natural gas from the well to market, drilling companies have less incentive to prevent leaks and instead flare the gas to get rid of it. When pipeline infrastructure became available in regions like West Texas, that gas moved to market, and consumers began using it for heating, cooking, powering certain appliances and generating electricity. Evidence from other studies suggests that leaks decline when gas becomes a valuable commodity.
Additionally, oil and gas companies have been updating and improving their infrastructure.
"Better industry protocols and less flaring have likely helped gradually curb emissions intensity even as gas and oil production have increased," Miller said.
Further analysis showed that emissions declined in some states over the same period. Texas, home to the largest oil producing basin in the country, saw a 14% decline in oil and gas methane emissions.
California and Colorado, by contrast, are likely falling short of their emissions reduction goals, the researchers said.
"Without long-term regulatory durability, however, the industry may lack the incentive to further reduce methane emissions," said Chen. "While curbing emissions intensity is a step in the right direction, there needs to be a reduction in the total methane emissions to really have an impact."
