Carbon dioxide and methane emissions declined as oil and gas production rose across the U.S. between 2015-2022, according to a new study.
However, in the region that includes Pennsylvania, the story is different: Reported total emissions — carbon dioxide plus methane — have gone up by 4% as oil and gas production increased.
The study is based on data that companies report to the Environmental Protection Agency. It was conducted by Ceres and Clean Air Task Force, two non-profit advocacy groups, and Environmental Resources Management, a sustainability consultancy.
The drop in the total emissions across the U.S. is linked to state and federal policies that have been put in place since 2015, the study says.
In the Appalachian basin — the nation’s largest gas producing basin, which includes Pennsylvania — the rise in the total emissions comes from carbon dioxide.
That is typical when production surges and companies burn more fuel to run processes, explained Lesley Feldman, the research and analysis manager on the Clean Air Task Force’s methane pollution prevention team.
Feldman said to bring CO2 emissions down, the companies will have to electrify processes and cut down on flaring — burning of gas during oil extraction.
While carbon emissions have gone up, emissions of methane, a greenhouse gas with 28 times more heat trapping capacity than CO2, have gone down by 25% in the region.
Zachary Barkley, assistant professor at Penn State who works on using top-down or satellite-based methods to track methane emissions, said, “You have to take all EPA’s numbers with a grain of salt.”
Barkley, who was not involved with the study, said EPA uses an average estimate factor for each type of device a company has, and then scales up for the total equipment in the well. He said that would work if measurements were accurate and all devices were identical.
But when his research teams compared EPA’s numbers to what they were seeing from satellite measurements, they found “that the EPA was wrong from somewhere between 50-500%,” he said.
Feldman said the data also does not account for emissions from abandoned wells, and does not require companies to report large release events. She said that is “the main source of discrepancy between the reported and the measured emissions.”
In 2024, EPA finalized the New Source Performance Standards and Emissions Guidelines that it says is intended to regulate best practices among oil and gas drillers.
The agency said the revised reporting method will include large leak events, updated average estimate factors, and will incorporate direct measurement techniques. Barkley and Feldman both say the revisions can make the EPA data more accurate.
But there is still value in the existing EPA data, to compare companies to each other and to see if regulations have had an impact, Feldman said. “The data is not perfect, but at least it’s a good apples to apples comparison.”
Feldman noted the study shows variation among companies in emissions intensity, a measurement defined as greenhouse gas emitted compared to the amount of fuel produced.
“We’re seeing up to 32 times the difference in methane emissions intensity, between the highest and the lowest section of natural gas producers, which exemplifies the gap between companies using best practices and those that are not,” Feldman said.
The Marcellus Shale Coalition, which represents oil and gas companies, lauded the industry’s practices in reducing emissions.
“It’s clear these efforts are working to boost both the energy security of our nation” and fossil-fuel industry jobs, the coalition said in a news release.
The coalition cites steps companies are taking, such as improved leak detection and adopting electric drilling and fracking units.
Oil and gas basins in and around Pa. have the lowest methane intensity of all basins in the country, according to the study.
But, Feldman said, “there’s still a lot of emissions and this report is underestimating them. So, even though reported emissions may have come down, there’s still a lot of room. They can and should come down even further.”
This story is produced in partnership with StateImpact Pennsylvania, a collaboration among WESA, The Allegheny Front, WITF and WHYY.
