Jim Snyder (c) 2014, Bloomberg News.
WASHINGTON — Environmental groups are asking the Obama administration to beef up its climate plan by targeting methane leaks in the web of valves, pipes and pumps drillers use to produce and deliver natural gas.
While companies have a vested interest in keeping methane bottled up on its way to customers, some gas inevitably seeps out. That’s worrisome because methane — the primary component of gas — is 25 times more potent than carbon at trapping heat.
The administration has embraced gas as a cleaner alternative to coal because it produces about half the carbon dioxide when burned to generate electricity.
Conrad Schneider, advocacy director for the Clean Air Task Force, a Boston-based environmental group, said the United States won’t meet its own climate commitment to reduce greenhouse gases by 17 percent from 2005 levels by 2020 without targeting methane.
“It’s a very potent global warming pollutant,” he said. Regulating methane “could be the great capstone to their climate efforts,” Schneider said in an interview.
Clean Air Task Force, the Sierra Club, the Environmental Defense Fund and the Natural Resources Defense Council will send a letter urging the Environmental Protection Agency to regulate methane, both from natural gas and oil production. Natural gas is sometimes produced alongside crude.
The groups said technologies are available to cut methane emissions during oil and gas production by 50 percent in the next five years. They said the EPA and Interior Department should issue rules that will achieve the cuts.
Industry groups say new regulations aren’t necessary. While natural gas production is at record levels, methane emissions have fallen 11 percent since 1990, according to the EPA.
“The best science tells us that methane ‘leaks’ are not large enough to erode the environmental benefits of natural gas,” said Steve Everley, a spokesman for Energy In Depth, which promotes fossil-fuel development.
President Barack Obama’s EPA estimates about 30 million metric tons of methane was emitted in 2012, 9 percent of the total U.S. greenhouse gas emissions. Carbon accounted for a far greater share, or more than 80 percent.
While methane is more potent, it only remains in the atmosphere about 12 years, according to the EPA. Carbon lingers for decades. About one-third of the methane emissions come from oil and gas production and transmission.
EPA head Gina McCarthy told an industry group this month that the agency would decide before the end of the year whether the regulate emissions.
“The technology is there and we have the skills, brain power and tools to figure it out,” EPA spokeswoman Liz Purchia said in an email. “We just need to commit to get leaks out of system and capture them to deliver the benefits to consumers.”
She didn’t say whether the EPA would impose new rules or stick to voluntary efforts.
New rules that take effect at the start of the year targeting smog-causing pollutants will also reduce methane, though the gas isn’t specifically targeted.
A study by ICF International Inc. released earlier this year said companies could cut methane emissions relatively cheaply, at a cost of one cent per thousand cubic feet of natural gas.
Companies said costs are likely to be higher than environmental groups suggest, in response to white papers EPA released on methane emission leaks.
Sempra Energy, for example, said cost estimates for replacing seals on compressors, machines that increase pressure to push natural gas throughout the system, could be as much as $250,000, or more than triple the $75,000 EPA estimate.
In November, researchers published a paper in the Proceedings of the National Academy of Science that said methane emissions are probably 50 percent higher than EPA estimates.
The researchers measured methane in the atmosphere, drawing criticism from industry groups that said ground-level measurements are more reliable.
The magazine Science published a report by researchers at Stanford University, the Energy Department’s National Renewable Energy Laboratory, and other schools and scientific groups who measured levels in the air and on the ground.
It found that leaks, while likely higher than the EPA estimates, weren’t sufficient to erase natural gas’s climate advantage over coal.
“Natural gas can be a bridge to a sustainable energy future, but that bridge must be traversed carefully,” Garvin Heath, an NREL scientist, said in a statement when the study was published.
Rob Jackson, a professor of earth sciences at Stanford University who has studied methane emissions, said most gas wells don’t leak significant amounts. It’s important to quickly identify those that do, he said.
“A little bit of methane leakage goes a long way,” he said.