Stories

Natural gas boom: Methane emissions are far higher than EPA says

Researchers examine methane emissions from an oil or gas facility.
Methane researchers in the field. Photo: EDF

A new study out today in the journal Science finds that methane emissions from the U.S. oil and gas industry are nearly 60% more than current EPA estimates.

Why it matters: With natural gas now the dominant fuel for generating electricity in the U.S., determining its environmental footprint is crucial. Although burning natural gas for energy emits fewer long-lived greenhouse gases, it does release considerable amounts of methane — a potent, short-lived global warming agent.

The background: During the past decade, as the U.S. energy market has increasingly favored natural gas as a power source over coal — think of the "fracking" boom that transformed the landscape in several states — numerous studies have attempted to estimate its climate change ramifications.

What they found: Using ground-based measurements as well as data gathered from aircraft, researchers found that the current leak rate from oil and gas operations in the U.S. is 2.3%, compared to the EPA's estimate of 1.4%.

  • The volume of natural gas lost during its production could fuel 10 million homes, according to an Environmental Defense Fund press release.
  • The study, which represents the largest effort yet to quantify methane emissions from oil and gas operations, states such gas is worth $2 billion, giving the energy industry an incentive to act.

The big picture: Methane can have more than 80 times the global warming impact of carbon dioxide during the first 20 years after its release, though it declines after that.

What they're saying: "Emissions across the supply chain are large enough that they essentially double the footprint of natural gas combustion over a 20-year timeframe,” Ramon Alvarez, the lead author of the study and associate chief scientist at EDF, told Axios.

  • Study co-author Amy Townsend-Small of the University of Cincinnati described to Axios via email how methane emissions could negate progress on CO2 cutbacks:
"In the U.S., carbon dioxide emissions have decreased recently for a few reasons, one of which is a reduced reliance on coal for electricity generation.  But if that is accompanied by an increase in methane emissions from the natural gas supply chain and/or other anthropogenic and natural sources, it could cause rapid climate warming with potentially devastating impacts."

Yes, but: Robert Howarth of Cornell University says the new study could suffer from "a severe underestimate of the importance of methane emissions from the U.S. natural gas sector." Howarth, who was not involved in the study, tells Axios:

  • The study relies too heavily on direct measurements taken at energy facilities and then extrapolated to the energy industry more broadly.
  • By inferring aggregate emissions across large areas using planes, satellites and monitoring towers, Howarth says emissions estimates are even higher.
  • He says it also ignores emissions that occur during drilling, which other studies have found to be particularly high.

The bottom line: With deregulation all the rage in Washington, it may be up to the energy industry to clamp down on their methane emissions due to the monetary incentive involved. BP recently set a methane target for the first time, and ExxonMobil said it would cut methane emissions and has come out in favor of federal regulation.