HOUSTON (Reuters) - The U.S. oil and natural gas industry emits more methane than previously thought, U.S. Environmental Protection Agency Administrator Gina McCarthy said on Wednesday as she defended efforts to curb its output.

Environmental Protection Agency (EPA) Administrator Gina McCarthy announces steps under the Clean Air Act to cut carbon pollution from existing power plants during a news conference in Washington June 2, 2014. REUTERS/Joshua Roberts

The regulator last year said it would try to reduce emissions of methane, which is far more damaging to the environment than carbon dioxide, by requiring new oil and gas processing and transmission facilities to find and repair methane leaks and for producers to capture or limit methane from shale wells.

As part of that rules process, the EPA collected new data on how much methane is emitted by oil drilling, transportation and refining.

“Methane emissions from existing sources in the oil and gas sector are substantially higher than we previously understood,” McCarthy told IHS CERAWeek, the annual gathering of global oil executives, though she did not quantify the difference.

While the new data collected by the EPA on methane emissions show that emissions have not increased, they do give regulators a fuller picture of emissions, McCarthy said.

“The data confirm that we can and must do more on methane,” McCarthy said. “By tackling methane emissions, we can unlock an amazing opportunity to better protect our environment for the future.”

The Obama administration has also set a goal of reducing methane emissions 40 percent to 45 percent below 2012 levels by 2025.

So far, industry and state leaders have lined up to oppose McCarthy, who has sought industry’s help by asking them to voluntarily disclose their methane emissions.

Only eight out of nearly 8,000 U.S. natural gas producers have done so, and much of the EPA’s new data comes by combining research from other government agencies and universities.

SUPREME COURT

McCarthy told the conference she was disappointed that the U.S. Supreme Court temporarily put on hold federal regulations to curb carbon dioxide emissions from coal-fired power plants, but said she was confident the plan would ultimately be approved.

“We remain fully confident in the legal merits of this rule, and that ultimately, it will stand the test of time,” McCarthy said.

McCarthy did strike a bold note at the conference, seeking to project a sense of inevitability around the EPA’s proposed regulations in order to convince the oil and natural gas industry that it has no choice but to fall in line

“If anyone thinks we’re done on climate, think again, guys.”