Exxon Mobil vows to reduce emissions of methane, a potent greenhouse gas, from its natural gas drilling operations.
But company officials have declined to put a figure on how much they can or will reduce emissions, making the energy giant's public commitment difficult, if not impossible, to gauge.
Exxon said Monday that it would improve detection of methane leaks and repair equipment causing the leaks across its XTO Energy natural gas subsidiary.
XTO President Sara Ortwein said the company would provide new training for workers and install new equipment that uses compressed air instead of natural gas to run pneumatic equipment in the field. She and another Exxon official said the company is assessing the use of planes, satellites and drones mounted with optical gas-imaging cameras to hunt for methane leaks.
Ortwein said, however, that it was too early to say how much the company's measures would reduce leaks, and she declined to say how much Exxon would spend on the effort.
Methane is the main component of natural gas and is a far more powerful heat-trapping gas than carbon dioxide, making reduction of methane leaks a key goal of environmentalists to address the causes of climate change. About 40 percent of manmade emissions of methane in the U.S. come from the production and use of natural gas, coal and oil. Exxon is the second-largest U.S. emitter of methane from onshore wells, although many smaller companies release more methane per well, according to a 2016 study of federal data by the Center for American Progress.
The oil and gas industry has lobbied furiously against federal requirements proposed under President Barack Obama that would require them to monitor, report and stop methane leaks. The companies argue that federal regulations would be burdensome and aren't needed because they are already working to cut emissions.
Many environmentalists argue that voluntary measures aren't enough, and that the industry vastly underreports how much methane it leaks.
The energy industry is eager to portray natural gas as a relatively clean-burning fossil fuel, and its use in place of coal to produce about one-third of the nation's electricity has helped reduce U.S. emissions of carbon dioxide.
"As long as there are questions about methane emissions, it clouds people's perception of whether it really is ... cleaner than coal," said Michael Maher, a longtime Exxon economist now at a public policy institute at Rice University.
Exxon's announcement comes as the fate of federal regulation of methane emissions by the energy industry is uncertain.
This year, the Environmental Protection Agency under President Donald Trump tried to suspend Obama administration rules on emission standards for oil and gas wells. In July, however, a federal appeals court stalled the move, ruling that EPA could rewrite the rules but couldn't block the 2016 regulations in the meantime.
Shareholders have put pressure on Exxon, the nation's largest producer of natural gas, to confront the methane problem. At this year's annual meeting, a resolution asking the company to report annually on what it was doing to minimize methane emissions was supported by holders of 39 percent of the company's shares despite board opposition to the measure.
Matt Watson, a methane expert at the Environmental Defense Fund, which was briefed by Exxon before its announcement, praised the company for targeting the highest emission sources and promising to upgrade existing equipment rather than focusing only on new facilities. He said it would "help position Exxon and XTO as a real leader" in controlling methane, even though other energy companies have taken similar steps.
Watson said most operators in Colorado, including Anadarko, Noble and Cana, have put similar measures into place since the state imposed stricter methane rules on energy companies two years ago.
"This isn't radical new stuff," Watson said. "The technology and the field practices for reducing emissions have been out there for some time, and leading companies have been using them."