(Bloomberg) -- Methane leaks are making the climate crisis worse faster, but companies and investors still find them hard to trace.

Legal & General Investment Management, the $1.4 trillion British asset manager, on Thursday said it will push energy companies to have “zero tolerance” for methane leaks -- for a start, by measuring leaks from oil and gas wells.

“Standards on methane-leak disclosure are not strong,” said John Hoeppner, head of U.S. stewardship and sustainable investments at LGIM. “Every company can report leakages in the way that makes them look good versus their peers.”

It’s hard to know how big the problem is when companies differ so widely on whether they report volume or frequency of leaks, he said.

A focus on methane might be one of the fastest ways to fight global warming. Methane that escapes from pipelines and other oil-processing facilities has been blamed for as much as 25% of the planet’s global warming. It’s one of the most harmful greenhouse gases because, over a 20-year period, it traps about 86 times as much heat as carbon dioxide does.

Investors are broadly focusing on improving climate-related disclosures from companies, but have grown more concerned about methane in particular as President Donald Trump’s administration has sought to abandon regulations around monitoring and controlling leaks.

LGIM wants companies to pay extra attention to consistent, comparable methane-leak measurement and whether oil and gas companies are availing themselves of new monitoring tools like satellite technology, sensors, drones, sniffers and detectors. In cooperation with the Environmental Defense Fund, the investor is issuing a report Thursday that details best practices on methane-leak measurement. They plan to distribute the guidelines to oil and gas companies.

“Over a dozen major oil and gas companies have committed to ambitiously reduce their emissions, but they’ve got to prove that they are doing it,” said Tom Murray, vice president of the EDF’s unit focusing on sustainable business practices. He said companies’ methane-emission estimates now are sometimes off by as much as 60%.

Natural gas, which is chiefly methane, is a useful transitional tool in the energy mix, especially for its ability to replace coal. However, Hoeppner says, its future depends on whether the industry gets control of methane leakage. The oil and gas industry leaks about 3.2 percent of the natural gas it produces, according to BP Plc, which has been installing permanent methane-leak detectors on its new projects.

To contact the reporter on this story: Emily Chasan in New York at echasan1@bloomberg.net

To contact the editors responsible for this story: Tim Quinson at tquinson@bloomberg.net, Philip Gray

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