But figuring out where methane emissions are coming from is a major challenge. The colorless, odorless gas has proved difficult to measure at the source of leaks without nearby access to the sites . Early attempts by the Environmental Protection Agency to determine the scope of the problem significantly underestimated emissions.

Methane leaks are relatively inexpensive to fix, and stopping leaks allows energy companies to sell more gas. The International Energy Agency has estimated that as much as 50 percent of the 84 million tons of methane emitted by the oil and gas industry every year — from leaky wells and pipes and other causes — “can be mitigated at no net cost, because the value of the captured methane could cover the abatement measures.”

The Environmental Defense Fund has worked for many years on methane issues; it organized a five-year, $20 million research effort into leaks in the United States across the production and supply network. That research, which helped the E.P.A. adjust its national emissions estimates, involved local measurements from ground instruments and airplane flyovers. But such methods are not always feasible — or welcomed — in other countries.

To address the problem of finding leaks around the world, a recent report from the National Academy of Sciences called for methane monitoring from space, where international access is not a problem. “Satellite measurements are critical,” said David T. Allen, a professor of chemical engineering at the University of Texas who served on the committee that wrote the report. “Right now satellite measurements are one area in which we have very limited information.”

Some government-launched science satellites do monitor methane, but their instruments lack the resolution to pinpoint sources on the ground. Some commercial ventures also detect methane from space, but their data is proprietary.