Methane is the main component of natural gas and has a more potent short-term effect on climate change than carbon dioxide. The effect that the newfound emissions would have on climate change over 20 years, the Environmental Defense Fund said, would be similar to that of 37 coal-fired power plants.

The new study, led by researchers at Colorado State University, involves measurements of 114 natural-gas gathering facilities and 16 processing plants in 13 states.

Many gathering facilities use puffs of natural gas in valves that open and close to regulate gas or liquid flow, releasing a bit of methane into the air with every cycle. Anthony J. Marchese, a professor of mechanical engineering at Colorado State and the lead author of the new study, said that this practice surprised him. “I was: ‘Really? That’s what they do?’ ” he said.

Companies can substitute other relatively inexpensive technologies for the methane-leaking systems, he said, but “they’re so used to using gas pneumatic, and they think it’s so reliable, they are reluctant to change.”

The recognition of gathering facilities as a major source of methane leaks is an opportunity to look harder and fix them, and to upgrade to equipment that does not emit natural gas, Mr. Brownstein said. “None of this is rocket science,” he said. “Most of it is auto mechanics.”