US oil and gas facilities are pumping out four times more planet-warming methane gas than estimated by regulators.
Data published by the Environmental Defense Fund on Wednesday estimates leaks, flaring and venting of methane at US onshore oil and gas operations at 7.5mn tonnes per year — enough wasted gas to meet the annual energy needs of more than half of American homes.
Shell, BP and ExxonMobil did not respond to a request for comment.