Oil and gas firms 'have had far worse climate impact than thought', 19 February 2020.

The oil and gas industry has had a far worse impact on the climate than previously believed, according to a study indicating that human emissions of fossil methane have been underestimated by up to 40%...In the past two centuries, the amount of methane in the atmosphere has more than doubled, though there has long been uncertainty about whether the source was biological – from agriculture, livestock or landfills – or from fossil fuels...

Earlier estimates were based on intermittent, bottom-up monitoring of oil and gas companies and comparisons with geological evidence from the end of the Pleistocene epoch, about 11,600 years ago. For a more accurate comparison, a team at the University of Rochester in the US examined levels of methane in the pre-industrial era about 300 years ago...The findings, published in Nature, suggest the share of naturally released fossil methane has been overestimated by “an order of magnitude”, which means that human activities are 25-40% more responsible for fossil methane in the atmosphere than thought.

This strengthens suspicions that fossil fuel companies are not fully accounting for their impact on the climate...An earlier study revealed methane emissions from US oil and gas plants were 60% higher than reported to the Environmental Protection Agency. Accidents are also underreported. A single blowout at a natural gas well in Ohio in 2018 discharged more methane over three weeks than the oil and gas industries of France, Norway and the Netherlands released in an entire year...Fracking also appears to have worsened the problem...

The lead author, Benjamin Hmiel, said the paper was cause for optimism because it showed that action on methane – which has a relatively short shelf life, persisting in the atmosphere for about nine years – could give a strong short-term boost to efforts to stabilise the climate...