US oil, gas industry emits 60% more methane than thought: Study

CRUDE-OIL

The US oil and gas industry emits 13 million metric tonnes of the potent greenhouse gas methane from its operations each year, 60 per cent more than estimated, scientists say. A study, published in the journal Science, found that most of the emissions came from leaks, equipment malfunctions and other "abnormal" operating conditions.

The climate impact of these leaks in 2015 was roughly the same as the climate impact of carbon dioxide emissions from all US coal-fired power plants operating in 2015, researchers found.

"This study provides the best estimate to date on the climate impact of oil and gas activity in the United States," said Jeff Peischl, a scientist working in US National Oceanic and Atmospheric Administration (NOAA)'s Chemical Sciences Division.

Researchers including those from University of Colorado Boulder and University of Texas Austin in the US assessed measurements made at more than 400 well pads in six oil and gas production basins and scores of midstream facilities; measurements from valves, tanks and other equipment; and aerial surveys covering large swaths of the US oil and gas infrastructure.

Methane, the main ingredient of natural gas, is a potent greenhouse gas that has more than 80 times the warming impact of carbon dioxide over the first 20 years after its release.

The new study estimates total US emissions at 2.3 per cent of production, enough to erode the potential climate benefit of switching from coal to natural gas over the past 20 years.

The methane lost to leakage is worth an estimated USD 2 billion, according to the Environmental Defense Fund, enough to heat 10 million homes in the US.

The assessment does suggest that repairing leaks and addressing other conditions that result in the accidental release of salrable methane could be effective.

"Natural gas emissions can, in fact, be significantly reduced if properly monitored," said Colm Sweeney, an atmospheric scientist in NOAA's Global Monitoring Division.

"Identifying the biggest leakers could substantially reduce emissions that we have measured," said Sweeney.