Oil and gas wells in the US are releasing more methane into the atmosphere than had previously been thought, according to research led by the University of Michigan.

Methane is known to be a powerful greenhouse gas, but burning it off at oil and gas wells through a process known as ‘flaring’ was believed to effectively keep it from escaping into the atmosphere.

The US scientists found that ‘flaring’, the process used by the fossil fuel industry to limit the venting of natural gas from their facilities, is not as efficient has had been previously thought.

Outlining its findings, the researchers described how “industry and governments generally assume that flares remain lit and destroy methane, the predominant component of natural gas, with 98% efficiency.”


The study used “airborne samplings” across three areas responsible for over 80% of the US flaring activity and combined these observations with unlit flare prevalence surveys.

It found that flares were unlit approximately 3%-5% of the time and, even when lit, they were found operating at low efficiency.

“We find that both unlit flares and inefficient combustion contribute comparably to ineffective methane destruction, with flares effectively destroying only 91.1% of methane. This represents a fivefold increase in methane emissions above present assumptions and constitutes 4%-10% of total US oil and gas methane emissions, highlighting a previously underappreciated methane source and mitigation opportunity,” the researchers revealed.

The findings show that more methane is escaping from oil and gas wells and as a result, show there has been an underestimate of their contribution to overall methane emissions and climate change.

"There is a lot more methane being added to the atmosphere than currently accounted for in any inventories or estimates," said senior researcher on the study Professor Eric Kort.

The University of Michigan-led study on the methane emissions of the oil and gas industry is available here.