Methane leaks during the extraction of natural gas could make the fuel a larger contributor to global warming than coal generation.

That’s according to new research from the Journal of Geophysical Research, which suggests although burning natural gas only produces about half as much carbon dioxide per unit of energy as coal, the methane contained within it is around 86 times more damaging to the climate if it leaks out in its raw form.

Researchers used a Cessna 402B research aircraft to quantify methane emissions from a 4,235-square-kilometre region of the Marcellus Formation of Pennsylvania and West Virginia, which accounts for about 40% of total US shale gas production.

They compared air samples taken over six flights in 2015 and 2016 to background measurements, factoring in other sources such as cattle farms, coal mines and landfills.

The leak rate from natural gas extraction operations in the sampled area was judged to be around 3.9% of the total production, higher than 2.4%, which is where researchers say emissions are more potent than from coal-fired power.

The study claims this issue could negate any climate benefits derived from switching fuels and says more stringent regulations are needed to capture methane emissions.