Satellites that sweep over the north of the energy-rich state can spot the gas as it escapes from drilling rigs, compressors and a pipeline snaking across the badlands. In the air it forms a giant plume: a permanent methane cloud, so vast that scientists questioned their own data when they first studied it three years ago. “We couldn’t be sure that the signal was real,” said Nasa researcher Christian Frankenberg.
The United States’ biggest methane “hot spot”, verified by Nasa and University of Michigan scientists in October, is only the most dramatic example of what scientists describe as a $2bn leak problem: the loss of methane from energy production sites across the country. When oil, gas or coal are taken from the ground, a little methane – the main ingredient in natural gas – often escapes along with it, drifting into the atmosphere where it contributes to the warming of the Earth.
Methane accounts for about 9% of US greenhouse gas emissions, and the biggest single source of it – nearly 30% – is the oil and gas industry, US government figures show. All told, oil and gas producers lose 8m metric tons of methane a year, enough to provide power to every household in the District of Columbia, Maryland and Virginia.