(Washington) Natural gas flaring, which burns excess gas from oil and gas wells, releases five times more methane, a potent greenhouse gas, than previously estimated, according to a study published Thursday in Science.
Posted at 9:28 p.m.
As a result, this practice has a much greater impact on climate change with, between announced and actual gas flaring across the United States, a warming potential equivalent to introducing 2.9 million additional cars each year, specifies the scientific document.
A research team led by Genevieve Plant at the University of Michigan took air samples from two sedimentary basins in Texas, the Permian Basin and the Eagle Ford Shale, and around the Bakken Formation — a geological formation rich in oil and gas — straddling the states of North Dakota and Montana. These areas alone concentrate 80% of American natural gas flaring activities.
“We used a small plane equipped with extremely sensitive probes that measure the concentration of methane and carbon dioxide downwind of the flares,” the research director told AFP.
“During this aerial survey, we took approximately 300 separate samples of air from flare stacks in the regions that use the most natural gas flaring in the United States. »
The fossil fuel industry and the US government assume that constantly burning flares destroy methane, the main component of natural gas, with 98% efficiency.
However, the study contradicts this rate and establishes it at 91.1%, or methane emissions in the United States five times higher than the officially published data.
Health impact
Looking further into these numbers, Geneviève Plant’s research team realized that while most flares were operating at 98% efficiency, other flare stacks were showing signs of wear. had an efficiency rate of 60%, not counting the 3 to 5% of extinguished flares which discharge unburned gas into the atmosphere.
Gas flaring is essentially a loss-making activity since the natural gas flared is not associated with any productive process.
The World Bank estimates that with the gas flared each year — 144 billion cubic meters — it would be possible to supply all of sub-Saharan Africa with energy.
According to Mme Plant, there are several ways to lessen the effects of this method. Among them, reducing the volume of flaring activity, increasing the efficiency of flares or even storing and then reusing gas to supply electricity to other equipment.
In an argument attached to the study, two authors, Riley Duren and Deborah Gordon, explain that the activity of gas flaring has harmful consequences on the health of the half-million people who live within a radius of 5 km around the three basins concerned.
“Unlit flares and those with partial combustion can expose frontline populations to a mix of associated pollutants that pose risks of acute and/or chronic health effects,” the authors explained.
Methane is a potent greenhouse gas, with more than 80 times the global warming power of carbon dioxide in the first 20 years after it enters the atmosphere, although carbon dioxide carbon has a more lasting influence.
This is why more than 120 countries have signed a global agreement, the Global Methane Pledge, aiming to reduce emissions by 30% by 2030.