A recent study published in the journal Science examined methane ultra-emitters linked to oil and gas activities and, for the first time, offered a statistical characterization of these major drivers of climate change across various production activities.
The study— Global Assessment of Oil and Gas Methane Ultra-Emitters—was based on data provided by monitoring company Kayrros and shows a direct relationship between ultra-emitters monitored and measured from space and smaller methane leaks detected by local sensors and aircraft surveys.
A team of French and American scientists used high-resolution atmospheric modeling and machine-learning algorithms to detect and quantify methane plumes in Russia, Turkmenistan, the US, Iran, Kazakhstan, and Algeria. The team then aggregated the emissions estimates at a national scale to evaluate the contribution of ultra-emitters to national reported emissions.
“Global oil and gas accounts for at least a quarter of human-made methane emissions, and recent studies provide mounting evidence that its emissions have been widely underestimated by conventional international UNFCCC [UN Framework Convention on Climate Change] protocols in the absence of a global monitoring system able to capture all oil and gas leaks,” said Alexandre d’Aspremont, study contributor and Kayrros cofounder and scientific director. “Our study supplies a first systematic estimate of large methane leaks that can only be seen from space, showing how these detections relate to wider methane monitoring processes.”
The team of scientists performed a systematic analysis of thousands of images produced daily by the European Space Agency satellite mission Sentinel-5P to estimate the amount of methane released into the atmosphere by oil and gas production activities in 2019 and 2020.
“The actual number of ultra-emitters varies by country, but the relationship between the number of sources and their magnitude remains the same,” said lead author Thomas Lauvaux, research scientist at the French Climate and Environmental Science Laboratory. “Intermittent emission events of 25 tons per hour or more can only be detected with monitoring satellites. These huge intermittent events that are normally undetectable consistently account for 8% to 12% of the overall methane emissions from oil and gas activities of any producing country.”
The team detected about 1,800 ultra-emitters—those releasing 25 t/h or more of methane—over the 2 years, of which roughly 1,200 come from oil and gas facilities; the remainder come from a combination of coal mines, agriculture, and waste management. Some of the detected plumes spread over hundreds of kilometers and were being released at a rate of several hundred tons per hour. On average, 50–150 events were detected per month.
Eliminating these oil-and-gas-related events would be tantamount to removing 20 million cars from the road, based on the 100-year global warming power of methane.
In addition to identifying ultra-emitters, the group of scientists used power-law distribution to shed light on the link between intermittent high-resolution imagery from aerial surveys and regular low-resolution images from the satellites.
“The staggering scale of these ultra-emitters and the huge benefit that would result from their elimination far exceed what we anticipated when Kayrros started investing in the development of our Methane Watch platform,” said Antoine Rostand, Kayrros president and cofounder. “However concerning the rate of methane emissions from oil and gas may be today, it is comforting to know that these emissions can, for the most part, easily be eliminated.”
And eliminating the emissions can bring a large economic benefit, said Drew Shindell, one of the paper’s authors. “We find that capturing the methane from these ultra-emitters provides enormous benefits via reduced climate change and improved air quality, so that society as a whole would come out billions of dollars ahead by eliminating these ultra-emitters. As the captured methane is a valuable commodity, the companies or countries capturing the wasted gas also typically come out ahead.”
The study quantified those benefits. Its estimated benefits ranged from $6 billion for Turkmenistan and $4 billion for Russia to $400 million each for Kazakhstan and Algeria.
“Our work on oil and gas is just the beginning,” said Riley Duren, another of the paper’s authors. “The team will now look at methane emissions from coal extraction and farming activities thanks to several recent satellite missions.”
“National greenhouse gas emissions rely primarily on self-reporting, while atmospheric data offers a more rigorous approach to emissions accounting, more independent and more transparent,” Lauvaux added. “In the future, atmospheric measurements will play a more important role in mitigation policies by identifying actionable measures and by monitoring the implementation of climate actions.”