Satellites have discovered close to 800 methane leaks from just four countries since November 2017. Using a new approach to identify sources of the powerful greenhouse gas, the researchers behind the work found that more than two thirds of the leaks they identified are recurring, suggesting that they could be fixed through improved maintenance of leaky fossil fuel infrastructure.
, but Leaks usually arise from fossil fuel infrastructure such as oil rigs, gas wells and pipelines, and stemming them could buy us more time in our efforts to tackle climate change. Last week at the COP26 summit, 105 countries pledged to cut methane emissions by 30 per cent by 2030. Figuring out better ways to monitor global methane levels will be key to achieving this goal.
To identify some of the sources of leaked methane,聽 and his colleagues used and the satellites to look for major methane leaks across seven countries between November 2017 and June 2021. Of the 793 leaks they detected using infrared, 786 came from Algeria, Turkmenistan, the US and Uzbekistan.
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The problem with methane detection is that it is difficult to have both good temporal and spatial resolution, says , who wasn鈥檛 involved in the study. 鈥淚n other words, aircraft can see much smaller plumes than satellites, but they can鈥檛 observe the whole world every few days.鈥�
Satellites can see far more of the world than aircraft and for far longer, but it is more difficult to pinpoint where leaks are coming from and to discover smaller leaks. 鈥淭his is the first study to use this capability [of the two satellites] to scan for plumes across wide areas of the world,鈥� says Varon.
The researchers found that 68 per cent of the leaks they recorded were recurring, meaning they could be avoided with better maintenance of the facilities. They also found that Algeria had the highest number of methane leaks with 376, while the US, which had the third-highest number, only had 58.
Varon says this points to the shortcomings in the technology. 鈥淚n my work, I鈥檝e found that Sentinel-2 gives much more reliable methane data when viewing bright and uniform scenes 鈥� like in the desert 鈥� which makes it easier to identify plumes in places like Algeria than in the US,鈥� he says.
鈥淓veryone鈥檚 excited about satellites because you don鈥檛 need permission from Russia or China to estimate their methane emissions,鈥� says . But the technology still has a lot of limitations, he says, such as its inability to find smaller leaks and its dependence on clear skies.
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