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Berkeley Lab researcher Sebastien Biraud (Courtesy Sebastien Biraud) |
Sébastien Biraud is a Berkeley Lab scientist leading an effort to identify and mitigate some of the largest emitters of methane in California’s Southern San Joaquin Valley. Methane is a short-lived air pollutant and greenhouse gas capable of warming the atmosphere about 80 times as fast as the far longer-lived carbon dioxide over 20 years. This month the U.S. and European Union launched the Global Methane Pledge at the United Nations Climate Change conference, in recognition of the chance countries have to slow climate change by tackling methane emissions–possibly even before the end of this decade. Countries joining the pledge commit to a collective goal of reducing global methane emissions by at least 30% from 2020 levels before 2030 with a particular focus on sources of high emissions.
Since 2019 Biraud and team have been setting up a framework for pinpointing and monitoring these “super emitters” in California’s Southern San Joaquin Valley where more than 50% of methane emissions can be traced back to less than 10% of super emitters from the dairy and oil and gas industries. Their goal is to identify the super emitters at the scale of individual oil wells, fields, or entire regions, quantify the amount of methane emitted, then use that information to help inform mitigation approaches across California and elsewhere.
Q. Why monitor methane? Why is it important to identify methane super-emitters?
Methane is emitted during energy production, raising livestock, and the decay of organic waste in landfills. Methane is what we call a “short-lived” climate forcer because it stays in the atmosphere for far less time than other greenhouse gasses such as carbon dioxide – 10 years versus more than 100 years for CO2. The molecular structure of methane is such that it is capable of warming the atmosphere about 80 times as fast as carbon dioxide. That’s bad news for warming as there’s evidence that methane could cause more warming over the next 10 years than CO2.
Although this is clearly a challenge, this also presents a great opportunity to act: by reducing methane emissions, we can reduce methane induced-warming and slow down the rate of warming. If we do this right, there’s potential to see results from cuts to methane emissions in as little as 10 years.
And that’s where super-emitters come in. Multiple atmospheric studies have identified that methane emissions have been significantly underestimated by greenhouse gas inventories for the U.S., California, and select cities. Other studies have provided compelling evidence indicating that in California a relatively small number of super-emitters – in some cases 1 to 10% of potential sources – contribute more than half of the methane emissions. We can’t make the reductions needed without addressing these super emitters.