U.S. Oil and Natural Gas Production Emit More Methane Than Previously Thoughthttps://phys.org/news/2021-03-oil-natural-gas-production-emit.htmlThe Environmental Protection Agency (EPA) is underestimating methane emissions from oil and gas production in its annual Inventory of U.S. Greenhouse Gas Emissions and Sinks, according to new research from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). The research team found 90 percent higher emissions from oil production and 50 percent higher emissions for natural gas production than EPA estimated in its latest inventory.
The paper is published in the journal
Atmospheric Chemistry and Physics.The research team, led by Joannes Maasakkers, a former graduate student at SEAS, developed a method to trace and map total emissions from satellite data to their source on the ground.
Currently, the EPA only reports total national emissions to the UNFCC. SEAS researchers worked with the EPA to map regional emissions of methane from different sources in the US. That level of detail was used to simulate how methane moves through the atmosphere.
In this paper, the researchers compared those simulations to satellite observations from 2010-2015. Using a transport model, they were able to trace the path of emissions from the atmosphere back to the ground and identify areas across the US where the observations and simulations didn't match up.
The biggest discrepancy was in emissions from oil and natural gas production.
The EPA calculates emission based on processes and equipment. For example, the EPA estimates that a gas pump emits a certain amount of methane, multiplies that by how many pumps are operating across the country, and estimates total emissions from gas pumps.
... "We know that a relatively small number of facilities make up most of the emissions and so there are clearly facilities that are producing more emissions than we would expect from these overall estimates."
Joannes D. Maasakkers et al.
2010–2015 North American methane emissions, sectoral contributions, and trends: a high-resolution inversion of GOSAT observations of atmospheric methane,
Atmospheric Chemistry and Physics (2021)
https://acp.copernicus.org/articles/21/4339/2021/