"Addressing these high methane sources and mitigating persistent landfill emissions offers a strong potential for climate benefit," said Dr. Dan Cusworth, lead author of the study and a program scientist with Carbon Mapper, in a press release from Carbon Mapper. "The ability to precisely identify leaks is an efficient way to make quick progress on methane reduction at landfills, which could be critical for slowing global warming."
The study, "Quantifying methane emissions from United States landfills," published in the journal Science, is the largest measurement-based assessment of landfill methane ever conducted. It identifies major sources of emissions that have been absent from traditional accounting so that they can be given precedence for mitigation.
The research team — including scientists from NASA's Jet Propulsion Laboratory, University of Arizona, Arizona State University, the U.S. Environmental Protection Agency (EPA) and airborne atmospheric research company Scientific Aviation — assessed hundreds of the country's landfills using airborne surveys and direct observations.
The study not only emphasized the enormous impact of landfill emissions, but highlighted potential gaps in traditional methods of model-based accounting that could benefit from direct measurements using air-, surface- and space-based monitoring.
