Sectoral contributions of high-emitting methane point sources from major U.S. onshore oil and gas producing basins using airborne measurements from MethaneAIR

Abstract. High-emitting methane point sources, quantified by remote sensing methods at individual facilities, have gained significant interest for enabling rapid monitoring and mitigation of methane emissions from the oil and gas sector. Here, we present new methane point source quantifications from MethaneAIR, the airborne precursor to MethaneSAT, from campaigns in 2021–2023 which targeted major oil and gas basins covering ~80 % of U.S. onshore production. Flying at ~12 km above ground, MethaneAIR provides wide-area methane mapping and high-resolution measurements of high-emitting methane point sources. Across 13 major basins, MethaneAIR detected over 400 point sources with emission rates > ~200 kg h^-1, for which we performed detailed attribution to facility categories within oil and gas and non-oil and gas sectors. In 2023, we quantified total point source methane emissions of 360 t h^-1 (95 % confidence interval: 285–445 t h^-1), with ~80 % of the total attributable to oil and gas sources. Non-oil and gas sources made up 50–80 % of observed point source emissions in certain basins, with coal facilities in the Appalachian being the largest source of non-oil and gas methane emissions (24–40 t h^-1). We observe emission source intermittency and significant variation across facility types and basins, highlighting the complex characteristics of high-emitting point sources. Our results emphasize the importance of detailed source attribution for prioritizing mitigation efforts and provide the first analysis of methane point sources in several regions, which will be improved by the observational capabilities of a growing set of methane satellites.