Understanding and mitigating methane emissions: examples from California agencies and operators

Abstract:

High resolution remote sensing of methane sources, when combined with transparent data sharing and sustained collaboration with facility operators and relevant agencies has the potential to enable mitigation and improved collective understanding of emissions. This is a key objective of the CMS Prototype Methane Monitoring System for California and Multi-tiered Carbon Monitoring System projects. These projects leveraged the 2016-2018 California Methane Survey that identified and quantified methane point source emissions from hundreds of sources that spanned the energy, waste management, and agriculture sectors. The AVIRIS-NG airborne imaging spectrometer allows for high resolution mapping of methane plumes rapidly over large areas. We exploited this capacity to pinpoint source locations, estimate emission rates, and attribute sources to facilities and emission sectors. We shared these findings with representative state and local agencies, private sector companies, and the public through direct research collaborations and Methane Source Finder, a web-based data portal developed under NASA’s CMS and ACCESS programs. The sustained and iterative dialogue with operators in particular was key for accurate source attribution and process understanding that would not have been possible with remote sensing alone. In this presentation, we show how these data sets are contributing to co-production of knowledge by scientists, operators and agencies – resulting in improved understanding of methane emissions at individual facilities and California’s overall methane budget. We will highlight examples where sharing results with operators led to mitigation of emissions from the energy and landfill sectors. We will also discuss expansion of this framework (including tiered observations from satellites, aircraft and surface measurements) beyond California and the potential for future spaceborne monitoring of facility-scale emissions and transparent data sharing for advancing understanding of regional and global methane budgets and emission mitigation.

Figure caption: Methane Source Finder illustrating results from a tiered observing system for the Los Angeles Basin including the locations of methane plume images (blue circles), point source emission estimates, gridded methane flux maps, and facility/infrastructure data layers. Examples of plumes that were shared with operators and resulted in emission mitigation include at a gas storage facility (A), gas distribution pipeline leak (B), LNG tank leak (C) and landfill (D).