Methane is a greenhouse gas, and the second most important contributor to human-caused climate change. It is also an important target for climate mitigation policy in the state of California. However, the methane budget is poorly known, especially at scales that are most relevant for mitigation policy and planning. New observations of methane emissions, such as airborne imaging of methane point sources, have potential to fill some of these gaps. To complement this approach, we developed Vista-California, an inventory >400,000 potentially methane emitting facilities across the state. Vista enables interpretation of these atmospheric measurements by providing scale-appropriate source information, and additionally contributes to research planning, spatial attribution, and scaling analyses. Among the different sectors that produce methane, we give special attention to dairy farms, the largest producer of methane emissions in California, and to oil and gas, which has received increased attention in the U.S. over the past decade. Datasets such as these will be important for future satellite missions that seek to identify methane point sources from space.

Prof. Francesca Hopkins