A comprehensive analysis of 383 U.S. cities reveals a striking pattern: most have rings of isolation in suburban areas and segregated pockets of near the urban core, that are shaped by race, wealth, and proximity to downtown, finds a new study by UCL researchers.

High-resolution data from the GHGSat satellite constellation reveal facility-level methane emissions at thousands of individual sites worldwide, according to a new study. The findings provide a far more detailed picture of methane emissions from the energy sector, offering new insights for global inventories and mitigation strategies. Methane is among the most powerful drivers of atmospheric warming a after carbon dioxide, and much of it comes from human activities – often from concentrated “point sources” such as individual oil, gas, and coal facilities. Methane emissions from these industries are generally estimated in two ways: bottom-up inventories and top-down atmospheric measurements. Bottom-up methods, based on limited ground measurements or assumptions about industrial activity, can miss unexpected or short-lived leaks. On the other hand, top-down approaches provide more direct data, but typically lack the resolution or frequency needed to identify individual emission sources. Together, these limitations highlight the need for improved tools that capture both detailed and comprehensive emissions information.

According to Dylan Jervis and colleagues, the GHGsat satellite network offers an ideal combination of high spatial resolution, strong sensitivity, and broad global coverage to better understand where methane is released and how those emissions change over time. Using global GHGSat observations from 2023, Jervis et al. grouped repeated methane plume detections from the same locations into time series and calculated how frequently each site emits above the satellites’ detection limit. They then used these patterns to estimate yearly average emissions for 3,114 oil, gas, and coal facilities worldwide, which totaled roughly 8.3 million tons per year of methane released. They found that oil and gas emissions fluctuate much more than coal emissions, meaning they require many more satellite observations to detect and quantify, which the authors argue is an important consideration for future monitoring rules. When these high-resolution estimates were compared with other major global inventories and lower-resolution satellite datasets, coal emissions matched well at the country level, while oil and gas emissions showed only moderate agreement and weak correlation at finer scales. The authors note that these differences highlight the importance of high-resolution satellites for identifying large, variable emitters that broader inventories overlook or misrepresent.