Harmonized global to regional gridded methane inventories in a discrete global grid framework

Mingke Li , Mozhou Gao, Steve H.L. Liang

Existing gridded methane emission inventories vary widely in resolution, sector schemes, formats, and units, hindering cross-comparison, integration with measurements, and use in emerging analytical frameworks, particularly because latitude-longitude grids have non-uniform cell areas that bias comparison and aggregation. Here, we present a harmonized methane emissions dataset that standardizes 13 heterogeneous gridded inventories across global, continental, national, and regional scales. National datasets include the United States, Canada, Mexico, India, Australia, China, and Switzerland, with emphasis on energy-related emissions from coal mining and oil and gas activities. All inventories were converted into the rearranged Hierarchical Equal Area isoLatitude Pixelization (rHEALPix) Discrete Global Grid System (DGGS) at resolution levels aligned with native spatial scales. Spatial structure, sector classification, and reporting units were standardized, and quantitative validation confirmed high consistency before and after conversion. The resulting dataset offers an equal-area, hierarchical, machine-readable framework enabling consistent comparison and aggregation across sectors, countries, years, and resolutions. The harmonized structure supports applications from atmospheric inversions and hotspot detection to benchmarking, mitigation planning, and AI-ready spatial analysis and model integration.