We study 96 cities that are members of C40, a network of mayors of global cities dedicated to delivering action on climate change (C40, 2021). For each city, we consider anthropogenic, biogenic, mineral dust, soil denitrification, and biomass burning emissions. For anthropogenic emissions, we use data from the Community Emissions Data System (CEDS) for year 2014 with eight sectors (Table ): non-combustion agriculture (AGR); energy transformation and extraction (ENE); industrial combustion and processes (IND); surface transportation (road, rail, other) (TRA); residential, commercial, and other (RCO); solvents (SLV); waste disposal and handling (WST); and international shipping (SHP) . The CEDS emission species used here and their mappings to InMAP species are summarized in Table . The CEDS emissions dataset is available at 0.5×0.5 degree spatial resolution, meaning that a single emissions grid cell is larger than many of the cities we study. Section 2.2 describes our methods for downscaling these emissions data to produce higher-resolution estimates.