Air quality model description: The Intervention Model for Air Pollution (InMAP) is a mechanistic reduced-complexity air quality model (RCM) that estimates annual-average changes in primary and secondary PM2.5 concentrations attributable to annual changes in emissions of PM2.5 and its precursors. In addition to the emissions and population data described in Section 2.1, InMAP requires information on meteorological characteristics and on chemical transport and reaction rates. We use meteorological and background chemistry inputs generated from the outputs of the GEOS-Chem global atmospheric chemical transport model (CTM) simulation for the year 2016, with a base spatial resolution of 2×2.5 degrees and regional nests over Asia, Europe, and North America at 0.5×0.625 degree spatial resolution. The GEOS-Chem simulation uses the SOA_SVPOA chemical mechanism with standard emissions inputs as processed by the HEMCO emissions processor. Further details regarding the GEOS-Chem configuration are described by .