Aerosol emissions occur in tandem with greenhouse gases (GHGs) and vary by type of economic activity, so concurrent changes to aerosols from GHG reduction depend on what activities are reduced. We show that, by 2030, the different policy priorities can differ by more than a million premature deaths annually and could cause a similar amount of cooling as from the reduced GHGs, indicating that there are substantial tradeoffs between global climate and local air quality objectives. We conclude that deliberate consideration of particle emissions as part of climate policy could provide additional benefits, especially in less industrialized regions.