Global 3D rocket launch and re-entry air pollutant and CO2 emissions at the onset of the megaconstellation era

Satellite megaconstellation (SMC) missions are spurring rapid growth in rocket launches and anthropogenic re-entries. These events inject pollutants and carbon dioxide (CO 2 ) in all atmospheric layers, affecting climate and stratospheric ozone. Quantification of these and other environmental impacts requires reliable inventories of emissions. We present a global, hourly, 3D, multi-year inventory of air pollutant emissions and CO 2 from rocket launches and object re-entries spanning the inception and growth of SMCs (2020–2022). We use multiple reliable sources to compile information needed to build the inventory and conduct rigorous and innovative cross-checks and validations against launch livestreams and past studies. Our inventory accounts for rocket plume afterburning effects, applies object-specific ablation profiles to re-entering objects, and quantifies unablated mass of objects returning to Earth. We also identify all launches and objects associated with SMC missions, accounting for 37–41% of emissions of black carbon particles, carbon monoxide, and CO 2 by 2022. The data are provided in formats for ease-of-use in atmospheric chemistry and climate models to inform regulation and space sustainability policies.