Radiative Forcing and Ozone Depletion of a Decade of Satellite Megaconstellation Missions

Le résumé fourni par la source

Abstract Satellite megaconstellations (SMCs) are driving rapid increases in rocket launch and re‐entry rates, emitting pollutants throughout the atmosphere. The environmental impact of SMCs lacks characterization to determine the need for regulation. We utilize a global 3D emission inventory of recent (2020–2022) space activity that distinguishes SMC and non‐SMC emissions. We calculate a decade of emissions using trends in propellant consumption and re‐entry mass to project growth rates in SMC (28% a −1 ) and non‐SMC (<20% a −1 ) propellant and re‐entry mass. We implement this in the GEOS‐Chem chemical transport model coupled to a radiative transfer model to characterize impacts of SMCs and all mission types on atmospheric composition and climate. By 2029, global chemical loss of stratospheric ozone from all missions, dominated by chlorine from solid propellant, is small (0.02%) compared to regulated sources (2%). SMC missions predominantly use kerosene‐fueled rockets that do not emit chlorine, so account for only 9% of all‐mission ozone depletion. Kerosene is a large source of black carbon (BC) that induces positive instantaneous radiative forcing per mass unit BC emitted that is more than 500 times greater than BC forcing from Earth‐bound sources. Unlike surface sources, BC from rockets are released above the tropopause, so behave like potential solar geoengineering strategies: positive instantaneous forcing (6.47 mW m −2 ), negative stratospherically adjusted forcing (−6.40 mW m −2 ). SMCs account for over half (56%) the instantaneous forcing and 42% of the stratospherically adjusted forcing. Ambient measurements and laboratory studies are critically needed to constrain and validate our model findings.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.