Radiative Forcing and Ozone Depletion of a Decade of Satellite Megaconstellation Missions
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025EF007229
Megaconstellations of thousands of satellites are being rapidly launched into low-Earth orbit, increasing rocket launches and re-entry events. These activities release harmful chemicals throughout the atmosphere, impacting climate and the ozone layer. We use a global inventory of launch and re-entry emissions covering the onset of the megaconstellation era (2020–2022), and project these to 2029 based on 2020–2022 growth rates. We implement this inventory into a 3D atmospheric chemistry model to determine the impacts of megaconstellations on the ozone layer and climate. We find that global stratospheric ozone depletion from all mission types is relatively small compared to surface sources and megaconstellation missions only account for about one-tenth of this depletion. This is because rockets launching megaconstellations almost all use kerosene, a large source of black carbon or soot particles, but not of chemicals such as chlorine that directly destroy ozone. Soot from rockets absorbs sunlight, warming the upper layers of the atmosphere and decreasing the amount of sunlight reaching Earth's lower atmosphere, causing it to cool. Megaconstellation missions are responsible for about half of this climate effect. In this regard, rockets launching megaconstellations and other missions are like small-scale stratospheric aerosol injection experiments without forethought for potential unintended consequences.