Impact of Rocket Launch and Space Debris Air Pollutant Emissions on
Stratospheric Ozone and Global Climate
Abstract
Detailed examination of the impact of modern space launches on the
Earth’s atmosphere is crucial, given booming investment in the space
industry and an anticipated space tourism era. We develop air pollutant
emissions inventories for rocket launches and re-entry of reusable
components and debris in 2019 and for a speculative space tourism
scenario based on the recent billionaire space race. This we include in
the global GEOS-Chem model coupled to a radiative transfer model to
determine the influence on stratospheric ozone (O3) and
climate. Due to recent surge in re-entering debris and reusable
components, nitrogen oxides from ablation and chlorine from solid fuels
contribute equally to all stratospheric O3 depletion by
contemporary rockets. Decline in global stratospheric O3
is small (0.01%), but reaches 0.15% in the upper stratosphere
(~5 hPa, 40 km) in spring at 60-90°N after a decade of
sustained 5.6% a-1 growth in 2019 launches and
re-entries. This increases to 0.22% with a decade of emissions from
space tourism rockets, undermining O3 recovery achieved
with the Montreal Protocol. Rocket emissions of black carbon (BC)
produce substantial global mean warming of 8 mW m-2
after just 3 years of routine space tourism launches. This is a much
greater contribution to global radiative forcing (6%) than emissions
(0.02%) of all other BC sources, as warming per unit mass emitted is
~500 times more than surface and aviation sources. The
O3 damage and warming we estimate should motivate
regulation of an industry poised for rapid growth.