In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 23, No. 11 ( 2023-06-15), p. 6591-6598
Abstract:
Abstract. Solar radiation management through artificially
increasing the amount of stratospheric sulfate aerosol is being considered
as a possible climate engineering method. To overcome the challenge of
transporting the necessary amount of sulfur to the stratosphere, Quaglia and
co-workers suggest deliberate emissions of carbonyl sulfide (OCS), a
long-lived precursor of atmospheric sulfate. In their paper, published in
Atmospheric Chemistry and Physics in 2022, they outline two scenarios with OCS emissions either at the
Earth's surface or in the tropical upper troposphere and calculate the
expected radiative forcing using a climate model. In our opinion, the study
(i) neglects a significantly higher surface uptake that will inevitably be
induced by the elevated atmospheric OCS concentrations and (ii)
overestimates the net cooling effect of this OCS geoengineering approach due
to some questionable parameterizations and assumptions in the radiative
forcing calculations. In this commentary, we use state-of-the-art models to
show that at the mean atmospheric OCS mixing ratios of the two emissions
scenarios, the terrestrial biosphere and the oceans are expected to take up
more OCS than is being released to reach these levels. Using chemistry
climate models with a long-standing record for estimating the climate
forcing of OCS and stratospheric aerosols, we also show that the net
radiative forcing of the emission scenarios suggested by Quaglia and
co-workers is smaller than suggested and insufficient to offset any
significant portion of anthropogenically induced climate change. Our
conclusion is that a geoengineering approach using OCS will not work under
any circumstances and should not be considered further.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-23-6591-2023
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2023
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
