https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2025JD043576

*Authors: *Atanas Dommo, Francis Nkrumah, Kwesi A. Quagraine, Nana Ama
Browne Klutse, Gandome Mayeul Léger Davy Quenum, Hubert A. Koffi

First published: *17 October 2025*

https://doi.org/10.1029/2025JD043576

*Abstract*
This study investigates the response of surface cloud radiative effects
(CREs) to Assessing Responses and Impacts of Solar Climate Intervention on
the Earth system with Stratospheric Aerosol Injection (ARISE-SAI) relative
to Shared Socio-Economic Pathways (SSP2-4.5) across three regions: Southern
West Africa (SWA), Central Africa (CA), and Sahara (SAH). We utilize 10
members of the simulations from the Community Earth System Model version 2
(CESM2) with the Whole Atmosphere Community Climate Model version 6
(WACCM6) under the ARISE-SAI-1.5 scenario, comparing the outputs to those
from the SSP2.4-5 scenario. Compared to SSP2-4.5, the findings indicate
that ARISE-SAI-1.5 has the potential to mitigate the decreasing trend of
shortwave cloud cooling by −0.35, −0.99, and −0.20 W/m2, while
significantly enhancing the longwave warming by +1.06, +0.62, and +0.23
W/m2, over CA, SWA, and SAH, respectively, during the period 2035–2069.
However, the changes in shortwave cloud cooling are not robust and may be
attributable to natural variability rather than the direct effects of
ARISE-SAI. The changes in cloud radiative effects underpin high sensitivity
to changes in liquid water path, while the increased fractional cloud cover
contributes to enhancing longwave cloud warming at the surface. Results
also reveal strengthened precipitation associated with increased shortwave
cloud cooling effect outweighing its longwave counterpart on the one hand
or increased shortwave cloud cooling and reduced longwave cloud warming on
the other hand. It is noteworthy that our results, although based solely on
ARISE-SAI-1.5 simulations, pave the way to comprehensive comparisons
between model results for a better assessment of the impacts of SAI
deployment.

*Plain Language Summary*
Stratospheric Aerosol Injection is a technique for introducing sulfur
dioxide into the atmosphere to form sulfate aerosols that would cool the
Earth's surface, thereby mitigating the adverse effects of anthropogenic
global warming. Simulations termed Assessing Responses and Impacts of Solar
Climate Intervention on the Earth system with Stratospheric Aerosol
Injection are utilized in this study to examine to what extent cloud may
cool or warm the surface in order to evaluate the impact of the
aforementioned technique over Central Africa, Southern West Africa, and the
Sahara. Investigating the response of cloud radiative effects to
Stratospheric Aerosol Injection is of paramount importance in assessing the
broad impacts of that technique. The findings indicate that Stratospheric
Aerosol Injection could mitigate the decreasing trend of longwave cloud
radiative effects induced by global warming over Central Africa, Southern
West Africa, and the Sahara region compared to moderate scenarios. One of
the possible implications of this technology after deployment could be the
strengthened precipitation as a response to increased shortwave cloud
cooling driven by enhanced liquid water in the atmospheric column over
southern West Africa, the Sahara, and Central Africa.

*Key Points*

Stratospheric Aerosol Injection could mitigate the decreasing trend of
longwave cloud warming under rising greenhouse gases

Strengthened precipitation could be associated with increased shortwave
cloud cooling outweighing longwave cloud warming effect changes

The changes in cloud radiative effects are highly sensitive with changes in
liquid water path

*Source: AGU*

-- 
You received this message because you are subscribed to the Google Groups 
"geoengineering" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion visit 
https://groups.google.com/d/msgid/geoengineering/CAHJsh99tsgEAF0-ZCTuBfVgQ-09YpU_R2gCY7y9PS97W97xgpQ%40mail.gmail.com.

Reply via email to