No Emergency Brake: Slow Ocean Response to Abrupt Stratospheric Aerosol Injection

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Sep 14, 2023, 12:22:54 PM9/14/23

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https://essopenarchive.org/doi/full/10.22541/essoar.169447423.32818318/v1

Authors

Daniel Pflüger
Claudia Elisabeth Wieners
Leo van Kampenhout
René Wijngaard,
Henk A. Dijkstra

Peer review timeline

01 Sep 2023Submitted to ESS Open Archive

11 Sep 2023Published in ESS Open Archive

Cite as: Daniel Pflüger, Claudia Elisabeth Wieners, Leo van Kampenhout, et al. No Emergency Brake: Slow Ocean Response to Abrupt Stratospheric Aerosol Injection. ESS Open Archive . September 11, 2023.
DOI: 10.22541/essoar.169447423.32818318/v1

Abstract

Given the possibility of irreversible changes to the Earth system, technological interventions such as solar radiation management (SRM) are sometimes framed as possible climate emergency brakes. However, little knowledge exists on the efficacy of such disruptive interventions. To fill in this gap, we perform Community Earth System Model 2 (CESM 2) simulations of a SSP5-8.5 scenario on which we impose either gradual early-century SRM to stabilise surface temperatures or a rapid late-century cooling, both realised via stratospheric aerosol injection (SAI). While both scenarios cool Earth’s surface, we find that ocean conditions differ drastically. The rapid-cooling scenario fails to dissipate sub-surface ocean heat content (OHC), ends up in a weaker AMOC state and does not restore an ailing North Atlantic deep convection. Furthermore, the weakened AMOC state mediates the climate response to rapid SAI, thus inducing an interhemispheric temperature asymmetry. Our results advise caution when considering SAI as an emergency intervention.