Flawed Emergency Intervention: Slow Ocean Response to Abrupt Stratospheric Aerosol Injection

• Published in: Geophysical Research Letters
• Main Authors: Daniel Pflüger, Claudia E. Wieners, Leo vanKampenhout, René R. Wijngaard, Henk A. Dijkstra
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2024
• Subjects: stratospheric aerosol injection; Atlantic meridional overturning circulation; ocean heat content; subpolar gyre; deep convection; tipping points; Geophysics. Cosmic physics; QC801-809; North Atlantic
• Online Access: https://doi.org/10.1029/2023GL106132; https://doaj.org/article/eaa3b0b7824449b897b8beea5e2ff20b

Abstract Given the possibility of irreversible, anthropogenic changes in the climate system, technologies such as solar radiation management (SRM) are sometimes framed as possible emergency interventions. However, little knowledge exists on the efficacy of such deployments. To fill in this gap, we perform Community Earth System Model 2 simulations of an intense warming scenario on which we impose gradual early‐century SRM or rapid late‐century cooling (an emergency intervention), both realized via stratospheric aerosol injection (SAI). While both scenarios cool Earth's surface, ocean responses differ drastically. Rapid cooling fails to release deep ocean heat content or restore an ailing North Atlantic deep convection but partially stabilizes the Atlantic meridional overturning circulation. In contrast, the early intervention effectively mitigates changes in all of these features. Our results suggest that slow ocean timescales impair the efficacy of some SAI emergency interventions.