Assessing the Impact of Stratospheric Aerosol Injection on US Convective Weather Environments

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https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2023EF004041

Authors 

Ivy Glade, James W. Hurrell, Lantao Sun, Kristen L. Rasmussen

First published: 26 December 2023

https://doi.org/10.1029/2023EF004041

Abstract

Continued climate warming, together with the overall evaluation and implementation of a range of climate mitigation and adaptation approaches, has prompted increasing research into proposed solar climate intervention methods, such as stratospheric aerosol injection (SAI). SAI would use aerosols to reflect a small amount of incoming solar radiation away from Earth to stabilize or reduce future warming due to increasing greenhouse gas concentrations. Research into the possible risks and benefits of SAI relative to the risks from climate change is emerging. There is not yet, however, an adequate understanding of how SAI might impact human and natural systems. For instance, little to no research to date has examined how SAI might impact environmental conditions critical to the formation of severe convective weather over the United States (US). This study uses ensembles of Earth system model simulations of future climate change, with and without hypothetical SAI deployment, to examine possible future changes in thermodynamic and kinematic parameters critical to the formation of severe weather during convectively active seasons over the US Results show that simulated forced changes in thermodynamic parameters are significantly reduced under SAI relative to a climate change (SSP2-4.5) world, while simulated changes in kinematic parameters are more difficult to distinguish. Also, unforced internal climate variability is likely to significantly modulate the projected forced climate changes over large regions of the US.

Key Points

Thermodynamic parameters relevant to severe weather formation are projected to increase in magnitude over the US due to climate change

Stratospheric aerosol injection may prevent many of these projected increases

Internal decadal-scale climate variability is likely to impact future projections of regional changes in convective weather environments

Plain Language Summary

Human-caused climate warming is projected to increase occurrences of environmental conditions which favor the formation of severe weather, such as thunderstorms. Stratospheric aerosol injection (SAI) is a form of climate intervention which aims to cool the planet by injecting sunlight-reflecting particles into the stratosphere, a part of the upper atmosphere. This study investigates how SAI might impact future projections of the environmental conditions which favor the formation of severe weather. One set of climate models simulations show that future increases of the occurrence of temperature driven environmental characteristics that favor the formation of severe weather could be avoided if SAI were to be implemented. These simulations also show that future projections of environmental characteristics that favor the formation of severe weather that are dynamically driven may not be significantly impacted by the implementation of SAI. Climate variability that is not human-driven may also significantly impact future projections of the environmental conditions which favor severe weather formation, whether or not SAI has been implemented.

Source: AGU