Identifying Climate Impacts From Different Stratospheric Aerosol Injection Strategies in UKESM1

Abstract Stratospheric Aerosol Injection (SAI) is a proposed method of climate intervention aiming to reduce the impacts of human‐induced global warming by reflecting a portion of incoming solar radiation. Many studies have demonstrated that SAI would successfully reduce global‐mean surface air temp...

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Main Authors: Alice F. Wells, Matthew Henry, Ewa M. Bednarz, Douglas G. MacMartin, Andy Jones, Mohit Dalvi, James M. Haywood
Format: Article
Language:English
Published: Wiley 2024-03-01
Series:Earth's Future
Subjects:
Online Access:https://doi.org/10.1029/2023EF004358
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author Alice F. Wells
Matthew Henry
Ewa M. Bednarz
Douglas G. MacMartin
Andy Jones
Mohit Dalvi
James M. Haywood
author_facet Alice F. Wells
Matthew Henry
Ewa M. Bednarz
Douglas G. MacMartin
Andy Jones
Mohit Dalvi
James M. Haywood
author_sort Alice F. Wells
collection DOAJ
description Abstract Stratospheric Aerosol Injection (SAI) is a proposed method of climate intervention aiming to reduce the impacts of human‐induced global warming by reflecting a portion of incoming solar radiation. Many studies have demonstrated that SAI would successfully reduce global‐mean surface air temperatures; however the vast array of model scenarios and strategies result in a diverse range of climate impacts. Here we compare two SAI strategies—a quasi‐ equatorial injection and a multi‐latitude off‐equatorial injection—simulated with the UK Earth System Model (UKESM1), both aiming to reduce the global‐mean surface temperature from that of a high‐end emissions scenario to that of a moderate emissions scenario. We compare changes in the surface and stratospheric climate under each strategy to determine how the climate response depends on the injection location. In agreement with previous studies, an equatorial injection results in a tropospheric overcooling in the tropics and a residual warming in the polar regions, with substantial changes to stratospheric temperatures, water vapor and circulation. Previous comparisons of equatorial versus off‐equatorial injection strategies are limited to two studies using different versions of the Community Earth System Model. Our study evaluates how the climate responds in UKESM1 under these injection strategies. Our results are broadly consistent with previous findings, concluding that an off‐equatorial injection strategy can minimize regional surface temperature and precipitation changes relative to the target. We also present more in‐depth analysis of the associated changes in Hadley Circulation and regional temperature changes, and call for a new series of inter‐model SAI comparisons using an off‐equatorial strategy.
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spelling doaj.art-b4bb4593d8474ae691a93193720319712024-04-06T12:00:35ZengWileyEarth's Future2328-42772024-03-01123n/an/a10.1029/2023EF004358Identifying Climate Impacts From Different Stratospheric Aerosol Injection Strategies in UKESM1Alice F. Wells0Matthew Henry1Ewa M. Bednarz2Douglas G. MacMartin3Andy Jones4Mohit Dalvi5James M. Haywood6Faculty of Environment, Science and Economy Department of Mathematics and Statistics University of Exeter Exeter UKFaculty of Environment, Science and Economy Department of Mathematics and Statistics University of Exeter Exeter UKCooperative Institute for Research in Environmental Sciences (CIRES) University of Colorado Boulder Boulder CO USASibley School of Mechanical and Aerospace Engineering Cornell University Ithaca NY USAMet Office Exeter UKMet Office Exeter UKFaculty of Environment, Science and Economy Department of Mathematics and Statistics University of Exeter Exeter UKAbstract Stratospheric Aerosol Injection (SAI) is a proposed method of climate intervention aiming to reduce the impacts of human‐induced global warming by reflecting a portion of incoming solar radiation. Many studies have demonstrated that SAI would successfully reduce global‐mean surface air temperatures; however the vast array of model scenarios and strategies result in a diverse range of climate impacts. Here we compare two SAI strategies—a quasi‐ equatorial injection and a multi‐latitude off‐equatorial injection—simulated with the UK Earth System Model (UKESM1), both aiming to reduce the global‐mean surface temperature from that of a high‐end emissions scenario to that of a moderate emissions scenario. We compare changes in the surface and stratospheric climate under each strategy to determine how the climate response depends on the injection location. In agreement with previous studies, an equatorial injection results in a tropospheric overcooling in the tropics and a residual warming in the polar regions, with substantial changes to stratospheric temperatures, water vapor and circulation. Previous comparisons of equatorial versus off‐equatorial injection strategies are limited to two studies using different versions of the Community Earth System Model. Our study evaluates how the climate responds in UKESM1 under these injection strategies. Our results are broadly consistent with previous findings, concluding that an off‐equatorial injection strategy can minimize regional surface temperature and precipitation changes relative to the target. We also present more in‐depth analysis of the associated changes in Hadley Circulation and regional temperature changes, and call for a new series of inter‐model SAI comparisons using an off‐equatorial strategy.https://doi.org/10.1029/2023EF004358climate interventionstratospheric aerosol injectionclimate changeclimate impactsgeoengineeringclimate
spellingShingle Alice F. Wells
Matthew Henry
Ewa M. Bednarz
Douglas G. MacMartin
Andy Jones
Mohit Dalvi
James M. Haywood
Identifying Climate Impacts From Different Stratospheric Aerosol Injection Strategies in UKESM1
Earth's Future
climate intervention
stratospheric aerosol injection
climate change
climate impacts
geoengineering
climate
title Identifying Climate Impacts From Different Stratospheric Aerosol Injection Strategies in UKESM1
title_full Identifying Climate Impacts From Different Stratospheric Aerosol Injection Strategies in UKESM1
title_fullStr Identifying Climate Impacts From Different Stratospheric Aerosol Injection Strategies in UKESM1
title_full_unstemmed Identifying Climate Impacts From Different Stratospheric Aerosol Injection Strategies in UKESM1
title_short Identifying Climate Impacts From Different Stratospheric Aerosol Injection Strategies in UKESM1
title_sort identifying climate impacts from different stratospheric aerosol injection strategies in ukesm1
topic climate intervention
stratospheric aerosol injection
climate change
climate impacts
geoengineering
climate
url https://doi.org/10.1029/2023EF004358
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