Local and remote climate impacts of future African aerosol emissions

<p>The potential future trend in African aerosol emissions is uncertain, with a large range found in future scenarios used to drive climate projections. The future climate impact of these emissions is therefore uncertain. Using the Shared Socioeconomic Pathway (SSP) scenarios, transient future...

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Main Authors: C. D. Wells, M. Kasoar, N. Bellouin, A. Voulgarakis
Format: Article
Language:English
Published: Copernicus Publications 2023-03-01
Series:Atmospheric Chemistry and Physics
Online Access:https://acp.copernicus.org/articles/23/3575/2023/acp-23-3575-2023.pdf
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author C. D. Wells
C. D. Wells
M. Kasoar
N. Bellouin
A. Voulgarakis
A. Voulgarakis
author_facet C. D. Wells
C. D. Wells
M. Kasoar
N. Bellouin
A. Voulgarakis
A. Voulgarakis
author_sort C. D. Wells
collection DOAJ
description <p>The potential future trend in African aerosol emissions is uncertain, with a large range found in future scenarios used to drive climate projections. The future climate impact of these emissions is therefore uncertain. Using the Shared Socioeconomic Pathway (SSP) scenarios, transient future experiments were performed with the UK Earth System Model (UKESM1) to investigate the effect of African emissions following the high emission SSP370 scenario as the rest of the world follows the more sustainable SSP119, relative to a global SSP119 control. This isolates the effect of Africa following a relatively more polluted future emissions pathway. Compared to SSP119, SSP370 projects higher non-biomass-burning (non-BB) aerosol emissions, but lower biomass burning emissions, over Africa. Increased shortwave (SW) absorption by black carbon aerosol leads to a global warming, but the reduction in the local incident surface radiation close to the emissions is larger, causing a local cooling effect. The local cooling persists even when including the higher African CO<span class="inline-formula"><sub>2</sub></span> emissions under SSP370 than SSP119. The global warming is significantly higher by 0.07 K when including the non-BB aerosol increases and higher still (0.22 K) when including all aerosols and CO<span class="inline-formula"><sub>2</sub></span>. Precipitation also exhibits complex changes. Northward shifts in the Inter-tropical Convergence Zone (ITCZ) occur under relatively warm Northern Hemisphere land, and local rainfall is enhanced due to mid-tropospheric instability from black carbon absorption. These results highlight the importance of future African aerosol emissions for regional and global climate and the spatial complexity of this climate influence.</p>
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spelling doaj.art-e1e3708f485b426199e9e3caa0ea20f12023-03-23T08:55:07ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242023-03-01233575359310.5194/acp-23-3575-2023Local and remote climate impacts of future African aerosol emissionsC. D. Wells0C. D. Wells1M. Kasoar2N. Bellouin3A. Voulgarakis4A. Voulgarakis5The Grantham Institute for Climate Change and the Environment, Imperial College London, London, UKSchool of Earth and Environment, University of Leeds, Leeds, UKLeverhulme Centre for Wildfires, Environment and Society, Department of Physics, Imperial College London, London, UKDepartment of Meteorology, University of Reading, Reading, UKLeverhulme Centre for Wildfires, Environment and Society, Department of Physics, Imperial College London, London, UKSchool of Environmental Engineering, Technical University of Crete, Chania, Greece<p>The potential future trend in African aerosol emissions is uncertain, with a large range found in future scenarios used to drive climate projections. The future climate impact of these emissions is therefore uncertain. Using the Shared Socioeconomic Pathway (SSP) scenarios, transient future experiments were performed with the UK Earth System Model (UKESM1) to investigate the effect of African emissions following the high emission SSP370 scenario as the rest of the world follows the more sustainable SSP119, relative to a global SSP119 control. This isolates the effect of Africa following a relatively more polluted future emissions pathway. Compared to SSP119, SSP370 projects higher non-biomass-burning (non-BB) aerosol emissions, but lower biomass burning emissions, over Africa. Increased shortwave (SW) absorption by black carbon aerosol leads to a global warming, but the reduction in the local incident surface radiation close to the emissions is larger, causing a local cooling effect. The local cooling persists even when including the higher African CO<span class="inline-formula"><sub>2</sub></span> emissions under SSP370 than SSP119. The global warming is significantly higher by 0.07 K when including the non-BB aerosol increases and higher still (0.22 K) when including all aerosols and CO<span class="inline-formula"><sub>2</sub></span>. Precipitation also exhibits complex changes. Northward shifts in the Inter-tropical Convergence Zone (ITCZ) occur under relatively warm Northern Hemisphere land, and local rainfall is enhanced due to mid-tropospheric instability from black carbon absorption. These results highlight the importance of future African aerosol emissions for regional and global climate and the spatial complexity of this climate influence.</p>https://acp.copernicus.org/articles/23/3575/2023/acp-23-3575-2023.pdf
spellingShingle C. D. Wells
C. D. Wells
M. Kasoar
N. Bellouin
A. Voulgarakis
A. Voulgarakis
Local and remote climate impacts of future African aerosol emissions
Atmospheric Chemistry and Physics
title Local and remote climate impacts of future African aerosol emissions
title_full Local and remote climate impacts of future African aerosol emissions
title_fullStr Local and remote climate impacts of future African aerosol emissions
title_full_unstemmed Local and remote climate impacts of future African aerosol emissions
title_short Local and remote climate impacts of future African aerosol emissions
title_sort local and remote climate impacts of future african aerosol emissions
url https://acp.copernicus.org/articles/23/3575/2023/acp-23-3575-2023.pdf
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