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...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-03-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/3575/2023/acp-23-3575-2023.pdf |
| Summary: | <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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| ISSN: | 1680-7316 1680-7324 |