Simulated response of the climate of eastern Africa to stratospheric aerosol intervention
Eastern Africa is vulnerable to extreme climate events, including droughts and floods, which are expected to become more frequent and intense in the future. This paper evaluates the potential of solar radiation management (SRM) with stratospheric aerosol injection (SAI) to influence the projected cl...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2025-04-01
|
| Series: | Frontiers in Climate |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fclim.2025.1522235/full |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850152406978920448 |
|---|---|
| author | Herbert O. Misiani Hussen S. Endris Franklin J. Opijah Jully O. Ouma Betty N. Barasa Mari R. Tye Mari R. Tye Douglas G. MacMartin |
| author_facet | Herbert O. Misiani Hussen S. Endris Franklin J. Opijah Jully O. Ouma Betty N. Barasa Mari R. Tye Mari R. Tye Douglas G. MacMartin |
| author_sort | Herbert O. Misiani |
| collection | DOAJ |
| description | Eastern Africa is vulnerable to extreme climate events, including droughts and floods, which are expected to become more frequent and intense in the future. This paper evaluates the potential of solar radiation management (SRM) with stratospheric aerosol injection (SAI) to influence the projected climate, including extreme events, over the region. The study utilized climate simulation outputs from the Community Earth System Model version 2 with the Whole Atmosphere Community Climate Model (CESM2-WACCM6) to assess future climate changes under two scenarios: one without Solar Aerosol Injection (SAI) following the SSP2-4.5 emissions pathway, and another with SAI, based on the first set of simulations from the Assessing Responses and Impacts of Solar Climate Intervention on the Earth System with Stratospheric Aerosol Injection (ARISE-SAI) project. The analysis of model performance was conducted for the 1981–2010 period, while future changes were assessed over two climatological periods: the near-term (2035–2054) and the mid-term (2050–2069). Changes in extreme temperatures and rainfall events were evaluated using four extreme indices: two for temperature (WSDI and DTR) and two for rainfall (CDD and CWD). Additionally, the Standardized Precipitation-Evapotranspiration Index (SPEI) was used to assess changes in the frequency of extreme wet and dry events. In the historical period, there is good agreement between the observed and simulated data in representing the spatial distribution of temperature and rainfall over the region, despite the slight overestimation and underestimation by the model in some areas. The model effectively captures the seasonal cycles of rainfall and temperature over the cities of interest. Analysis of future projections indicates that temperatures are projected to rise consistently in the future under the SSP2-4.5 scenario. However, SAI produces a steady trend in the four cities, suggesting SAI’s potential to counteract warming in Eastern Africa. Rainfall is projected to increase in the equatorial region compared to the reference period, while other areas remain stable. ARISE-SAI shows higher increases in rainfall during the MAM season but lower increases during the JJAS and OND seasons compared to SSP2-4.5. Overall, the study’s findings suggest that SAI technology could have a clear effect in reducing temperatures in Eastern Africa, both in the near- and mid-term futures. However, its impact on rainfall varies by region and season, indicating that further simulations with a wider range of scenarios and analyses are required to assess the robustness of these results. The results of this study should be interpreted cautiously since they are specific to the approach of SAI applied, the modelling experiments employed, and the scenarios considered. |
| format | Article |
| id | doaj-art-8bb1dd04e08548ad81106da9172eebb8 |
| institution | OA Journals |
| issn | 2624-9553 |
| language | English |
| publishDate | 2025-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Climate |
| spelling | doaj-art-8bb1dd04e08548ad81106da9172eebb82025-08-20T02:25:59ZengFrontiers Media S.A.Frontiers in Climate2624-95532025-04-01710.3389/fclim.2025.15222351522235Simulated response of the climate of eastern Africa to stratospheric aerosol interventionHerbert O. Misiani0Hussen S. Endris1Franklin J. Opijah2Jully O. Ouma3Betty N. Barasa4Mari R. Tye5Mari R. Tye6Douglas G. MacMartin7Climate Diagnostic and Prediction Unit, IGAD Climate Prediction and Applications Centre, Nairobi, KenyaClimate Diagnostic and Prediction Unit, IGAD Climate Prediction and Applications Centre, Nairobi, KenyaMeteorology Unit, Department of Earth and Climate Sciences, University of Nairobi, Nairobi, KenyaClimate Diagnostic and Prediction Unit, IGAD Climate Prediction and Applications Centre, Nairobi, KenyaLogistics Unit World Food Program, Juba, South SudanClimate and Global Dynamics Laboratory, NSF National Center for Atmospheric Research, Boulder, CO, United StatesWhiting School of Engineering, Johns Hopkins University, Baltimore, MD, United StatesDepartment of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United StatesEastern Africa is vulnerable to extreme climate events, including droughts and floods, which are expected to become more frequent and intense in the future. This paper evaluates the potential of solar radiation management (SRM) with stratospheric aerosol injection (SAI) to influence the projected climate, including extreme events, over the region. The study utilized climate simulation outputs from the Community Earth System Model version 2 with the Whole Atmosphere Community Climate Model (CESM2-WACCM6) to assess future climate changes under two scenarios: one without Solar Aerosol Injection (SAI) following the SSP2-4.5 emissions pathway, and another with SAI, based on the first set of simulations from the Assessing Responses and Impacts of Solar Climate Intervention on the Earth System with Stratospheric Aerosol Injection (ARISE-SAI) project. The analysis of model performance was conducted for the 1981–2010 period, while future changes were assessed over two climatological periods: the near-term (2035–2054) and the mid-term (2050–2069). Changes in extreme temperatures and rainfall events were evaluated using four extreme indices: two for temperature (WSDI and DTR) and two for rainfall (CDD and CWD). Additionally, the Standardized Precipitation-Evapotranspiration Index (SPEI) was used to assess changes in the frequency of extreme wet and dry events. In the historical period, there is good agreement between the observed and simulated data in representing the spatial distribution of temperature and rainfall over the region, despite the slight overestimation and underestimation by the model in some areas. The model effectively captures the seasonal cycles of rainfall and temperature over the cities of interest. Analysis of future projections indicates that temperatures are projected to rise consistently in the future under the SSP2-4.5 scenario. However, SAI produces a steady trend in the four cities, suggesting SAI’s potential to counteract warming in Eastern Africa. Rainfall is projected to increase in the equatorial region compared to the reference period, while other areas remain stable. ARISE-SAI shows higher increases in rainfall during the MAM season but lower increases during the JJAS and OND seasons compared to SSP2-4.5. Overall, the study’s findings suggest that SAI technology could have a clear effect in reducing temperatures in Eastern Africa, both in the near- and mid-term futures. However, its impact on rainfall varies by region and season, indicating that further simulations with a wider range of scenarios and analyses are required to assess the robustness of these results. The results of this study should be interpreted cautiously since they are specific to the approach of SAI applied, the modelling experiments employed, and the scenarios considered.https://www.frontiersin.org/articles/10.3389/fclim.2025.1522235/fullstratospheric aerosol injectiongeoengineeringclimateeastern Africaextremes |
| spellingShingle | Herbert O. Misiani Hussen S. Endris Franklin J. Opijah Jully O. Ouma Betty N. Barasa Mari R. Tye Mari R. Tye Douglas G. MacMartin Simulated response of the climate of eastern Africa to stratospheric aerosol intervention Frontiers in Climate stratospheric aerosol injection geoengineering climate eastern Africa extremes |
| title | Simulated response of the climate of eastern Africa to stratospheric aerosol intervention |
| title_full | Simulated response of the climate of eastern Africa to stratospheric aerosol intervention |
| title_fullStr | Simulated response of the climate of eastern Africa to stratospheric aerosol intervention |
| title_full_unstemmed | Simulated response of the climate of eastern Africa to stratospheric aerosol intervention |
| title_short | Simulated response of the climate of eastern Africa to stratospheric aerosol intervention |
| title_sort | simulated response of the climate of eastern africa to stratospheric aerosol intervention |
| topic | stratospheric aerosol injection geoengineering climate eastern Africa extremes |
| url | https://www.frontiersin.org/articles/10.3389/fclim.2025.1522235/full |
| work_keys_str_mv | AT herbertomisiani simulatedresponseoftheclimateofeasternafricatostratosphericaerosolintervention AT hussensendris simulatedresponseoftheclimateofeasternafricatostratosphericaerosolintervention AT franklinjopijah simulatedresponseoftheclimateofeasternafricatostratosphericaerosolintervention AT jullyoouma simulatedresponseoftheclimateofeasternafricatostratosphericaerosolintervention AT bettynbarasa simulatedresponseoftheclimateofeasternafricatostratosphericaerosolintervention AT marirtye simulatedresponseoftheclimateofeasternafricatostratosphericaerosolintervention AT marirtye simulatedresponseoftheclimateofeasternafricatostratosphericaerosolintervention AT douglasgmacmartin simulatedresponseoftheclimateofeasternafricatostratosphericaerosolintervention |