Abstract
The intensification of soil moisture drought events is an expected consequence of anthropogenic global warming. However, the implication of 1.5–3 °C global warming on these events remains unknown over North Africa and the Sahel region, where soil moisture plays a crucial role in food security that largely depends on rainfed agriculture. Here, using a multi-model ensemble from the Inter-Sectoral Impact Model Intercomparison Project phase 2b, we estimate the changes in the spatiotemporal characteristics of soil moisture drought events under increased global mean temperature. A 3 °C global warming results in multi-year (up to 19 years) mega-drought events over North Africa compared to a maximum drought duration of 12 years under the 1.5 °C Paris Agreement target. These events are projected to transform from historically severe droughts into exceptional droughts and extend over an area that is 32% larger under 3 °C compared to that under 1.5 °C. Global warming also leads to a high intensification of Sahelian drought extremes, in particular, their duration (from 24 to 82 months between 1.5 and 3 °C) over the western parts and their severity everywhere. Even though the results highlight substantial uncertainties arising from climate forcing and impact models, the projections indicate a tendency toward unprecedented exacerbation of soil moisture droughts that could pose serious threats to food security of North African and Sahelian societies in the absence of effective mitigation and adaptation.
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Data availability
Monthly soil moisture projections are available via the ISIMIP ESGF server (http://isimip.org/outputdata/isimip-data-on-the-esgf-server/).
Code availability
Code supporting the findings of this study is available from the Department of Computational Hydrosystems at the Helmholtz Centre for Environmental Research repository at https://git.ufz.de/chs/progs/SMI. Results data and code written to generate the figures are available from the corresponding author upon request.
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Acknowledgements
The authors are grateful to the Inter-Sectoral Impact Model Intercomparison Project modeling groups and the cross-sectoral science team for their roles in producing, coordinating, and making available the ISIMIP models output. AE acknowledges support from Centre National pour la Recherche Scientifique et Technique (CNRST), Programme de Bourses d’Excellence de Recherche scholarship N°10UIZ2019. This study was carried out within the context of the CHARISMA project with the assistance of the Hassan 2 Academy of Sciences and Techniques and Ibn Zohr University. We would like to thank Sifeddine Afaf for proofreading the manuscript.
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AE, YP, ZEM, and LB conceived and designed the study. AE analyzed the data. All authors provided critical insights on the results and interpretation. AE drafted the manuscript, with a substantial contribution from YP, AC, AS, ST, and LB.
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Elkouk, A., El Morjani, Z.E.A., Pokhrel, Y. et al. Multi-model ensemble projections of soil moisture drought over North Africa and the Sahel region under 1.5, 2, and 3 °C global warming. Climatic Change 167, 52 (2021). https://doi.org/10.1007/s10584-021-03202-0
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DOI: https://doi.org/10.1007/s10584-021-03202-0