Reda et al. (2026) Intensification of drought characteristics in Africa’s Great Green Wall countries under climate change

Identification

• Journal: Regional Environmental Change
• Year: 2026
• Date: 2026-02-12
• Authors: Kidane Welde Reda, Yongdong Wang, You Yuan, Hintsa Libsekal Gebremariam, Gebru Eyasu
• DOI: 10.1007/s10113-026-02548-4

Research Groups

• National Engineering Technology Research Center for Desert-Oasis Ecological Construction, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
• Tigray Agricultural Research Institute, Mekelle, Ethiopia

Short Summary

This study projects the intensification of drought characteristics (area, duration, frequency, and intensity) across Africa's Great Green Wall (AGGW) under various climate change scenarios, revealing significant increases in droughted area, particularly under high-emission pathways, which threatens ecosystems and livelihoods.

Objective

• To assess the projected impacts of climate change on spatiotemporal drought characteristics (area, events, duration, frequency, and intensity) across Africa's Great Green Wall (AGGW) region under different Shared Socioeconomic Pathways (SSP126, SSP370, SSP585).

Study Configuration

• Spatial Scale: Africa's Great Green Wall (AGGW) member countries (Djibouti, Eritrea, Ethiopia, Sudan, Chad, Niger, Nigeria, Mali, Burkina Faso, Mauritania, and Senegal), located in the Sahel region between 17.53° W and 48.0° E longitude and 3.40° and 27.30° N latitude.
• Temporal Scale:
  • Historical baseline: 1981–2014
  • Projection windows: 2020s (2014–2043), 2050s (2041–2070), and 2080s (2071–2099)
  • Overall analysis period: 1981–2100

Methodology and Data

• Models used:
  • Standardized Precipitation Evapotranspiration Index (SPEI) at a 12-month accumulation timescale (SPEI-12).
  • FAO-56 Penman–Monteith formulation for Potential Evapotranspiration (PET).
  • Ensemble of five bias-corrected and downscaled Global Climate Models (GCMs) from the ISIMIP3b dataset (IPSL-CM6A-LR, MRI-ESM2-0, GFDL-ESM4, MPI-ESM1-2-HR, UKESM1-0-LL).
• Data sources:
  • Inter-Sectoral Impact Model Intercomparison Project phase 3b (ISIMIP3b) dataset for climate variables (precipitation, mean temperature, solar radiation, relative humidity, wind speed).
  • Climatic Research Unit Time Series (CRU TS) dataset (v4.03) for observational baseline data and validation.
  • Shared Socioeconomic Pathways (SSP126, SSP370, SSP585) scenarios.

Main Results

• The droughted area in the AGGW region is projected to increase by 7.42%, 19.92%, and 28.94% by the end of the century (2080s) under SSP126, SSP370, and SSP585, respectively.
• Moderate droughted areas are expected to expand more rapidly than severe or extreme events, though severe and extreme droughts become increasingly relevant under higher emission scenarios and later time slices.
• Drought duration, frequency, and intensity are projected to rise throughout the twenty-first century, with larger changes observed under higher SSPs.
• Spatially, northern Mauritania, Mali, Niger, Chad, and Sudan are identified as hotspots likely to experience the greatest increases in drought risk (events, duration, frequency, intensity).
• Central and southern Ethiopia, and southern Nigeria and Niger are projected to experience relatively smaller changes in drought risk.
• December and July consistently show the highest increases in drought extent across all time windows and emission scenarios.
• The SPEI time series consistently indicates a significant decreasing trend across all future scenarios, with the decline becoming more pronounced from the early 2050s onward, implying increasing aridity.

Contributions

• Provides a comprehensive, multi-model, and scenario-based assessment of projected climate change impacts on various drought characteristics (area, events, duration, frequency, intensity) specifically for the Africa's Great Green Wall (AGGW) region.
• Integrates multiple climate models and drought indices to offer a robust understanding of future drought patterns, addressing limitations of previous single-model or historical observation-based studies.
• Offers science-based evidence to support planning, resource allocation, and climate adaptation strategies for the AGGW initiative, highlighting spatial and temporal hotspots of vulnerability.
• Advances scientific understanding of drought characteristics under regional climate change, supporting policymakers and stakeholders in strengthening resilience.

Funding

• "Silk Road Economic Belt" Ecological Construction Technology Demonstration National Base for International Science and Technology Cooperation.
• "Future Partner Network Special Project" of the International Partnership Program of the Chinese Academy of Sciences: "Study on the Desertification Control and Management System in Ethiopia" (072GJHZ2024252FN).
• Xinjiang Uygur Autonomous Region "Tianshan Talents" Program (2022TSYCCX0004).

Citation

@article{Reda2026Intensification,
  author = {Reda, Kidane Welde and Wang, Yongdong and Yuan, You and Gebremariam, Hintsa Libsekal and Eyasu, Gebru},
  title = {Intensification of drought characteristics in Africa’s Great Green Wall countries under climate change},
  journal = {Regional Environmental Change},
  year = {2026},
  doi = {10.1007/s10113-026-02548-4},
  url = {https://doi.org/10.1007/s10113-026-02548-4}
}