Research | Projected changes in precipitation and temperature for ethiopian coffee growing regions using CMIP6 multi-model ensembles

Fenet Belay^1,2, Weyessa Garedew³, Colleta Gandidzanwa⁴, Alemayehu Oljira⁵,

Judith Adejoke Falola-Olasunkanmi ⁶, Jacob Agyekum⁷, Jabulani Nyengere⁸ 

& Wakjira Takala Dibaba^9,10

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1 Department of Rural Development and Agricultural Extension, College of Agriculture and Veterinary Medicine, Jimma University, P.O. Box: 378, Jimma, Ethiopia; 2 Future Africa, University of Pretoria, Pretoria, South Africa; 3 Ethiopian Agricultural Transformation Institute, Addis Ababa, Ethiopia; 4 Faculty of Natural and Agricultural Sciences, Department of Agricultural Economics, Extension and Rural Development, University of Pretoria, Pretoria, South Africa; 5 Department of Agricultural Economics and Agribusiness Management, College of Agriculture and Veterinary Medicine, Jimma University, P.O. Box: 378, Jimma, Ethiopia; 6 Department of Crop Productions, Faculty of Agriculture, Kwara State University Malete, Kwara, Malete, Nigeria; 7 Council for Scientific and Industrial Research, Water Research Institute, Accra, Ghana; 8 Ndata School of Climate and Earth Sciences, Malawi University of Science and Technology, P.O. Box 5196, Limbe, Malawi;

9 Hydraulic and Water Resources Engineering, Faculty of Civil and Environmental Engineering, Jimma University, Jimma, Ethiopia; 10 Social-Ecological Systems, Policy and Strategy Lab, Dutse, 720101, Nigeria

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Abstract: The variability in the climate system is increasing in the Ethiopian highlands, posing risks to livelihoods dependent on coffee production in the regions dominated by Coffea Arabica Linnaeus. In this study, an ensemble of bias-corrected CMIP6 models under SSP2-4.5 and SSP5-8.5 scenarios was used to produce high-resolution climate projections in the coffee-growing zones in southwest and western Ethiopia. With good agreement for both temperature (Tmax/Tmin; NSE = 0.92/0.75; R² = 0.96/0.82) and precipitation (NSE = 0.91; R² = 0.96), the application of empirical quantile mapping substantially improved model simulation. Under all scenarios, the warming trend was statistically significant (p < 0.05), with projected increases in Tmax of 1.01 (1.37) °C (2031–2060) and 1.72(3.27) °C (2071–2100), and Tmin of 1.26(1.88) °C and 2.00(3.94) °C under SSP2–4.5(SSP5–8.5), scenarios. This asymmetric warming reduces diurnal temperature range and intensifies nighttime heat stress with implications for coffee respiration, carbohydrate allocation, yield stability, and bean quality. On the contrary, annual precipitation changes are statistically insignificant (p > 0.05). Seasonal analysis, however, shows that JJAS rainfall significantly decreased over the mid-century under SSP2-4.5 (p < 0.05), while MAM rainfall significantly increased during mid-century and reversed to significantly decline under late-century SSP5-8.5. The decrease in rainfall during the rainy season suggests increased intra-seasonal variation and potentially water stress, despite projected increase in mean annual precipitation by 3.47–9.44% and 18.01–23.74% under SSP2-4.5/SSP5-8.5, respectively. These results highlight the need for climate-resilient adaptation techniques, such as heat-tolerant coffee varietals, soil and water conservation, and shade-based agroforestry.

Keywords: Climate and Earth System Modelling, Climate Change, Climate-Change Adaptation, Climate Sciences, Earth Sciences, Drought, Agroecological Approaches in Coffee Production

Funding: This study was conducted under the Future Africa Research Leadership Fellowship (FAR-LeaF II), a two-year research-focused fellowship funded by the Carnegie Corporation of New York and implemented at Future Africa, University of Pretoria, South Africa. The funder had no role in the study design, data collection, analysis, interpretation of results, manuscript preparation, or the decision to publish.

Citation: Belay, F., Garedew, W., Gandidzanwa, C. et al. Projected changes in precipitation and temperature for ethiopian coffee growing regions using CMIP6 multi-model ensembles. Theor Appl Climatol 157, 659 (2026). https://doi.org/10.1007/s00704-026-06601-4

Contributions: Fenet Belay: Conceptualization, Methodology, Investigation, Data curation, Formal analysis, Writing – original draft, Writing – review & editing, Weyessa Garedew: Conceptualization, Methodology, Writing – review & editing. Colleta Gandidzanwa: Writing – review & editing, Alemayehu Oljira: Writing – review & editing, Judith Adejoke Falola-Olasunkanmi: Writing – review & editing, Jacob Agyekum: Writing – review & editing, Jabulani Nyengere: Conceptualization, Formal analysis, Writing – review & editing, Validation, Wakjira Takala Dibaba: Methodology, Formal analysis, Writing – review & editing.