Submitted | Projected Changes in Precipitation and Temperature for Ethiopian Coffee Growing Regions using CMIP6 Multi-Model Ensembles
- Jul 31, 2025
- 2 min read
Fenet Belay, Weyessa Garedew, Colleta Gandidzanwa, Alemayehu Oljira,
Judith Adejoke Falola-Olasunkanmi, Jacob Agyekum, Jabulani Nsyengere, Wakjira Takala Dbaba
Research article submitted to Journal of Theoretical and Applied Climatology
Abstract: Hydro-climatic and thermal changes are becoming increasingly pronounced in the Ethiopian highlands, posing a risk to coffee-producing landscapes where Coffea arabica is a major source of livelihoods. This research focuses on developing high-resolution climate projections for the major coffee-growing zones of southwestern and Western Ethiopia using a bias-corrected CMIP6 multi-model ensemble under SSP2-4.5 and SSP5-8.5 scenarios. The bias-corrected ensemble using empirical quantile mapping substantially improved agreement with observations for precipitation (PBIAS = −0.35%, NSE = 0.91, R² = 0.96) and for both temperature extremes (Tmax NSE = 0.92; Tmin NSE = 0.75). Projections indicate a warming signal across all periods, with Tmax increasing by 1.01–1.72 °C (2031–2060) and 1.72–3.27 °C (2071–2100), while Tmin rises more sharply by 1.26–2.00 °C and 2.00–3.94 °C under SSP2–4.5 and SSP5–8.5, respectively. This asymmetric warming implies a reduced diurnal temperature range, intensifying nighttime heat stress with likely consequences for coffee respiration, carbohydrate allocation, yield stability, and quality. Mean annual precipitation is projected to increase by 3.5–9.4% under SSP2–4.5 and 18.0–23.7% under SSP5–8.5; however, rainfall declines are projected during the peak rainy months (June–July), signalling heightened seasonal water stress despite overall wetting. Spatial patterns reveal strong topographic controls, with wetter and cooler highlands contrasting with warmer, lower-lying areas where thermal stress is amplified. The combined risks of rising temperatures and rainfall redistribution underscore the urgent need for climate-resilient coffee strategies, including shade-based agroforestry, improved soil and water conservation, and heat-tolerant varieties to safeguard Ethiopia’s highland coffee systems.
Keywords: climate projections, CMIP6 projections, coffee agroecosystem, Statistical downscaling,
