Contrasting hydro-climatic trends and drought dynamics in Ethiopia and South Africa under climate change

Abstract Climate change profoundly impacts hydro-climatic systems, altering precipitation, temperature, and drought dynamics. This study investigates contrasting trends in Ethiopia and South Africa under historical and future scenarios (SSP2-4.5, and SSP5-8.5) using CMIP6 datasets. The analysis encompasses national averages and regional clusters to capture both spatial and temporal variability. In Ethiopia, annual precipitation increases by 1.2 mm/year under SSP2-4.5 and 2.5 mm/year under SSP5-8.5, potentially benefiting agriculture but elevating flood risks. Conversely, South Africa experiences decline in precipitation of 0.25 mm/year and 0.32 mm/year under SSP2-4.5 and SSP5-8.5, respectively, likely to exacerbate water scarcity and compromising agricultural resilience. Both countries see substantial increases in potential evapotranspiration (PET) and temperature extremes. Ethiopia’s PET rises by 0.67 mm/year and 0.97 mm/year, while South Africa’s PET increases by 1.14 mm/year and 1.83 mm/year. Temperature increases in Ethiopia are more pronounced in minimum temperatures, while South Africa shows a similar rate of increase in both maximum and minimum temperatures. Drought analysis using SPEI and SPI indices reveals divergent trends: Ethiopia generally experiences decreased drought occurrence, severity and frequency, whereas South Africa faces increased drought occurrences and its properties, particularly under high emissions. These trends vary across clusters, highlighting the need for tailored adaptation strategies in each region. Despite its comprehensive approach, the study acknowledges limitations, including uncertainties in climate model projections and the need for more localized data. Understanding the interplay between hydro-climatic variables and their extremes is essential for effective adaptation. Ethiopia should strengthen flood management and promote soil conservation practices, while South Africa should focus on water conservation. Both nations must integrate climate projections into planning, enhance early warning systems, and foster public–private partnerships for successful adaptation.