Improving climate information through projecting climate change and variability in the Upper Awash Subbasin, Ethiopia

Climate change and variability have significantly impacted developing countries like Ethiopia, primarily due to a lack of accurate climatic information that is vital for effective planning and adaptation strategies. The study aimed to improve the reliability of climate information in Ethiopia, where insufficient information hinders mitigation and adaptation to climate change effects. The analysis utilized observational reference period data alongside CMIP6 (Coupled Model Intercomparison Project phase 6) General Circulation Model (GCM) data under various scenarios employing SD-GCM V2.0 for bias correction and statistical downscaling. The findings suggest that the highest maximum annual temperatures will rise by 2.03 °C under the SSP5–8.5 scenario. Mean annual rainfall is likely to increase by 23.5% and 5.3% over the projected period, both the highest and lowest recorded under SSP5–8.5. The coefficient of variation analysis revealed that most stations exhibited moderate and high annual and seasonal rainfall variability during the observation period. Meanwhile, the projected seasonal and annual rainfall displayed high variability compared to the observational reference period. However, all stations recorded less variation in yearly minimum and maximum temperatures throughout the study. While there is a substantial increase in average annual rainfall, there are still years with lower and higher yearly rainfall that likely led to drought and flooding in certain areas. In managing the droughts and floods expected due to climate change and variability, it is essential to implement mitigation and adaptation techniques with comprehensive disaster risk management strategies. Hence, the current study aims to improve the reliability of climate information in the UASB, Ethiopia.