Spatiotemporal climate trends and policy assessment in Ethiopia’s Lake Tana Basin amid global carbon dioxide emissions

Climate change, predominantly driven by escalating global CO2 emissions, is significantly altering global and regional weather patterns. The Lake Tana Basin, a critical ecological and agricultural zone, exhibits high vulnerability to this climatic variability. This study examined long-term trends in rainfall (1900 – 2023) and temperature (1901 – 2022) using the CenTrends and CRU datasets, along with the spatial variability of rainfall and temperature (1981 – 2022) based on the National Aeronautics and Space Administration data. It also investigated the relationship between climate variables and global CO2 emissions (using the EDGAR dataset; 1970 – 2022) and assessed the efficacy of local climate policies. The findings revealed pronounced spatiotemporal variability. A significant decrease in crucial summer (Kiremt) rainfall was observed (Sen’s slope: −0.335 mm/year; p=0.011), whereas November rainfall displayed a significant increasing trend (Sen’s slope: 0.045 mm/month; p=0.04), contributing to rising autumn rainfall. Temperatures are rising unequivocally (p<0.05). Notable spatial variability was also observed across different agroecological zones – for instance, the Gondar station reported an annual rainfall with a coefficient of variation of 32.6% compared to 22.3% at Injibara. A significant decline in rainfall was observed in Woreta and Delgi, with Mann–Kendall trend values of −0.247 (p=0.022) and −0.265 (p=0.014), respectively. A robust, statistically significant positive correlation (r = 0.743; p<0.01) was established between global CO2 emissions and local temperature changes over 53 years. An in-depth policy review identified substantial challenges that impede effective climate action. These results underscore the urgent need for strengthening policy implementation and promoting targeted, location- and season-specific adaptation and mitigation strategies. These include adopting climate-smart agricultural practices, improving carbon sequestration capacity, and aligning local climate actions with global mitigation efforts. Participation in global climate agreements and initiatives, integrated with local actions that contribute to global emission reduction targets, is essential for ensuring long-term sustainability and enhancing community resilience.