SIMULATING FUTURE CLIMATE CHANGES UNDER THE SHARED SOCIOECONOMIC PATHWAY SCENARIOS: A CASE OF THE BLACK VOLTA BASIN OF GHANA

AMOS TIEREYANGN KABO-BAHSarah Elikplim Siabi^*Ebenezer K. SiabiNana Asirifi CobbinaWisdom Bruce Ahiada

• University of Energy and Natural Resources, Sunyani, Ghana

This study assessed the potential future impacts of climate change on Ghana's Black Volta Basin (BVB) using projections from 14 models under four CMIP6 scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5). The ensemble bias-corrected data consistently outperformed both individual bias-corrected and raw GCM data, particularly for precipitation, where the coefficient of determination (R²) improved significantly from as low as 0.001 in raw data to between 0.87 and 0.99 after correction. Bias-corrected temperature projections, both minimum and maximum, were even more reliable than those for precipitation. By 2050, the BVB is expected to experience substantial warming and declining rainfall, with precipitation projected to fall in most months except August and September across all scenarios. Temperature increases are especially notable under SSP2-4.5, SSP3-7.0, and SSP5-8.5, with monthly averages for maximum and minimum temperatures rising between 1°C and 7.5°C. These changes pose serious risks to livelihoods, particularly affecting agriculture, water resources, and energy production. The hydroelectric sector, including the Bui and Akosombo dams, is projected to face reduced water inflows, potentially leading to widespread power outages. Moreover, the projected impacts are not temporally uniform. Seasonal analyses indicate that the dry season (January to March) will experience the most severe reductions in rainfall, while localized increases are observed during the late rainy season (August to September), particularly in northern parts of the basin. Spatial disparities in temperature trends such as higher warming rates in the north. This poses a direct threat to communities dependent on these dams for electricity and water. Northern parts of the basin may see annual rainfall decline from historical norms of 1000-1400 mm to 800-900 mm under SSP5-8.5, worsening water scarcity. At sites like Babile, temperatures could reach as high as 38°C by 2050, far above historical averages, likely increasing the frequency of extreme weather events. The study highlights the urgent need for adaptive measures to mitigate these impacts. It recommends the adoption of drought-resistant crops, improved water management strategies, revised energy policies, and investments in climate-resilient infrastructure, forecasting tools, and sustainable agriculture to enhance long-term resilience in the BVB.