Assessment of Future Climate under CMIP6-Based Shared Socioeconomic Pathways (SSP) Scenarios in the Nouhao Sub-Basin, East-Central Burkina Faso

Abstract

This study assesses future climate projections for the Nouhao sub-basin at three key temporal horizons (2050, 2070, and 2100) under different SSP scenarios. Using recent precipitation and temperature data from 17 global CMIP6 models downscaled at a 0.25˚ resolution, the multi-model approach was applied to capture the range of future climate changes. The CMIP6 models were validated against CHIRP and ERA5 reference datasets, demonstrating strong performance for precipitation (r = 0.76, RMSE = 29.14 mm, MAE = 24.72 mm) and moderate accuracy for temperature (r = 0.27, RMSE = 0.30˚C, MAE = 0.26˚C), with all metrics calculated at the annual timescale. Results indicate a projected 35% increase in precipitation across the basin by 2100, alongside a gradual temperature rise of 1˚C to 4˚C. However, the analysis reveals significant uncertainties, particularly for temperature and precipitation projections, with some individual models suggesting a slight decline in precipitation and even cooling trends over the basin. These discrepancies underscore the challenges in modelling regional climate impacts and the need for more robust projections. These findings highlight the urgency of developing basin-specific adaptation strategies, focusing on agriculture, water management, and climate resilience. Policymakers are thus provided with critical insights to guide proactive decision-making, ensuring that the basin is better prepared for future climate challenges.