Hydrology and Climate Change in Africa: Quaternary Dynamics, Contemporary Challenges, and Future Resilience Pathways

African hydrological systems demonstrate remarkable complexity and sensitivity to climate variability across multiple temporal scales, from profound Quaternary transformations to contemporary water security crises. This narrative review synthesizes paleoclimatic archives, observational data, remote sensing, and climate modeling to unravel the interaction between fluvial processes, water cycle dynamics, and anthropogenic pressures. The Quaternary reveals dramatic shifts, including the African Humid Period (AHP, 11.5–5 ka), which transformed the Sahara into a "pale-green" landscape with expanded wetlands and lakes, terminated by abrupt tipping points signaled by critical slowing down in proxy records. Contemporary systems face accelerating warming (+0.3°C/decade), intensifying hydrological extremes, and regionally divergent responses. East Africa shows reversed temperature-moisture correlations since the Holocene onset, while West African rivers exhibit nonlinear runoff sensitivity (3× reduction per rainfall unit decline). Also, land-use change rivals climate change as a hydrological disruptor, amplifying flood risks and groundwater depletion. Projected aridity, evaporative demands, and aquifer stress mandate integrated adaptation strategies leveraging remote sensing, nature-based solutions, and transboundary governance. We conclude that reconciling paleo-insights with modern vulnerabilities is essential for building resilient water futures across Africa’s diverse basins.