From Rain to Rivers: A Systems Approach to the Global Hydrological Cycle in GEF Programming

This STAP paper examines how the global hydrological cycle connects climate, biodiversity, land, ecosystems, and human well-being across scales, and argues that water should no longer be managed primarily through fragmented, blue-water approaches focused on rivers, lakes, and aquifers alone. The paper highlights the growing importance of green water, atmospheric moisture flows, and land–atmosphere interactions in shaping water security, ecosystem resilience, and global environmental outcomes in an era of accelerating climate change and environmental degradation. It calls for the Global Environment Facility to adopt a more integrated, systems-based approach in GEF-9 programming by strengthening cross-focal area coherence, embedding hydrological linkages across projects and Integrated Programs, improving the evidence base on blue and green water dynamics, and advancing multi-level governance and cooperation to generate Global Environmental Benefits alongside broader socioeconomic and peace co-benefits.