The document discusses the advantages and challenges of using a river basin approach for climate change adaptation. Some key advantages include maintaining ecosystem services, enabling upstream-downstream cooperation, and facilitating integrated human and ecosystem adaptation planning. Challenges include misalignments between river basins and political boundaries, and the need for long-term funding and flexible approaches given climate uncertainties. The document also provides an example vulnerability assessment conducted in Nepal's Gandaki river basin using the "Flowing Forward" methodology.