Blue Finance

This chapter examines blue finance as an emerging branch of climate finance that targets the water-ocean-coastal nexus and addresses persistent underinvestment in ocean health and sustainable ocean economy outcomes. Building on the conceptual distinction between blue and green finance, the chapter explains why blue finance faces a distinctive constraint set—common-pool resource problems, public-good benefits, cross-boundary externalities, and higher monitoring and enforceability demands—and why these features raise both bankability and credibility challenges. It then develops a functional typology of blue finance instruments, spanning labeled use-of-proceeds products (blue bonds and loans), blended finance and guarantees, conservation-linked debt operations (including debt-for-nature-style conversions), natural capital and ecosystem service finance, and resilience-focused risk transfer. The chapter illustrates these channels through three representative cases—Seychelles’ sovereign blue bond, Belize’s conservation-linked debt conversion, and SABESP’s sanitation-linked blue issuance—highlighting how de-risking layers, institutional design, and Measurement, Reporting, and Verification (MRV) frameworks shape feasibility and integrity. The policy discussion emphasizes definitional discipline to prevent blue-washing, public investment in MRV capacity as a catalytic input to private capital mobilization, and integrated land-to-sea governance to build credible project pipelines.