Global potential and limits of mangrove blue carbon for climate change mitigation

Despite the outsized role of mangrove forests in sustaining biodiversity, ecosystem function, and local livelihoods, the protection of these vital habitats through blue carbon financing has been limited.1,2 Here, we quantify the extent of this missed conservation and financial opportunity, showing that the protection of ∼20% of the world's mangrove forests (2.6 Mha) can be funded through carbon financing. Of these investible areas, 1.1-1.3 Mha can be financially sustainable over a 30-year time frame based on carbon prices of US$5-9.4 t-1CO2e. This contributes up to 29.8 MtCO2e year-1 and yields a return on investment of ∼US$3.7 billion per year. Our results point toward a disproportionately large potential of blue carbon finance that can be leveraged to meet national-level climate mitigation goals, particularly if combined with other conservation interventions that further safeguard carbon stocks and biodiversity in these irreplaceable forests. Robust information on return on investment highlights the potential for currently underutilized tropical coastal carbon credit projects.