Blue Carbon in Nationally Determined Contributions (NDCs): Opportunities and Challenges

Abstract Coastal “blue carbon” ecosystems — mangroves, tidal marshes, and seagrasses — store large amounts of carbon, particularly in soils, and can contribute to climate mitigation while delivering important adaptation and livelihood co-benefits. Incorporation of coastal wetlands into Nationally Determined Contributions (NDCs) under the Paris Agreement offers countries a nature-based pathway to increase mitigation ambition. However, integrating blue carbon into NDCs raises methodological, institutional, and governance challenges: consistent measurement, reporting and verification (MRV) aligned with IPCC guidance; accounting for non-CO₂ fluxes and permanence; securing finance and tenure clarity; and ensuring equitable outcomes for coastal communities. This review synthesizes scientific evidence and policy guidance, evaluates the current status of blue carbon in NDCs, and proposes practical recommendations to improve integration of blue carbon into national climate strategies. Keywords: Blue carbon; coastal wetlands; mangroves; tidal marshes; seagrasses; Nationally Determined Contributions (NDCs); climate change mitigation; MRV; IPCC guidelines; nature-based solutions