The potential for mangrove and seagrass blue carbon in Small Island States

Blue carbon is attracting substantial interest as a natural climate solution. Focus has been on countries with large blue carbon stocks, though the high carbon densities of blue carbon ecosystems make them suitable for Small Island States with small coastal habitats. Small Island States hold 1806–2892 Tg of blue carbon, and mangroves alone offset >10% of land use emissions for 11 Small Island States, highlighting their potential contribution to national climate change mitigation if they are protected and restored. However, <10% of Small Island States have incorporated blue carbon into their National Greenhouse Gas Inventories or Forest Reference Emissions Levels, only 23% have quantitative and measurable blue carbon targets, and 36% have no mention of blue carbon at all. There is immense scope to implement robust blue carbon targets and actions in many Small Island States, with Nationally Determined Contributions to the Paris Agreement being a key policy lever.