“Blue carbon” is the type of carbon that is stored by coastal wetland vegetation such as mangroves, seagrasses and salt marsh grasses. While protection and restoration of coastal ecosystems has a relatively low global mitigation potential due to their small distribution, these ecosystems can store carbon at high rates per hectare. Nature4Climate reports that the greatest cost-effective emissions reduction potential in the wetlands biome was found to be through avoided peatland impacts—the protection of marshes and peat bogs are a more effective long-term carbon store than forests. Although wetland systems are often highly efficient in sinking carbon, they are also threatened by conversion worldwide.
In addition to avoided peatland impacts and peatland restoration, coastal restoration, and avoided coastal impacts can yield carbon emission reduction benefits. IUCN’s Coastal Blue Carbon report details funding mechanisms and case studies of wetland focused carbon management projects worldwide, highlighting great potential to link blue carbon with other resource management outcomes such as biodiversity and water quality benefits. To achieve blue carbon sequestration outcomes Macreadie et al. report that three key environmental processes must be managed: nutrient inputs, bioturbation and hydrology. When these processes are altered by human actions, such as eutrophication of coastal ecosystems, it can result in large amounts of CO2 and methane being released back into the atmosphere. Therefore, growing evidence suggests that managing these three processes can increase long-term storage capacity in wetland systems. By identifying carbon mitigation management opportunities across biomes, land trusts can connect emerging best practices to long-standing stewardship approaches to further conservation objectives locally that yield critical global carbon reduction achievements.