Assessing the risk of carbon dioxide emissions from blue carbon ecosystems

“Blue carbon” ecosystems, which include tidal marshes, mangrove forests, and seagrass meadows, have large stocks of organic carbon (C_org) in their soils. These carbon stocks are vulnerable to decomposition and – if degraded – can be released to the atmosphere in the form of CO₂. We present a framework to help assess the relative risk of CO₂ emissions from degraded soils, thereby supporting inclusion of soil C_org into blue carbon projects and establishing a means to prioritize management for their carbon values. Assessing the risk of CO₂ emissions after various kinds of disturbances can be accomplished through knowledge of both the size of the soil C_org stock at a site and the likelihood that the soil C_org will decompose to CO₂.