ABSTRACT
Carbon (C) markets provide an incentive for new projects and activities that result in net greenhouse gas benefits. Accounting for methane emissions is critical for blue C projects because of the high global warming potential of methane relative to C dioxide and the large variation in methane emissions rates. Credit over-allocation to seagrass meadows or other blue C systems would devalue legitimate offset credits. The chapter addresses concerns about potential offset-credit misallocation in seagrass blue C projects, which may result from estimating long-term C accumulation by extrapolating sediment C burial rates. The Verified C Standard (VCS) is the largest C standard in the agriculture, forestry, and other land use sector. The VCS methodologies for tidal wetland and seagrass restoration and conservation provide greenhouse gas accounting procedures for restoration, creation, and conservation of marshes, mangroves, seagrasses, and forested tidal wetlands. Allochthonous C is C that was removed from the atmosphere outside of the project area and transported into the project area.
