Wetland restoration occurs sporadically throughout the world—primarily to create wildlife habitat, restore water quality and quantity levels, and provide storm protection and food production. However, wetland restoration also provides the additional benefits of greenhouse gas (GHG) emission reductions and climate change mitigation.

This methodology outlines procedures to estimate net greenhouse gas emission reductions and removals resulting from project activities implemented to restore tidal wetlands. Such activities may include creating, restoring, and/or managing hydrological conditions, sediment supply, salinity characteristics, water quality, and/or native plant communities. Accordingly, this methodology is applicable to a wide range of project activities aimed at restoring and creating tidal wetlands, and emission reductions and removals are estimated primarily based on the ecological changes that occur as a result of such activities (e.g., increased vegetative cover, changes to water table depth).

This methodology also addresses the potential for the establishment of woody vegetation. Project activities are expected to generate GHG emission reductions and removals through:

• Increased biomass.
• Increased autochthonous soil organic carbon.
• Reduced methane and/or nitrous oxide emissions due to increased salinity or changing land use.
• Reduced carbon dioxide emissions due to avoided soil carbon loss.

This methodology is applicable to projects located anywhere in the world, and to all tidal wetland systems—tidal forests, tidal marshes, and seagrass meadows. An activity method is used for the additionality assessment of projects located in the United States, and a project method is used for the additionality assessment of projects located outside the United States. A project method is used with respect to the crediting baseline for all projects.