WP 6: Modelling and scenarios

The potential of coastal vegetated ecosystems to mitigate climate change through carbon dioxide removal depends on how these systems can be maintained and expanded in the future under different climate conditions. In Work Package 6, simulations will be computed using a state-of-the-art Earth system model, based on the data from Work Packages 1-5, to help provide a global understanding of the historical and current carbon sequestration potentials of vegetated coastal ecosystems. Using the Flexible Ocean and Climate Infrastructure Model, called FOCI, which includes a horizontal resolution of 0.5° and an embedded high-resolution (1/10°) nest for the North Atlantic and European seas, calculations for future carbon sequestration potentials of vegetation-rich coastal ecosystems can be extended to include expansion and climate change scenarios. As coastal vegetated ecosystems cannot yet be dynamically simulated in Earth system models due to resolution limitations at the coasts, new parameterizations representing coastal vegetated ecosystems at the land-ocean interface will be developed. These parameterizations will account for the effects of coastal vegetated ecosystems on carbon and other biogeochemical cycles and include a dependence on environmental conditions that can impact the stability of carbon stores. Remote sensing products generated in Work Package 3 will also be integrated to provide the model with data on the spatial distribution of coastal vegetated ecosystems. The idealized coastal vegetated ecosystem expansion scenarios that are developed will include both an estimated maximum carbon dioxide removal scenario based on biogeophysical constraints and one that accounts for other considerations such as sustainability and socio-economics. These coastal vegetated ecosystem scenarios will then be run with two contrasting 21^st century CMIP6 CO₂ emission scenarios, i.e., to simulate futures with low or high climate change. A specific focus of the analyses will be on the efficacy of coastal vegetated ecosystem for carbon dioxide removal to mitigate climate change by accounting for global carbon cycle feedbacks and any associated side- and cross-boundary effects. Findings will support recommendations in Work Package 7.