Future climate projections in the global coastal ocean

Resilient coastal communities and sustainable marine economies require actionable knowledge to plan for and adapt to emerging and potential future climate change, particularly in relation to ecosystem services and coastal hazards. Such knowledge necessarily draws heavily on coastal ocean modelling of future climate impacts, using a great diversity of both global and regional approaches to explore multiple societal challenges in coastal and shelf seas around the world. In this paper, we explore the challenges, solutions and benefits of developing a better coordinated and global approach to future climate impacts modelling of the coastal ocean, in the context of the UN Decade of Ocean Science for Sustainable Development project Future Coastal Ocean Climates (FLAME; part of the CoastPredict programme). Particularly, we address the need for diverse modelling approaches to meet different societal challenges, how regions can be harmonised through clustering and typology approaches, and how coordination of experimental designs can promote a better understanding of uncertainties and regional responses. Improved harmonisation of future climate impact projections in the global coastal ocean would allow sectoral and cross-sectoral global scale risk assessments, improve process understanding and help build capacity in under-represented areas such as the global south and small island developing states. We conclude with a proposed framework for a Global Coastal Ocean Model Intercomparison Project.