Understanding climate-driven impacts on the multivariate global wind-wave climate is paramount to effective offshore/coastal climate adaptation planning. However, the use of single-method ensembles and variations arising from different methodologies has resulted in unquantified uncertainty amongst existing global wave climate projections. Here, assessing the first coherent, community-driven, multi-method ensemble of global wave climate projections, we demonstrate widespread ocean regions with robust changes in annual mean significant wave height and mean wave period of 5-15% and shifts in mean wave direction of 5-15 degrees, under a high-emission scenario. Approximately 50% of the world's coastline is at risk from wave climate change, with similar to 40% revealing robust changes in at least two variables. Furthermore, we find that uncertainty in current projections is dominated by climate model-driven uncertainty, and that single-method modelling studies are unable to capture up to similar to 50% of the total associated uncertainty.
Morim, J; Hemer, M; Wang, XLL; Cartwright, N; Trenham, C; Semedos, A; Young, I; Bricheno, L; Camus, P; Casas-Prat, M; Erikson, L; Mentaschi, L; Mori, N; Shimura, T; Timmermans, B; Aarnes, O; Breivik, O; Behrens, A; Dobrynin, M; Menendez, M; Staneva, J; Wehner, M; Wolf, J; Kamranzad, B; Webb, A; Stopa, J; Andutta, F
Robustness and uncertainties in global multivariate wind-wave climate projections
Nature Climate Change