Towards holistic global coastal flood risk assessments including Nature-based Solutions

In the coming century, people in low-lying coastal urban areas are projected to face an increase in coastal flood risk due to increases in, for example, urban development, sea-level rise, subsidence, and degradation of foreshore vegetation. To implement and raise awareness of coastal climate change adaptation, it is important to better understand the effectiveness of coastal flood risk adaptation strategies, such as Nature-based Solutions and hybrid strategies. Nature-based adaptation in coastal areas, such as vegetation on the foreshore, is showing potential to mitigate the impacts of climate change. Unlike previous studies of Nature-based Solutions, we provide a quantitative assessment of the benefits of combining Nature-based Solutions and structural measures, so-called hybrid solutions, in terms of reduced economic damage, exposed population, and social vulnerability indicators such as poverty dynamics. We show that including hybrid solutions in coastal management strategies benefits people living in poverty more than other people, because the former group are often more prone to coastal flooding. As such, Nature-based and hybrid solutions in lower and middle income countries could contribute to the resilience of people in poverty.