Land, rivers, oceans, the sea bed, atmosphere and humans all meet at the coast. Much effort has been expended on studying these in isolation; but one of the hardest outstanding problems in the environmental sciences is to understand how they act in combination, and all these components play into coastal flooding and erosion. While the occurrence, intensity and impacts of coastal flooding and erosion are projected to increase with climate change, future changes in regional sea level, storms, pluvial and fluvial inputs, coastal habitats, and their interrelations all lead to large epistemic uncertainties, with major socio-economic consequences. How will multiple terrestrial and marine drivers of extreme hydrodynamic conditions combine to control coastal flooding and erosion in the future? Issues with hard-engineered coastal defence schemes have driven advocacy of "natural solutions" via the protective services given by coastal habitats; what will their future vulnerability and efficacy be? How will these "natural solutions" perform on coasts that already have partial protection from traditional engineered coastal defences? CHAMFER will: deliver new knowledge and understanding to answer these questions; provide tools to analyse the efficacy of future "natural solutions"; work with government departments, public sector organisations, and industry users to inform and support coastal adaptation and resilience-building options.