Coastal sustainability depends on how economic and coastline responses to climate change affect each other

Human-induced climate change is predicted to accelerate sea level rise and alter storm frequency along the US east coast. Rising sea level will enhance shoreline erosion, and recent work indicates changing storm patterns and associated changes in wave conditions can intensify coastal erosion along parts of a coastline. Investigations of coastal response to climate change typically consider natural processes in isolation - neglecting repeated changes to the coastline from human actions, primarily through shoreline nourishment projects, which add sand to the shoreline to counteract erosion. In a model coupling economically driven shoreline nourishment with wave-and sea level rise-driven coastline change, and accounting for dwindling sediment resources for nourishment, coastline response depends dramatically on the relationship between patterns of property value and erosion. Simulations show that when nourishment costs rise with depletion of sand resources, coastline change is tied to the interaction between patterns of erosion and property value. Simulations show that when high property values align with highly erosive locations, sand resources are depleted rapidly and nourishment in lower property value towns is quickly abandoned. Although our model simulates a particular coastal morphology, the result that future behavior of the coastline and the economic viability of nourishment in a given town depend on the regional interaction between patterns of property value and erosion is likely applicable to many coastal configurations. More broadly, coupling economic and physical models reveals equity and sustainability implications of coastal climate adaptation as well as patterns of coastline change that a physical model alone would overlook. Citation: McNamara, D. E., A. B. Murray, and M. D. Smith (2011), Coastal sustainability depends on how economic and coastline responses to climate change affect each other, Geophys. Res. Lett., 38, L07401, doi:10.1029/2011GL047207.