Sea level rise implications on future inland migration of coastal wetlands

Abstract

Coastal wetlands provide essential ecosystem functions, including coastal protection, improvement in water quality and carbon sequestration, which are threatened due to sea level rise (SLR) – a well-documented aspect of anthropogenic climate change. While there are numerous articles on SLR impacts on wetlands, data about the interactions between natural or human-made barriers and future SLR projections e.g. coastal squeeze are still sparse. If wetlands are bounded by natural formations or human-made structures, coastal wetlands could be permanently lost in a warming climate. Here we delineate impacts of SLR on wetland inland migration under a changing climate in six locations around the world with a particular focus on the consequences of human-made structures along coastlines in Europe, specifically along the largest continuous coastal wetland system in the world, the Wadden Sea. Various locations around the world (North America, South America, Europe, Africa, Asia and Australia) were chosen to analyze the impacts of regional SLR on wetland dynamics under climate change scenario. Our results show that places like Bangladesh, India and Myanmar have much larger areas at risk with nearly 10% of their coastal wetlands, whereas the wetlands in northern Australia seem to have a low area at risk to be lost with not even 1%. For the North Sea coast, wetlands where we had access to data from human-made infrastructure, we show that due to the built infrastructure, the wetland areas do not have the opportunity to evolve landward and hence, are expected to disappear permanently.