Torbjorn Tornqvist, Donald Cahoon, John Day, James Morris

Schuerch et al. (2018) [1] deserve credit for compiling a wide range of disparate, global datasets that will be instrumental in predicting future coastal wetland change. However, we challenge their projections that range from modest losses to substantial gains worldwide by the end of this century. Their modeling does not adequately capture the role of sediment supply which must be treated volumetrically, with profound implications for their projections. We anticipate that an appropriate modification will result in substantially different projections, with rates of coastal wetland loss that generally increase as a function of relative sea-level rise (RSLR), regardless of the human adaptation scenario. This is also in line with the findings from a precursor study [2] by a subset of the Schuerch et al. group.