Implications of ambiguity in Antarctic ice sheet dynamics for future coastal erosion estimates: a probabilistic assessment

Sea-level rise (SLR) can amplify the episodic erosion from storms and drive chronic

erosion on sandy shorelines, threatening many coastal communities. One of the major

uncertainties in SLR projections is the potential rapid disintegration of large fractions of

the Antarctic ice sheet (AIS). Quantifying this uncertainty is essential to support sound

risk management of coastal areas, although it is neglected in many erosion impact

assessments. Here, we use the island of Sint Maarten as a case study to evaluate the

impact of AIS uncertainty for future coastal recession. We estimate SLR-induced coastal

recession using a probabilistic framework and compare and contrast three cases of AIS

dynamics within the range of plausible futures. Results indicate that projections of coastal

recession are sensitive to local morphological factors and assumptions made on how AIS

dynamics are incorporated into SLR projections and that underestimating the potential

rapid mass loss from the AIS can lead to ill-informed coastal adaptation decisions.