Understanding extreme sea levels for broad-scale coastal impact and adaptation analysis

• Published in: Nature communications 2017-07, Vol.8 (1), p.16075-16075, Article 16075
• Main Authors: Wahl, T., Haigh, I. D., Nicholls, R. J., Arns, A., Dangendorf, S., Hinkel, J., Slangen, A. B. A.
• Format: Article
• Language: English
• Subjects: 639/166/986; 704/4111; 704/829/2737; 704/844/2739; Adaptation; Coastal environments; Human settlements; Humanities and Social Sciences; Impact analysis; multidisciplinary; Regional analysis; Science; Science (multidisciplinary); Sea level; Sea level rise
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms16075

One of the main consequences of mean sea level rise (SLR) on human settlements is an increase in flood risk due to an increase in the intensity and frequency of extreme sea levels (ESL). While substantial research efforts are directed towards quantifying projections and uncertainties of future global and regional SLR, corresponding uncertainties in contemporary ESL have not been assessed and projections are limited. Here we quantify, for the first time at global scale, the uncertainties in present-day ESL estimates, which have by default been ignored in broad-scale sea-level rise impact assessments to date. ESL uncertainties exceed those from global SLR projections and, assuming that we meet the Paris agreement goals, the projected SLR itself by the end of the century in many regions. Both uncertainties in SLR projections and ESL estimates need to be understood and combined to fully assess potential impacts and adaptation needs. Uncertainties in contemporary extreme sea levels (ESL) from mean sea level rise (SLR) projections have been overlooked in broad-scale risk and adaptation studies. Here, the authors quantify the uncertainties in present-day global ESL estimates and find that they exceed those from global SLR projections.