DECADAL COASTLINE RESPONSE TO ACCELERATED SEA LEVEL RISE

During most of the 20th century, the global mean sea level (GMSL) has been rising at around 1.8 mm/yr. However, since the early 90s, this rate has increased to beyond 3 mm/yr, and over 2006 – 2018 the rate of rise is 3.7 mm/yr [3.2 – 4.2 mm/yr] (Fox-Kemper et al., 2021). While it appears that the world’s coastlines have remained more or less resilient against the slow sea level rise (SLR) over the 20th century (Stive, 2004), it is almost a certainty that they will respond to the much higher rates of GMSLR (upto ~ 12mm/yr by end of 21st century) projected for the future (Fox-Kemper et al., 2021). In this study, we analyse available long-term beach and dune datasets to investigate detectable trends in coastline indicators, especially since the early 90s when GMSLR rates of over 3 mm/yr have been observed. Here, we subject data from several sites in the US, Europe, Australia and Japan to a detailed analysis, focusing on coastline indicators such as the shoreline, dune crest etc.