Abstract
Coastal risks are increasing due to the warming of the climate,
resulting in rising mean sea levels and changes in storminess.
Projections of future coastal flooding rely on global climate models
based on greenhouse gas scenarios with inherent large uncertainties. The
past warm climate of the Last Interglacial (LIG,
~127,000 years ago) is considered a partial analogue of
a future warmer world. Therefore, understanding how coastal systems were
affected by changes in atmospheric and relative sea levels during the
LIG can inform us about possible future changes. In this contribution we
will analyze extreme sea levels and coastal flooding during the LIG. The
analysis is based on the hydrodynamic Global Tide and Surge Model (GTSM;
Muis et al., 2016, doi: 10.1038/ncomms11969). To simulate storm surges
during the LIG GTSM will be forced by 6-hourly wind and surface pressure
fields from LIG simulations of IPCC-type climate models. Due to
non-linear effects, tides and surge levels will be influenced by changes
in mean sea level. Therefore, a key input variable is map of regional
mean sea levels during LIG. However, there is still considerable
uncertainty on sea level high-stands and regional patterns during the
LIG. Using output from a Glacial Isostatic Adjustment model (GIA), we
will model tides and surges for a set of plausible scenarios of relative
sea levels and assess sensitivities.