Abstract

For any external attendees, please email Birgit Rogalla (birgal at bas.ac.uk) and Yohei Takano (yokano at bas.ac.uk) to arrange for access to BAS .

In this talk I will present a framework for developing storylines of UK sea-level rise to aid risk communication and coastal adaptation planning. The approach builds on UKCP18 and maintains the same physically consistent methods that preserve component correlations and traceability between global mean sea level (GMSL) and local relative sea level (RSL). Five example storylines are presented that represent singular trajectories of future sea-level rise drawn from the underlying large Monte Carlo simulations. The first three storylines span the total range of the IPCC AR6 likely range GMSL projections across the SSP1 -2.6 and SSP5 -8.5 emissions scenarios. The final two storylines are based upon recent high-end storylines of GMSL presented in AR6 and the recent literature. Our results suggest that even the most optimistic sea-level rise outcomes for the UK will require adaptation of up to 1 m of sea-level rise for large sections of coastline by 2300. For the storyline most consistent with current international greenhouse gas emissions pledges and a moderate sea level rise response, UK capital cities will experience between about 1 and 2 m of sea-level rise by 2300, with continued rise beyond 2300. The storyline based on the upper end of the AR6 likely range sea-level projections yields much larger values for UK capital cities that range between about 3 and 4 m at 2300. The two high-end scenarios, which are based on a recent study that showed accelerated sea-level rise associated with ice sheet instability feedbacks, lead to sea-level rise for UK capital cities at 2300 that range between about 8 m and 17 m. These magnitudes of rise would pose enormous challenges for UK coastal communities and are likely to be beyond the limits of adaptation at some locations.