Climate change impacts on coastal flooding around the UK and Ireland

Coastal floods are amongst the most dangerous natural hazards globally. This also applies to the UK where flooding is one of the highest priority risks for civil emergency (Cabinet Office, 2015) and to Ireland, where coastal flooding was identified as the top sectoral priority for marine climate services (Fitzhenry and Nolan, 2023). Recent floods (e.g. winters of 2013/14, 2019/20 and 2022/23) have demonstrated the ever-present threat of serious flood impacts in coastal regions, despite improved flood-protection measures and technology that has provided tools to forecast and mitigate risks. While flood-defence standards in the UK and Ireland are among the highest in the world, significant populations and assets in the coastal flood plain are threatened in the event of defence failure during events exceeding the standard of protection (e.g. major overtopping or a breach). Annual average economic damages from coastal flooding in the UK are around £540 million currently (Sayers et al., 2015). Furthermore, coastal flooding is a growing threat due to accelerating mean sea level rise and possible changes in tides and storminess associated with climate change (Palmer et al., 2018; Fox-Kemper et al., 2021). There is also a continued decline in natural habitats that act as natural coastal protection, such as saltmarshes and sandy shorelines (e.g., Masselink et al., 2016, 2022; Burden et al., 2020). Impacts of coastal flooding are projected to increase in the future with population growth, urbanisation, continued development in low-lying coastal areas (Stevens et al., 2016) and habitat degradation (Bednar-Friedl et al., 2022).