Projected coastal flood impacts in France by 2050 using CMIP6 climate projections

Climate change is expected to significantly affect insurers’ liabilities through an increase in claims associated with more frequent and intense meteorological hazards. These include both extreme events such as tropical cyclones and storms, and more recurrent phenomena such as floods and droughts. In this context, the mutual insurance group Covéa conducts climate-impact studies in collaboration with the specialized climate-risk Hydroclimat company.

The study focuses on the projected evolution of coastal flooding risk in France by 2050. According to the HANZE database (Paprotny D., 2024), between 1950 and 2020, approximately one-third of flood events in France involved a coastal flooding component. Major historical events, such as Storm Xynthia in 2010 and the October 1987 storm, resulted in insured losses of €660 million and €1.5 billion (CCR, 2023), highlighting the significant financial exposure associated with coastal hazards.

To anticipate future impacts, Hydroclimat produced coastal flood-extent maps based on CMIP6 climate projections, integrating existing coastal protection systems within a hydro-geomorphological modelling framework. Exposure and vulnerability analyses were conducted using Covéa’s national residential building database. These results provide an initial assessment of the projected increase in the number of exposed residential buildings and the associated insured losses by mid-century.

This work contributes to a better understanding of future coastal flood risk under climate change and supports insurers in adapting risk assessment and portfolio management strategies to evolving coastal hazards.

References

Paprotny, D. (2024) - HANZE catalogue of modelled and historical floods in Europe, 1950–2020 (v1.2) https://doi.org/10.5281/zenodo.12635205

Caisse Centrale de Réassurance (2023) – Risque de submersion sur la côte atlantique : l’analyse CCR – https://www.ccr.fr/submersion-marine-cote-atlantique-scenario-ccr/ [last access : 2025/12/15]