The WARMCOASTS project worked towards advancing the understanding of coastal and sea-level dynamics during the Last Interglacial (LIG) through an integrated programme of fieldwork, data compilation, and modelling across five Work Packages. The project achieved its overarching goals through three key objectives.
Objective 1 aimed to better constrain peak global mean sea level during the LIG. This was achieved through WP1, WP2 and WP3. In WP1, the main result was the creation of the World Atlas of Last Interglacial Shorelines (WALIS) — a standardized global database that was developed via a coordinated international collaboration. WALIS now serves as an open-access global reference for LIG palaeo–sea-level research. In WP2 and WP3 geological surveys were carried out in several study areas. In combination with geophysical modelling, this body of work revealed that peak sea level likely remained below 5 m, significantly lower than previously estimated. In WP3, novel work on dynamic topography, sediment isostasy, and the newly formulated concept of reef isostasy was carried out, further advancing our knowledge on LIG sea-level changes.
Objective 2 explored short-term sea-level oscillations within the LIG. IN WP4, different kinds of stratigraphic forward models (Dionisos Flow and REEF) were used to simulate reef growth under variable sea-level histories, comparing modelled with observed reefs. This work demonstrated that these models can reproduce observed reef systems, and showed that multi-stepped or backstepped reef morphologies could arise from either rapid oscillations, or reef dynamics alone. Complementary modelling of tidal notches and field data from the Caribbean, Indian Ocean, and Mediterranean provided new insights into the tempo of sea-level change, showing that intra-interglacial fluctuations may have occurred more rapidly than previously recognised.
Objective 3 focused on locating and quantifying proxies of extreme waves. This objective was pursued mainly in WP5, using innovative approaches integrating field geology, hydrodynamic and climate modelling, and remote sensing. Field campaigns in Argentina and Cape Verde showed the potential of beach and boulder ridges to investigate paleo wave processes at local scale. A pioneering study also modelled sea-level extremes globally under LIG and pre-industrial climates, showing that warmer orbital conditions amplified storm surges and coastal flooding potential.
Across all WPs, the project introduced novel interdisciplinary and open-science practices, including freely available databases, code repositories, and visualization tools hosted on Zenodo, GitHub, and FigShare. Knowledge transfer was reinforced through the training of early-career scientists, one Ph.D. completion, and multiple master’s theses.
Dissemination and exploitation of the results were extensive: WALIS and related datasets have collectively exceeded 80,000 views and downloads; over 30 peer-reviewed papers were published or submitted; and outreach activities through media and social platforms expanded the visibility of ERC-funded science. Together, these outcomes establish a durable scientific and infrastructural legacy that continues to shape global research on sea-level change and coastal dynamics.
