Interglacials are warm intervals in Earth's climatic history characterised by high global average temperatures, reduced ice sheet extent, and higher-than-present sea levels. Geological records from many sites around the globe allow the identification of several interglacials since the late Pliocene, each different in terms of height and duration of peak sea level and wave intensity. Studying these periods is particularly pertinent for unravelling sea level oscillations and wave regime variations and refining models of polar ice melting in the near future. Relative sea level (RSL) and wave conditions are reconstructed using geological and biological sea level proxies, which are formed in relation to the past position of the sea level. Although we comprehensively understand global sea level dynamics during the current interglacial (Holocene), our knowledge of these dynamics during past interglacials remains limited. Hence, a compendium of sea level and wave condition proxies over the multi-millennial scale of multiple interglacials will help assess sea level impacts in a future warmer world.

This special issue presents studies broadly related to sea level and coastal geological processes during the Pliocene and Pleistocene interglacials. The studies present new field data, re-analysis of previously published data with new techniques, and new models of coastal processes in the past, including hydrodynamics and geodynamics, as well as contributions to geochronology methods and remote sensing techniques applied to constrain sea level proxies in both active and steady tectonic settings.

Review process: all papers of this special issue underwent the regular interactive peer-review process of Climate of the Past handled by members of the editorial board as well as guest editors designated by the CP co-editors-in-chief.