Interglacials are warm intervals in Earth's climatic history characterized 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 that have occurred since the late Pliocene, each different in 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. The 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 in assessing sea-level impacts in a future warmer world.

This special issue invites the international sea-level community to present studies broadly related to sea level and coastal geological processes during the Plio-Pleistocene interglacials. We welcome studies presenting new field data and re-analysis of previously published data with new techniques and new models of coastal processes in the past including hydrodynamics and geodynamics. We also welcome contributions to geochronology methods and remote sensing techniques applied to constrain sea-level proxies in both active and steady tectonic settings.

The climate history since the Last Interglacial (~ 130 000 years ago) is marked by profound transitions, ranging from abrupt events to gradual reorganizations of the Earth system. This period offers a unique testing ground for evaluating and refining Earth system models across a wide spectrum of boundary conditions, from glacial extremes to interglacial warmth.

Simulating the climate dynamics of the last glacial cycle – including transitions, feedbacks, and tipping elements – enables us to assess the structural robustness of Earth system models used for future projections. Such model–data comparisons are critical not only to constrain uncertainties, but also to understand possible regime shifts in climate variability, the emergence of nonlinear behaviour, and the relevance of long-term feedbacks under anthropogenic forcing.

The climate history since the Last Interglacial (~ 130 000 years ago) is marked by profound transitions, ranging from abrupt events to gradual reorganizations of the Earth system. This period offers a unique testing ground for evaluating and refining Earth system models across a wide spectrum of boundary conditions, from glacial extremes to interglacial warmth.

Simulating the climate dynamics of the last glacial cycle – including transitions, feedbacks, and tipping elements – enables us to assess the structural robustness of Earth system models used for future projections. Such model–data comparisons are critical not only to constrain uncertainties, but also to understand possible regime shifts in climate variability, the emergence of nonlinear behaviour, and the relevance of long-term feedbacks under anthropogenic forcing.

Interglacials are warm intervals in Earth's climatic history characterized 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 that have occurred since the late Pliocene, each different in 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. The 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 in assessing sea-level impacts in a future warmer world.

This special issue invites the international sea-level community to present studies broadly related to sea level and coastal geological processes during the Plio-Pleistocene interglacials. We welcome studies presenting new field data and re-analysis of previously published data with new techniques and new models of coastal processes in the past including hydrodynamics and geodynamics. We also welcome contributions to geochronology methods and remote sensing techniques applied to constrain sea-level proxies in both active and steady tectonic settings.