We are heading towards a climate state that has not been observed through human-made measurements before, making information on past climatic states increasingly important for anticipating future Earth System changes. Presently, sea ice is rapidly declining, and it plays a crucial role in the climate system, with proxy evidence suggesting its involvement in abrupt climate shifts.

In this session, we invite studies of past climates that aim to advance the understanding of sea ice processes and associated climate changes, thereby enhancing or constraining cutting-edge climate models. We are particularly interested in studies focusing on interglacials and warm periods, as well as other periods of climatic interest. Contributions that explore both colder and warmer-than-modern climate states are particularly encouraged.

We welcome:
-Studies that refine existing records or generate new time series from ice, terrestrial, and marine cores, including sea ice proxies such as IP25 or IPSO25 in marine cores, and Bromine, Iodine, MSA, water isotopes, and sea salt sodium from ice cores.
-Investigations into sea ice as both a driver and responder to high-frequency climate variability, with data from both polar oceans exploring Antarctic and Arctic sea ice extent alongside co-recorded climate feedbacks.
-Proxy evidence of past sea ice spatial and temporal changes.
-Both proxy and model studies that link past sea ice changes with other climatic processes, such as temperature changes, moisture source variations, or major ocean state changes like AMOC.

This session aims to bring together research on past sea ice dynamics during both colder and warmer-than-modern climate states, enhancing our understanding of sea ice processes and their role in climate systems. By refining existing records and generating new data, we seek to improve climate models and our ability to predict future changes. Join us in contributing to this critical area of research at EGU2025.