High-latitude ocean and cryosphere during warmer than present climates of the Neogene and Quaternary: a view from Antarctic and NW Greenland (I)ODP expeditions

In the past four decades, high latitude regions have been warming 2 to 4 times more rapidly than the global average, and their ocean and cryosphere are rapidly changing. Arctic sea-ice loss, complex Antarctic sea-ice variability, instability of the Greenland and Antarctica continental icesheets, and melting have consequence for the entire planet including sea-level rise, changing ocean currents, and impacts on polar species, ecosystems and biodiversity. The International Ocean Discovery Program (IODP) completed 8 expeditions in high latitude locations during the past ~10 years. One aim that these expeditions share is to study ocean and cryosphere responses to warm climates in the geological past to get insights into cryosphere instability thresholds in a (future) warm climate scenario. Obtaining continuous high latitude records is challenging, but even snapshot views of the past offer important insights into the interaction among climate, ocean and cryosphere (in)stability, and ecosystem responses.

On behalf of numerous collaborators, I will present an overview of what we have learned so far about ocean and cryosphere variability during warm periods of the Neogene (Miocene Climatic Optimum and Pliocene) and the Quaternary. I will discuss (preliminary) results, mostly centered on palynology, obtained from Expeditions 374 (Ross Sea) and 400 (NW Greenland) in the context of additional sedimentological and geochemical data, and link them to results from previous (I)ODP expeditions and on-going projects.