Antarctic sea-ice in a changing planet - insights from palaeoclimate archives.

Sea ice is currently undergoing major changes. In the Arctic, sea ice has been declining rapidly over the last few decades, with an expectation of amplified global climate change due to ice-albedo feedbacks. Conversely, the total Antarctic sea ice cover has been steadily increasing since systematic satellite observations began in the late 1970s, although a precipitous decline since 2014 has halved the increasing trend for 1979-2018 relative to 1979-2014 [1]. Observations of both Antarctic and Arctic sea ice conditions are limited to the satellite era (post 1970). Thus, it is hard to assess the significance of recent trends. Climate model simulations of future warming are heavily dependent on the historical sea ice area data [2], and thus it is of global importance that we provide reliable paleo-sea ice reconstructions to ensure that the climate models tasked with predicting future changes are fully optimised.