Emergent climate change signals within Antarctic sea ice and associated ecosystems

Antarctic sea ice is projected to decline with continued global climate change, potentially impacting Antarctic ecosystems on several levels. Here using a series of models, we show that substantial regional and seasonal differences exist in when and how climate change patterns manifest in Antarctic sea ice, phytoplankton, krill, fish and penguins. Climate-driven changes in fish and penguins tend to emerge from historic variability earlier than sea ice and lower trophic levels. Changes are highly seasonal and can be either negative or positive; for example, krill growth increases in the spring, but decreases in the summer in many regions. The earliest climate signals emerge in Eastern Antarctic regions, while the Ross Sea remains a refuge from climate change into the twenty-first century. In the coming decades, summer sea ice loss in the Weddell Sea could improve the region for fish and krill growth, while remaining habitable for Emperor penguins.