Rapid and unprecedented changes to the global ocean will have serious impacts on the sustainability and management of many marine and coastal ecosystems. This Report Card provides an update on the latest developments in understanding the potential biological tipping points for the biota that comprise Southern Ocean ecosystems, highlighting the ACE CRC’s recent activities and niche in this expanding research area. It considers the potential broader ecological impacts of these changes under future climate change scenarios; and identifies key challenges and areas for further research.