A sweeping review in the journal Nature warns that Antarctica has entered a phase of rapid, self-reinforcing change that could push parts of the global climate system past irreversible tipping points. The 21-author study, led by Nerilie Abram of the Australian National University and the Australian Antarctic Division, synthesises field observations, ice cores and historical ship logs to show that the continent’s sea-ice, ice sheets, ocean currents and ecosystems are now changing in lock-step. Satellite records reveal that since 2014 Antarctic sea-ice has retreated about 120 kilometres from the shoreline—three times faster than the rate of loss in the Arctic over a much longer period. The shrinking ice cover exposes darker ocean water that absorbs more solar energy, warming the region further and accelerating a marked slowdown in the Antarctic Overturning Circulation, a deep-ocean current that helps regulate global climate and nutrient flows. The authors warn that continued warming could trigger the “unstoppable collapse” of the West Antarctic Ice Sheet, adding at least three metres to global sea levels, while a total melt of the continent would raise oceans by around 58 metres. Wildlife is already suffering: entire emperor penguin colonies have lost chicks after early sea-ice breakup, and krill and phytoplankton populations are declining as surface waters warm and acidify. Abram’s team concludes that existing conservation rules under the Antarctic Treaty cannot stem these physical changes. The study says only rapid, steep cuts to greenhouse-gas emissions that keep global warming as close as possible to 1.5 °C can reduce the risk of further abrupt shifts with “catastrophic consequences for generations.”