Emerging evidence of abrupt changes in the Antarctic environment

Abrupt changes are developing across Antarctica’s ice, ocean and biological systems. Antarctic systems interact so that a change in one part can increase the risks of triggering abrupt changes in other parts of Antarctica and the Southern Ocean. The rapid loss of Antarctic sea ice and slowdown of the Antarctic Overturning Circulation show some signs of being more susceptible to tipping point behaviour than equivalent changes in the Arctic and North Atlantic. There are imminent risks of triggering irreversible loss of the West Antarctic Ice Sheet and extinction of iconic Antarctic species including emperor penguins, and new processes of abrupt change, such as wave-driven collapse of ice shelves, are beginning to emerge. The only assured way to avoid further abrupt changes in the Antarctic environment is to make rapid and deep CO2 emission reductions, consistent with the climate mitigation goals of international climate agreements. Governments, businesses and communities can strengthen their climate resilience by considering plausible futures that include multiple abrupt changes from Antarctica in their scenario planning for future climate and sea-level rise impact