Abrupt changes are developing across Antarctica’s ice, ocean and biological systems. These systems interact so that a change in one part can increase the risks of triggering abrupt change in other parts of Antarctica and the Southern Ocean.

For Australia, abrupt changes are expected to bring:

• Increased vulnerability to coastal infrastructure and communities due to accelerating sea level rise;
• Intensified global warming through reduced carbon dioxide removal by the Southern Ocean;
• Amplified regional warming due to Antarctic sea-ice loss; and
• Reduced rainfall over Southern Hemisphere continents from shifting weather patterns.

Existing efforts through the Antarctic Treaty System to reduce non-climatic pressures on Antarctica’s biological systems and establish protected areas are critical for building resilience, but to be effective they must be in addition to decisive policy action that mitigates global climate changes.

The only way to avoid further abrupt Antarctic changes and their impacts is to reduce CO2 emissions rapidly enough to limit global warming to as close to 1.5°C as possible.

Even with transformative emission reduction actions, plausible futures including multiple abrupt changes from Antarctica should be considered by governments, businesses and communities in their planning for future climate and sea-level rise impacts.

This policy briefing is based on a collaborative paper published in Nature that contributes to delivering the Australian Antarctic Science Decadal Strategy. It was led through the Australian Centre for Excellence in Antarctic Science, along with researchers from Securing Antarctica’s Environmental Future, the Australian Antarctic Program Partnership and the Australian Antarctic Division, as well as international collaborators.