The next 30–50 years are expected to be a crucial period for forecasting ice loss in Antarctica and preparing for potential sea level rise. A recent study published in Nature examines the reliability of predictions regarding Antarctic ice loss and their significance for planning climate adaptation measures.

Potential Consequences of Ice Loss

According to the Intergovernmental Panel on Climate Change (IPCC), under high emissions scenarios, global sea levels could rise by more than two meters by 2100 if significant portions of the Antarctic ice sheet collapse. Such a rise could flood a quarter of Australia’s homes, render vast areas of the Pacific region uninhabitable, and force hundreds of millions of people worldwide to leave their homes. This could become one of the largest humanitarian and economic disasters in history.

Uncertainty in Projections

Despite the scale of the threat, the trajectory of sea level rise by the end of the 21st century remains highly uncertain, primarily due to the difficulty in estimating the rate of ice loss in Antarctica. IPCC assessments suggest that, in the worst-case scenario, the rate of sea level rise caused solely by Antarctic ice could nearly double over the next 30 years. Until now, there have been no precise estimates of Antarctica’s contribution to sea level rise in the coming decades—a period that is especially important for government policy and coastal planning.

Key Research Questions

The study focuses on two main questions: how much ice could Antarctica lose in the next 30–50 years, and is it possible to predict these losses with enough confidence to allow timely preparation by governments and regions? To answer these questions, the researchers assessed the predictability of sea level rise using various ice sheet models over a relatively short time horizon.

Reliability of Short-Term Forecasts

The results show that Antarctic ice loss remains fairly predictable up to about the middle of the century. This allows existing models to provide reliable estimates of Antarctica’s contribution to sea level rise in the coming decades, which is vital for planning adaptation measures. If the models accurately reflect current rates of ice loss, they can be used to forecast changes over the next 30–50 years.

Long-Term Risks and Uncertainties

By the end of the 21st century, predictability decreases as the likelihood of physical processes that could rapidly accelerate ice loss increases. Some Antarctic ice lies below sea level, and if rapid retreat begins, this process could become difficult or even impossible to stop. In such a scenario, ice loss could far exceed short-term forecasts.

Implications for Climate Planning

The study highlights the importance of improving ice sheet models and monitoring systems to enhance the reliability of long-term forecasts. Over the next three decades, sea level rise trajectories are relatively well defined, making this period especially important for long-term adaptation planning and infrastructure development.

The Role of International Cooperation

Australia is well positioned to collaborate with partners in the Indo-Pacific region and can help translate scientific findings into practical adaptation strategies. Pacific island nations need reliable short-term forecasts to make decisions about infrastructure, community relocation, and long-term land use.

A Two-Stage Approach to Forecasting

Researchers believe that Antarctic forecasts are most useful when divided into two timeframes: short-term ice loss, which can be predicted with greater confidence, and long-term changes associated with feedback mechanisms that could sharply accelerate ice retreat. This approach provides a clearer basis for preparing for sea level rise, taking into account increasing uncertainty toward the end of the century.

About the SAEF Program

Securing Antarctica's Environmental Future (SAEF) is a research and education program led by Monash University and is part of the Australian Antarctic Program. SAEF conducts research in Antarctica and the Southern Ocean to support Australia, Asia-Pacific countries, and the global community in the face of ongoing climate change.