Over the next decades to centuries, will melting of the Antarctic Ice Sheet (AIS) – Earth’s largest ice mass – cause global sea level to rise by five metres, two metres or less? It’s a difficult question to answer. The Antarctic and Southern Ocean environment is dynamic and unpredictable. This means that there is uncertainty in our understanding of the behaviour of the AIS and what this means for future sea-level rise. Now scientists from Australia, the United States and Canada, have identified actions that will help reduce uncertainties about the future behaviour of the ice sheet and sea-level rise projections. Their work will also guide research to reduce the uncertainties faced by policymakers, decision-makers and communities needing to plan and adapt to a changing world. Scientists conduct research on the Antarctic Ice Sheet to better understand key processes and potential feedbacks that affect ice sheet retreat. Photo: Nick Morgan Sources of uncertainty The team of researchers, led by Australian Antarctic Division glaciologist Dr Ben Galton-Fenzi, reviewed research on the key processes and potential feedbacks that can accelerate AIS retreat. “We examined how Antarctica will contribute to sea-level change in the coming decades to centuries and where the uncertainties lie that make it difficult to project future behaviour of the ice sheet,” Dr Galton-Fenzi said. “Then we looked at what processes and regions should be the focus of future scientific research to reduce these uncertainties.” If the AIS were to completely melt, global sea levels would rise by about 58 metres. The huge East Antarctic Ice Sheet (covering two thirds of the continent) would contribute about 52 metres of this sea-level rise, while the West Antarctic Ice Sheet and the Antarctic Peninsula would make up the rest. In the simplest terms, the Antarctic Ice Sheet grows due to snowfall […]