A study published in Nature Climate Change has come to the conclusion that the future melting of the West Antarctic Ice Sheet (WAIS) in the 21st century is unavoidable even if greenhouse gas emissions were to be strongly reduced. The study looked at a range of different scenarios of future ice shelf melting in the Amundsen Sea, ranging from optimistic to pessimistic projections of emissions reductions during the rest of the 21st century. The study found that the warming of the Amundsen Sea is taking place at approximately triple the historical rate and that atmospheric climate variations in Antarctica would not have a large effect on the melting of the ice. The implication of this finding is that even under the most ambitious targets of the Paris Agreement, there is little that can be done to stop the decline of the WAIS). The WAIS is Antarctica’s largest contributor to sea level rise, and the ice sheet contains enough water to result in a 3 metre global sea level rise, with far reaching implications for coastal cities.
The study is the most comprehensive future projection of Amundsen Sea ice shelf melting so far. It was not possible for the researchers to work with direct observations, as data collection only commenced in 1994, and long-term observations of temperature changes and changes in ice mass changes are needed to confidently project future changes. Instead, the team analysed the outcomes of a model which predicted the behaviour of sea ice and ice shelf cavities using five different scenarios and working with a climate model that has been previously tested and validated for previous century and 21st century climate simulations. All five scenarios were found to predict significant future warming of the Amundsen Sea and therefore the increased melting of its ice shelves.