Today's emissions choices could limit Antarctic ice loss and sea-level rise for coastal communities

Today's choices regarding greenhouse gas emissions could significantly impact Antarctic ice loss and sea-level rise, which will affect coastal communities, according to a new study published in Nature Geoscience. The research, led by an international team of scientists including Rutgers climate scientist Robert Kopp, reveals that reducing emissions now could limit the extent of ice loss by the end of the century compared to a scenario with very high emissions.

The study found an 89% probability that meeting the most ambitious low-emission goal of the Paris Agreement would result in less Antarctic ice loss by 2100 than a high-emission scenario. However, even with aggressive emission cuts, Antarctica is expected to lose ice overall, as it holds the world's largest store of frozen freshwater.

The ice sheet rests on land and, when it melts and flows into the ocean, raises sea levels. The study highlights that warmer ocean water melts ice shelves from below, thinning them, which can lead to faster glacier flow and increased ice loss. The researchers also found that warmer ocean water can weaken the ice shelves' ability to act as a brake on the glaciers, potentially accelerating the movement of ice into the ocean.

To address these uncertainties, the team employed machine learning to analyze existing simulations of ice-sheet behavior, allowing for rapid exploration of different assumptions and reducing the computational cost. The analysis identified major sources of uncertainty, such as how warming ocean water melts ice shelves, how ice slides over bedrock, and how the ocean and atmosphere warm around Antarctica.

While the study cannot account for all possible interactions among ice, ocean, and atmosphere, it emphasizes the importance of better measurements of these processes to refine projections and help communities make informed decisions about coastal development and protection.