Antarctica’s future beyond 2100: high emissions would drive major long-term ice loss

The Antarctic ice sheet holds enough ice to raise global sea levels by nearly 60 meters if it were to melt completely. Yet, its long-term evolution under global warming remains uncertain. The new study, published in Nature Communications, systematically examines a wide range of factors, from regional climate changes to ocean-driven melting at the ice sheet’s base, to better understand how Antarctica’s ice might evolve in the coming centuries.

By combining advanced simulations with observational data, the researchers have narrowed the range of possible outcomes. Under very high and unmitigated emissions, the study finds that Antarctica will experience large-scale, self-sustaining ice loss. Beyond the very likely long-term retreat in East Antarctica, the authors deem the long-term collapse of the West Antarctic Ice Sheet to be “virtually certain” under such very high emissions. This would contribute between +0.7 and +6.0 meters to global sea level rise by 2300, permanently reshaping coastal communities and ecosystems worldwide. Conversely, limiting warming through rapid emission reductions and achieving net-zero greenhouse gas emissions well before 2100 could preserve much of East Antarctica’s ice and significantly reduce future sea-level rise. In this scenario, Antarctica’s contribution ranges from –0.1 to +1.7 meters by 2300.  However, even in this optimistic scenario, the West Antarctic Ice Sheet could still retreat substantially.

The study highlights that choices made in the coming decades will shape Antarctica’s ice and global coastlines for many centuries. It underlines the need to rapidly reduce emissions and strengthened adaptation efforts to limit long-term risks from sea-level rise. Ann Kristin Klose, PIK scientist and co-first author of the study concludes: "Reducing emissions is not just about stabilizing temperatures, it’s about protecting coastlines, communities, and the planet’s long-term stability.”