Quantifying the probability of committed AMOC collapse

Philip Bernard Holden, Jesse Abrams, Michelle Bieger, Timothy M. Lenton, Jean-Francois Mercure, Gregor Semieniuk, Simon Sharpe

The collapse of the Atlantic Meridional Overturning Circulation AMOC would have catastrophic consequences for societies. We quantify the risk of committed AMOC collapse using large ensembles of Earth system model simulations. Under conservative assumptions of Greenland ice sheet melt, the probability that collapse is already committed is 10%, rising to 80% by 2100 under worst case emissions. Under less conservative Greenland melt assumptions, probability that collapse is already committed is 23%.