Researchers using a 3-million-year climate simulation found that the Antarctic ice sheet reacts nonlinearly to carbon dioxide. Specifically, when CO2 levels drop below 236 ppm, the ice sheet undergoes rapid expansion due to a threshold response that stabilizes ice shelves against the seabed. This discovery highlights that climate systems do not always change gradually. Understanding these abrupt thresholds helps scientists improve the accuracy of future sea level rise projections as current atmospheric CO2 levels remain significantly higher than these historical tipping points.
