The Point of No Return: New Evidence Shows Antarctic Melting Is Already Locked In

Scientists drilling 500 feet through Antarctic ice retrieved a 23-million-year sediment core showing West Antarctica's ice sheets melted rapidly during past warm periods similar to today's climate. The core, collected by the international SWAIS2C project led by geoscientist Johann Klages of Germany's Alfred Wegener Institute, demonstrates that human-caused warming has already triggered irreversible long-term melting that could raise sea levels 3 feet by 2100 and submerge southern Florida within two to three centuries. New modeling studies show melting in one Antarctic basin can destabilize neighboring regions in a cascading process, potentially locking in thousands of years of continued sea-level rise even if temperatures stabilize. Binghamton University associate professor Molly Patterson, co-chief scientist of the mission, said detailed geochemical analyses of the sediment layers—which show past ice advances, retreats, and open-water periods—could take years to complete. The findings underscore that the critical window to prevent catastrophic ice-sheet collapse is the next few decades, when feedback processes may push the system past irreversible thresholds.