Antarctica’s sea ice plunges as a three-stage cascade unlocks a new climate state

A Science Advances study identifies a three-stage cascade—strengthening circumpolar winds pushing warmer, saltier water to the surface, surface water becoming saltier and more buoyant, and feedbacks that prevent new ice formation—that has driven Antarctica’s sea ice to a multi‑year decline, with record lows in 2022 and 2023. East Antarctica and West Antarctica show different drivers (deep-ocean heat vs. atmospheric warming). The loss of sea ice exposes ice sheets to waves and warmer waters, reduces sunlight reflection, and could accelerate global warming; if the trend continues into the 2030s, the climatic and sea‑level implications could be substantial.