Overview

• An international overview in Nature warns the West Antarctic Ice Sheet may be at or near a tipping threshold, with a full collapse raising global sea level by more than three meters over centuries to millennia.
• Researchers describe reinforcing feedbacks linking sea‑ice loss, accelerating ice‑sheet retreat and a slowdown of the Antarctic Overturning Circulation, amplifying regional warming and long‑term sea‑level rise.
• Evidence of weakening deep circulation suggests the Southern Ocean could absorb less CO2 while redistributing heat, oxygen and nutrients in ways that affect global marine systems.
• Ecological impacts are mounting, with about 30 of roughly 60 emperor penguin colonies suffering repeated partial or total breeding failures since 2016, raising extinction concerns by 2100 if trends persist.
• A separate Nature Sustainability study finds heavy‑metal‑laden fine particulates in visited areas roughly ten times higher than 40 years ago, tied to tourism growth from about 20,000 to 120,000 annual visits, and authors urge rapid, deep CO2 cuts this decade.