A study reveals that warm ocean water intrusion into marine ice-sheet grounding zones can trigger a tipping point, leading to unbounded melting and accelerated ice loss. The research shows that as warm water intrudes beneath ice sheets, it increases melting, which in turn widens the grounding zone, further enhancing melting. This feedback mechanism can lead to runaway melting, with dramatic consequences for ice dynamics. The study highlights that current ice-sheet models may not fully capture this process, leading to underestimations of future sea-level rise. The findings suggest that both warm and cold water cavity ice shelves in Antarctica may be vulnerable to this process. The study also indicates that early warning indicators for such tipping points may be difficult to detect, as the transition to unbounded melting occurs gradually. The research emphasizes the importance of understanding the complex interactions between ocean water intrusion, melting, and ice geometry in predicting ice sheet behavior and sea-level rise. The study concludes that the tipping point is generic and can occur in any marine-terminating ice sheet exposed to sufficiently warm ocean water, with implications for the stability of ice shelves and the overall contribution of Antarctica and Greenland to sea-level rise.A study reveals that warm ocean water intrusion into marine ice-sheet grounding zones can trigger a tipping point, leading to unbounded melting and accelerated ice loss. The research shows that as warm water intrudes beneath ice sheets, it increases melting, which in turn widens the grounding zone, further enhancing melting. This feedback mechanism can lead to runaway melting, with dramatic consequences for ice dynamics. The study highlights that current ice-sheet models may not fully capture this process, leading to underestimations of future sea-level rise. The findings suggest that both warm and cold water cavity ice shelves in Antarctica may be vulnerable to this process. The study also indicates that early warning indicators for such tipping points may be difficult to detect, as the transition to unbounded melting occurs gradually. The research emphasizes the importance of understanding the complex interactions between ocean water intrusion, melting, and ice geometry in predicting ice sheet behavior and sea-level rise. The study concludes that the tipping point is generic and can occur in any marine-terminating ice sheet exposed to sufficiently warm ocean water, with implications for the stability of ice shelves and the overall contribution of Antarctica and Greenland to sea-level rise.