Study Warns 0.25°C Ocean Warming Could Trigger 4-Metre West Antarctic Ice Collapse
Updated
Updated · spacedaily.com · Jun 20
Study Warns 0.25°C Ocean Warming Could Trigger 4-Metre West Antarctic Ice Collapse
3 articles · Updated · spacedaily.com · Jun 20
Summary
A June 2025 modelling study found the West Antarctic Ice Sheet could enter irreversible collapse once nearby deep-ocean temperatures rise 0 to 0.25°C above current levels, ultimately adding about four metres to global sea levels.
The trigger in the model is marine ice sheet instability: warm water thins buttressing ice shelves, the grounding line retreats into deeper water, and that retreat then sustains itself even without further warming.
The paper does not say the threshold has already been crossed, but it notes the Amundsen Sea is warming and points to Thwaites and Pine Island glaciers as the most immediate areas of concern.
Researchers based the analysis on simulations spanning 800,000 years, yet the result remains one modelling study rather than a consensus, with other recent work differing on how close the ice sheet is to a tipping point.
The study highlights a sharp timing mismatch—destabilisation could be triggered within decades, while the resulting sea-level rise would unfold over centuries to millennia and outlast normal infrastructure planning horizons.
If West Antarctica's collapse is now unavoidable, how will the world manage centuries of unstoppable sea-level rise?
Is 2026's record loss of Antarctic sea ice the definitive trigger for the ice sheet's irreversible collapse?
Can mega-scale engineering projects physically halt the irreversible collapse of the West Antarctic Ice Sheet?
The 0.25°C Tipping Point: Imminent Risk of Irreversible West Antarctic Ice Sheet Collapse and Global Sea-Level Rise
Overview
Recent scientific findings from 2025 and 2026 reveal that the West Antarctic Ice Sheet (WAIS) is at a critical tipping point, with just a 0.25°C rise in deep ocean temperatures around West Antarctica potentially triggering its irreversible collapse. This vulnerability is driven by warm deep ocean water eroding the ice sheet’s base, especially in the Amundsen Sea region. Scientists are now closely monitoring ocean temperatures to see how quickly this threshold is being approached. The potential collapse of the WAIS poses a global catastrophic risk, highlighting the urgent need for immediate action to reduce emissions and prevent severe consequences.