- Satellite images show a massive chunk of sea ice in West Antarctica, roughly the size of Montana, has not refrozen after a winter heatwave, marking a dramatic change.
- Antarctic sea ice has entered a reduced state since 2015, with sea ice levels in West Antarctica about 50% lower than average this year.
- The lack of refreezing could contribute to global sea level rise, as the West Antarctica Ice Sheet collapse could raise sea levels by over 10 feet.
- June 2025 saw record-low sea ice levels in the region, with 12.6 million square kilometers of Antarctic sea ice, 1.3 million square kilometers below the 1991-2020 average.
- Contributing factors include strengthening westerly winds linked to climate change and a low-pressure anomaly causing warm air to prevent sea ice formation.
- The heat wave creates a feedback loop, as the lack of reflective white ice surface allows the area to stay warmer, further hindering refreezing.
- Glaciologists are closely monitoring the western Antarctic shelf, particularly Thwaites Glacier, which already contributes to 4% of global sea level rise and is accelerating in deterioration.