Antarctica's waters are getting saltier and driving a collapse in its sea ice — and scientists aren't sure why.
Antarctic sea ice has been declining since 2015, defying model predictions to hit a record 0.6 million square miles (1.55 million square kilometres) below its expected average extent in 2023. At winter's peak in July of that year, the region was missing a chunk of ice bigger than Western Europe, and it's showing no signs of recovery.
