Study Identifies Mechanisms Behind Antarctic Sea Ice Decline Since 2015

A new study published in the journal Science Advances has identified the mechanisms behind the collapse of Antarctic sea ice, which unfolded in three stages over the past decade after 2015. The study was led by researchers at the University of Southampton.

It found that around 2013, strengthening winds started drawing warm, salty circumpolar deep water closer to the surface beneath Antarctic sea ice.

Powerful winds then churned heat upward, triggering rapid sea ice melting in East Antarctica. Since 2018, the region has been trapped in a feedback loop where less sea ice leaves the ocean surface warmer and saltier, making new ice formation harder. The sea ice losses wiped out an area nearly the size of Greenland.

In East Antarctica, the sea ice decline is largely due to warm water rising from the deep. In West Antarctica, warm air from the subtropics and persistent cloud cover trapped heat near the ocean surface, contributing to major melting events during the summers of 2016 and 2019.

Antarctic sea ice reflects as much as 80 per cent of sunlight back into space. When it disappears, the darker ocean absorbs more heat and accelerates warming. From 2002 to 2020, Antarctica lost roughly 149 billion metric tons of ice each year.

Scientists estimate that every centimetre of sea level rise exposes around six million people to coastal flooding. Warmer ocean waters can also erode ice both on land and at sea, increasing the risk of ice shelves collapsing. “This isn't just a regional problem,” said Alessandro Silvano.

Tourism to the continent has grown sharply even as instability increases. Around 122,000 people visited Antarctica in 2024, up from approximately 44,000 in 2017. Researchers from the University of Tasmania estimate visitor numbers could eclipse 450,000 annually by 2033.

Euronews reported on the study and its implications for the Southern Ocean and global climate systems.