Southampton Study Identifies 3-Stage Driver of Antarctic Sea Ice Collapse Since 2015
Updated
Updated · Oceanographic Magazine · May 18
Southampton Study Identifies 3-Stage Driver of Antarctic Sea Ice Collapse Since 2015
3 articles · Updated · Oceanographic Magazine · May 18
A University of Southampton-led study says Antarctic sea ice losses since 2015 followed a three-stage shift that culminated in record lows in 2023 and may now be self-sustaining.
Around 2013, stronger winds lifted warm, salty deep water upward; by 2015, intensified mixing pushed that heat into surface layers, erasing sea ice over an area comparable to Greenland.
Since 2018, reduced ice has left surface waters warmer and saltier, suppressing new ice formation and trapping the Southern Ocean in a reinforcing low-ice state.
The study found East Antarctica's retreat was driven mainly by ocean heat from below, while West Antarctica lost ice during 2016 and 2019 summers as cloud cover and subtropical air trapped ocean heat.
Researchers warn that if low sea-ice cover persists into 2030 and beyond, the Southern Ocean could shift from buffering climate change to accelerating global warming, ocean-current disruption and sea-level rise.
Antarctica is now accelerating global warming. Is this tipping point irreversible and what happens to the world next?
Climate models failed to predict Antarctica's rapid melt. How can we trust any forecasts for our planet’s future?
A hidden ocean process is melting Antarctica from below. What other climate time bombs are we missing?
Antarctic Sea Ice Hits Record Low in 2023: Causes, Consequences, and the Threat of a New Climate Regime
Overview
In 2023, Antarctic sea ice reached a record low winter maximum, signaling a dramatic shift in the region’s climate. This decline is closely linked to human-driven climate change, mainly caused by greenhouse gas emissions that have altered the planet’s energy balance. As a result, the Southern Ocean has absorbed most of the excess heat, leading to warmer subsurface waters that melt sea ice from below. These changes are not just temporary fluctuations but may represent a new normal, with cascading impacts on ecosystems, ocean circulation, and global climate stability.