In 2023, Antarctic sea ice reached record lows, an event that researchers say only happens once every 2,000 years. The British Antarctic Survey used data from the CMIP6 climate dataset to study this dramatic loss of sea ice. The winter ice coverage dropped by more than 2 million square kilometers in 2023.
This is an area about ten times the size of the United Kingdom. What makes this even more surprising is that sea ice had been growing steadily until 2015. Lead author Rachel Diamond said that climate change made the low sea ice levels more likely.
But the models showed that an event this big would still be very rare, even with climate change. “This is the first time this large set of climate models has been used to determine how unlikely 2023’s low sea ice actually was,” Diamond explained. The researchers also looked at the long-term effects of this sea ice loss.
Co-author Louise Sime noted that even after twenty years, the sea ice around Antarctica does not fully recover. “The impacts of Antarctic sea ice staying low for over twenty years would be profound,” Sime said.
Antarctic ice’s unprecedented plunge
It would affect weather patterns and ecosystems, including whales and penguins. This study shows how important it is to understand rapid sea-ice losses and their lasting effects. The researchers said their findings are significant for predicting future sea ice conditions in the coming decades.
Satellite records of Antarctic sea ice began in 1978. The sea ice extent increased slightly until 2015. But 2017 saw a record low, and sea ice has been relatively low for several years since then.
Antarctic sea ice plays a crucial role in the overall climate. It influences ocean currents and weather patterns. It also protects ice shelves from waves, which helps limit Antarctica’s contribution to sea level rise.
Sea ice is also vital for marine life. Low sea ice in recent years has caused breeding failures in emperor penguin colonies. The study, titled “CMIP6 Models Rarely Simulate Antarctic Winter Sea-Ice Anomalies as Large as Observed in 2023,” was published in the journal Geophysical Research Letters on May 20, 2024.
