Antarctic Sea Ice Hits Record Low as Concerns of Decline Grow
As winter comes to a close, the National Snow and Ice Data Center (NSIDC) reported that sea ice levels around Antarctica have reached a record low. This significant drop has raised concerns that Antarctic sea ice may be entering a state of decline due to climate change.
The NSIDC released an announcement on Monday expressing worry about a potential long-term trend of decline for Antarctic sea ice. The warming of oceans globally, along with the mixing of warm water in the Southern Ocean polar layer, could contribute to this decline.
Sea ice around the polar regions undergoes seasonal growth and melting. In Antarctica, sea ice typically reaches its minimum coverage at the end of the Southern Hemisphere’s summer in February, and its maximum extent at the end of winter in September. However, scientists reported that Antarctic floating sea ice hit an all-time low at the end of this summer, and sea ice growth remained slow throughout winter.
On September 10, Antarctica reached its annual maximum coverage about 13 days earlier than average. At that time, the annual ice coverage was a record low of 6.55 million square miles, which is 398,000 square miles lower than the previous record set in 1986.
Twila Moon, an ice scientist at the NSIDC, described the low sea ice extent as “surprisingly low.” She noted that there has been no recovery towards previous higher extents during the Antarctic fall and winter, indicating a year-round influence.
The decline in sea ice around the polar regions poses a threat to adjacent ice sheets. Less sea ice means less sunlight is reflected back into space, causing water to warm and destabilizing surrounding ice and glaciers. Additionally, coastlines become more exposed, removing a buffer that could protect melting ice shelves or ice sheets.
While the downward trend in sea ice has been observed in the Arctic, it has been less clear in Antarctica. However, scientists now believe that Antarctica is reaching a turning point similar to the Arctic. In just seven years, the continent has experienced three new record-breaking low sea ice summers, suggesting that the underlying processes controlling Antarctic sea ice coverage may have changed.
Moon stated that the loss of sea ice in Antarctica is influenced by warming ocean temperatures and potentially other processes. This indicates a shift in the system, affecting Antarctic sea ice in all seasons.
Antarctica has been exhibiting responses to climate change in various ways. The continent, along with the Arctic, is warming faster than the global average. Warmer ocean temperatures surrounding Antarctica have caused significant ice melt, including the destabilization of the Thwaites Glacier, which contributes to 4% of annual global sea level rise. Changes in ocean movements and atmospheric patterns have also become more apparent.
Gail Whiteman, an expert on global risks resulting from polar climate change and professor of sustainability at the University of Exeter, emphasized the importance of polar ice as a significant insurance policy against runaway climate change. The concerning decline in sea ice in both the Arctic and Antarctic raises alarm bells and suggests that urgent action is needed to address climate change.