Antarctica Sea Ice Reaches Alarming Low for Third Year in a Row

Sea ice coverage around Antarctica has dropped below 2m sq km for three years in a row, indicating an 'abrupt critical transition'.


Sea Ice Coverage at Record Low

According to the latest data from the US National Snow and Ice Data Center, sea ice coverage around Antarctica has reached a record low for the third consecutive year. The extent of ice floating around the continent has contracted to below 2m sq km, a threshold that had not been breached since satellite measurements began in 1979. This alarming trend suggests that Antarctica's sea ice has undergone an 'abrupt critical transition'.

Scientists are viewing this new record low as further evidence of a 'regime shift'. The continent's sea ice has become increasingly unstable, and the past three years have been the three lowest on record. These findings highlight the urgency of addressing the underlying causes of this decline and taking appropriate measures to mitigate its impact.

Antarctica experiences its lowest sea ice extent during the height of summer in February each year. On 18 February, the five-day average of sea ice cover fell to 1.99m sq km, followed by another decrease to 1.98m sq km on 21 February. The previous record low was set in February 2023 at 1.78m sq km.

Thinner Ice and Climate Change

Scientists are still investigating the reasons behind the declining sea ice coverage in Antarctica. While there are no reliable measurements of ice thickness, climate scientists specializing in Antarctica and the Southern Ocean suggest that the regrown ice may be thinner than usual. Thinner sea ice is more prone to melting, contributing to the decreasing sea ice extent.

Global heating is also a concern, as it warms the Southern Ocean surrounding the continent. Sea ice plays a crucial role in reflecting solar radiation, and its reduction can lead to more rapid ocean warming. This warming can have far-reaching consequences for ecosystems and wildlife that depend on the sea ice, such as phytoplankton and penguins.

Walt Meier, a senior research scientist at the National Snow and Ice Data Center, explains that much of the sea ice in Antarctica melts completely each summer. Consequently, the ice tends to be relatively thin, ranging from 1-2 meters thick. The low maximum extent observed in September indicates thinner ice in many areas, but the exact impact on the melting rate and minimum extent is yet to be determined.

The Urgency of Addressing Antarctic Changes

Scientists have been calling for governments to prioritize the changes occurring in Antarctica, as these changes can have global consequences. The loss of sea ice not only affects local ecosystems but also accelerates the loss of land ice, leading to rising global sea levels.

To better understand and address these changes, sustained measurements of ocean temperature and salinity underneath the sea ice are crucial. Improvements in climate models and increased data collection are necessary to develop effective strategies for mitigating the impact of declining sea ice in Antarctica. Scientists emphasize the need for urgent action and support in order to navigate this critical environmental shift.