Sea ice surrounding Antarctica is on the brink of hitting a winter low record for the second year in a row, marking a significant decline in the freezing of the Southern Ocean. Last year, the Antarctic region experienced an unexpected transformation as the sea ice covering the continent plummeted continuously for six months. During winter, it was observed that the sea ice covered approximately 1.6 million square kilometers less than the long-term average, an area roughly equivalent to the combined size of Britain, France, Germany, and Spain.

According to the scientists from the Australian Antarctic Program Partnership, this alarming trend has continued this year as well. On September 7th, data revealed that the frozen ocean was even less than on the same date last year. Although the final record for the winter season is yet to be complete, this data is part of a growing body of evidence indicating that the Antarctic system has transitioned into a "new state."

Dr. Will Hobbs, a sea ice researcher at the University of Tasmania, described these two events as extremely significant. He stated, "Last year's decline was outrageous, and it seems to be happening again." Hobbs highlighted that the primary driver of regional variability on both monthly and yearly timescales is the atmosphere. However, what distinguishes the current situation is the impact of warmer temperatures in the Southern Ocean on the sea ice. The past two years have been recognized as the warmest on record, with global temperatures surpassing pre-industrial levels by more than 1.5 degrees Celsius for extended periods. Consequently, this global warming is now evident in the oceans surrounding Antarctica.

Recent data shows that the Southern Ocean sea ice covered approximately 17 million square kilometers on Saturday, slightly lower than last year's previous low of 17.1 million square kilometers. The long-term average, based on satellite information for September 7th, is approximately 18.4 million square kilometers.

Dr. Phil Reid from the Australian Bureau of Meteorology cautioned that it is too early to definitively state whether the winter sea ice has reached its maximum level. Nevertheless, he expressed concern about the sea ice consistently plunging far below average in consecutive years. While the full impact of decreased sea ice levels on weather and climate is still being studied, recent research suggests that it contributes to an increase in summertime rain events and dry winter days in Australia. Reid stated that the loss of sea ice in the Antarctic leads to ocean and atmospheric interactions, which ultimately drive these changes.

Dr. Hobbs warned that it may take decades for Antarctic sea ice to recover from the events of last year, and by then, the long-term consequences of global heating will be evident. He emphasized that the return to the long-term average sea ice cover is becoming increasingly unlikely.

While the loss of sea ice does not directly result in a rise in global sea levels, scientists emphasize that it does have an indirect impact, particularly in the summer. The reduction in sea ice removes a protective barrier, accelerating the loss of glacial ice from the continent and contributing to ocean warming as the exposed dark waters absorb more heat from the atmosphere.

Notably, a study conducted by scientists from the British Antarctic Survey found that the significant decrease in Antarctic sea ice observed in late 2022 potentially led to the death of thousands of emperor penguin chicks. Moreover, a study published in Nature last year revealed that if greenhouse gas emissions continue at their current level, the meltwater from the Antarctic ice sheets could substantially slow down the Southern Ocean's overturning circulation, a critical deep ocean current, by 2050. Another study estimated that this circulation, which impacts global weather patterns, ocean temperatures, and nutrient levels, has already slowed by approximately 30% since the 1990s.

The ongoing decline in sea ice around Antarctica raises concerns about the long-term impacts on the continent's ecosystems, weather patterns, and global climate. Urgent action is needed to address the underlying causes of global warming and its effect on the fragile ecosystem of Antarctica.