This year, winter sea ice cover in the Arctic reached its lowest-ever annual peak on March 22, 2025, according to National Aeronautics and Space Administration and the National Snow and Ice Data Center (NSIDC). The peak was the lowest recorded since satellite measurements began in 1979, 47 years ago. At 14.33 million square kilometres, the maximum extent fell below the previous record low of 14.41 million square kilometres set in 2017.
After its seasonal growth through autumn and winter, Arctic sea ice appears to have reached its annual maximum extent in 2025. This year’s maximum is a staggering 1.32 million square kilometres below the 1981–2010 average of 15.65 million square kilometres. To put this into perspective, the missing ice covers an area larger than the state of California. This continues a long-term downward trend that scientists have observed over the past several decades.
Adding to concerns, around the same time, Antarctic sea ice reached its annual minimum extent on March 1, measuring 1.98 million square kilometres — tied for the second-lowest minimum ever recorded. The combination of this record-low Arctic maximum and a near-record-low Antarctic minimum resulted in a record low for total global sea ice coverage in February 2025.
The record-low Arctic winter peak is particularly significant as it sets the stage for the summer melt season. With less new ice forming and less multi-year ice accumulating—continuing a trend seen in recent years—there is less ice to withstand the warmer months. Scientists believe that a warming climate is the primary driver behind this decline, with the Arctic warming about four times faster than the global average.
“This new record low is yet another indicator of how Arctic sea ice has fundamentally changed from earlier decades. But even more importantly than the record low is that this year adds yet another data point to the continuing long-term loss of Arctic sea ice in all seasons,” Walt Meier, Senior Research Scientist, National Snow and Ice Data Center.
The reduction in Arctic sea ice has far-reaching global consequences. Sea ice plays a crucial role in regulating Earth’s climate by reflecting sunlight and heat back into space. With less sea ice, more heat is absorbed by the ocean, contributing to climate disruptions and potentially altering weather patterns while threatening marine ecosystems.
Moreover, longer open-water periods in the Arctic, a direct consequence of reduced sea ice, could make the Arctic Jet Stream more erratic, leading to prolonged storms, extreme rainfall, and cold snaps across the Northern Hemisphere. These changes could have severe repercussions for agriculture, infrastructure, economic stability, and human livelihoods.
Sea ice is also fundamental to the Arctic food web, forming the foundation upon which many species depend. Algae grow within the ice, providing food for tiny organisms like zooplankton, which in turn sustain Arctic cod. Seals prey on the cod, and polar bears rely on seals for survival. The shrinking ice cover threatens biodiversity at multiple trophic levels, with the potential for significant population declines and even species extinctions.
The unprecedented loss of ice reinforces the urgent need to address human-caused climate change to mitigate its detrimental impacts on the Arctic and beyond. Additionally, the retreating ice is fueling geopolitical tensions, as nations compete for access to potential oil and gas resources in the Arctic. Countries with Arctic coastlines — including Russia, Canada, the United States, Norway, and Denmark (via Greenland) — are actively staking claims to the Arctic seabed, raising both environmental and political concerns.