A record low at the winter peak
Arctic sea ice has reached its lowest winter maximum on record, scientists reported this week. The ice cover stopped growing in March at a smaller size than any winter since satellites began tracking it in 1979.
This year's peak was about 1.4 million square kilometers below the average for recent decades. The missing ice is roughly the size of Alaska.
Researchers at the National Snow and Ice Data Center called the result consistent with a long-term trend. Winter ice has shrunk steadily for more than 40 years.
Heat pushes the system past old limits
The low ice year follows months of record warmth. Global oceans recorded their hottest July on record, and air temperatures over the Arctic ran far above normal through the winter.
Warm water is the main driver. Ocean heat stored during summer is released slowly in winter, slowing the growth of new ice. Strong winds can also push ice away from the coast and break it up.
Scientists say an El Niño pattern developing in the Pacific is adding heat to the system. That could make the coming summer melt season especially harsh. The pattern matches the warming trend seen across the entire Arctic region in recent years.
Why shrinking ice matters
Sea ice loss does more than change the map. Open water absorbs more sunlight than bright ice, so the Arctic warms faster as ice disappears. This feedback loop speeds up warming across the planet.
Wildlife is also affected. Polar bears, walruses, and seals depend on ice for hunting and resting. Coastal communities face stronger waves and erosion as the protective ice shelf thins.
Scientists warn that the Arctic could see ice-free summers within the next few decades. This year's record is another marker on that path. Researchers will publish a full analysis of this year's melt season in the autumn.