Arctic winter sea ice has reached a record low for a second year, with thinning ice and long-term decline highlighting escalating climate risks for ecosystems, wildlife and northern communities.
The Arctic’s winter sea ice extent has dropped to its lowest level on record for a second consecutive year, underscoring a persistent long-term decline driven by a rapidly warming region, according to new data from NASA and the National Snow and Ice Data Center.
Measurements show that Arctic sea ice covered 14.29 million square kilometres on March 15, 2026, narrowly below the 14.31 million square kilometres recorded in 2025. Satellite observations of sea ice extent date back to 1979.
Sea ice extent refers to the total ocean area with at least 15 percent ice concentration. It typically reaches its annual maximum during winter before melting through the summer. Some ice usually survives the melt season and accumulates over time, but scientists say that process has weakened in recent years as Arctic temperatures rise.
The 2026 winter peak was about 1.3 million square kilometres below the average recorded between 1981 and 2010, reflecting a steady downward trend observed over decades.
Researchers also reported notable thinning of Arctic ice. Data from NASA’s ICESat-2 satellite indicates that much of the ice this year is thinner, particularly in the Barents Sea northeast of Greenland.
“Based on what we’re seeing with NASA’s ICESat-2 satellite, much of the ice in the Arctic is thinner this year, especially in the Barents Sea northeast of Greenland,” said Nathan Kurtz, chief of the Cryospheric Sciences Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
He added that the Sea of Okhotsk, bordering northern Japan and Russia, also experienced relatively low ice levels this year, a region known for strong year-to-year variability.
“A low year or two don’t necessarily mean much by themselves,” said Walt Meier of NSIDC. However, he said that when viewed alongside the long-term decline since 1979, the recent records reinforce evidence of ongoing changes across all seasons.
Sea ice plays a critical role in Arctic and Antarctic ecosystems. Species such as walrus and seals depend on it for resting and giving birth, while polar bears use it for hunting and breeding. Other animals including Arctic fox, whales and caribou rely on it as foraging grounds, according to NSIDC.
Shrinking ice poses growing risks to these species. When sea ice retreats beyond the continental shelf, walruses must swim long distances, sometimes up to 402 kilometres round trip, to reach feeding areas or gather in large numbers on land.
Such crowding can prove deadly. Large haulouts of mostly female walruses and calves were first recorded in 2007 when summer sea ice reached its second-lowest level. In 2014, around 35,000 walruses gathered along a small beach in Point Lay, Alaska.
Scientists warn that these gatherings are highly vulnerable to disturbance. Sudden noise or the presence of predators can trigger stampedes. In one such incident in 2017 at Cape Schmidt in Russia, about 500 walruses died.
Beyond wildlife, Arctic communities depend on sea ice for fishing and traditional livelihoods. Its continued loss threatens not only ecosystems but also cultural identity in the region
