A new analysis shows that a “pause” in the Arctic winter sea ice decline registered in the 2020s has ended, after unprecedented losses in 2025 and in early 2026.
A study recently published in the journal PNAS, led by the University of Southampton (United Kingdom), shows that, despite the slowdown in the Arctic winter ice melt at the start of the decade, the “exceptionally reduced” amount of sea ice in the winters of last year and this year returns the region to a trend of significant decline.
“This pronounced decline alters the way we interpret the recent changes in Arctic winter sea ice,” notes climatologist Duo Chan, the study’s first author.
“What appeared to have been a pause in the early 2020s now seems to have been a temporary slowdown within the scope of a long-term decline associated with global warming,” he explains.
Researchers say that Arctic sea ice is an important indicator of climate change. Winter sea-ice cover acts as a barrier between the relatively warm Arctic Ocean and the much colder winter atmosphere.
Thus, less ice formed during the Arctic’s colder months allows more heat and moisture to emanate from the ocean into the atmosphere. This can affect pressure patterns, the development of storms, and large-scale atmospheric circulation, impacting climate much farther south.
Between 2024 and 2025, Arctic sea ice extent during the winter peak, between February and March, fell 5.8%. This was the largest annual decline in winter since satellite records began in 1978.
In 2026, the maximum sea ice extent at the peak phase recovered slightly but remained the second lowest on record.
To analyze the results more deeply, the team compared what was being observed by satellites with simulated events, using the latest climate-change models.
“By identifying these analogous events, we found that such a steep decline in 2025 was unusual, but physically plausible given the current warming of the Arctic,” says Alessandro Silvano, co-author of the paper.
Based on the models used, the scientists understand that it is more likely that Arctic sea ice will remain at low levels in the coming years and that it will not quickly recover to the levels seen at the start of the decade. And they make clear that the northernmost region of the planet continues to lose ice as the Earth warms.
