September Sea Ice Update – Another Year in the New Arctic Normal 

This week marked the annual Arctic sea ice minimum, with 4.60 million square kilometres reached on September 10^th according to the National Snow and Ice Data Centre.  

This 2025 minimum is tied as the 10^th lowest extent since satellite records began in the late 1970s and is 15% lower than the minimum recorded in any year prior to 2007. The last 19 years have represented the lowest 19 sea ice extents in the satellite record. 

However, the real story isn’t about rankings anymore. It’s about the fundamental shift in how the Arctic operates. The Arctic Ocean has lost 95 percent of its oldest and thickest ice, and this year’s melt season started with a historically low winter maximum in March. As a result, at the beginning of September the pack is one of the thinnest and youngest on record. 

• Arctic sea ice minimum extent has halved since satellite records began in the late 1970s 

• This year’s minimum is 15% below the 1991-2020 average and shares the spot for 10th lowest on record with 2008 and 2010. 

• New research has shown natural climate cycles that once helped ice recover are now simply slowing the rate of loss rather than enabling genuine recovery (England et al. 2025) 

• Sea ice now freezes later and melts earlier, giving polar bears and other ice-dependent species less time to hunt and breed 

• Over 70% of Arctic sea ice is now thin seasonal ice, this is much more fragile and vulnerable to break up by storms compared to the thick, multi-year ice that once dominated 

Cascading Impacts on Arctic Wildlife 

Sea ice is freezing later in autumn and melting earlier in spring, creating a survival crisis for ice-dependent species. Polar bears now have less time to hunt seals, leading to declining body fat, falling populations, and lower cub survival rates. Pregnant females struggle to build the fat reserves needed for denning, while mothers produce smaller, weaker cubs. Bears are spending more time on land, turning to bird eggs, caribou carcasses, and even garbage as traditional food sources disappear. 

Walruses face their own crisis as the ice they once relied on to rest during feeding and migration disappears. With an increasingly ice free Arctic ocean they must swim further between feeding and resting sites, exhausting calves and adults alike. In autumn, tens of thousands crowd onto beaches in massive haul-out sites where they were once spread across stable ice floes. This overcrowding makes them vulnerable to predators, deadly stampedes and heat stress. 

What This Means For You

The loss of the Arctic’s ancient ice affects far more than polar bears and walrus. This thin, fragile ice can no longer regulate Earth’s climate as it once did. Less ice means less sunlight reflected back to space, accelerating global warming. The disappearance of thick, stable ice platforms disrupts ocean circulation patterns that influence weather systems worldwide—from European heatwaves to monsoon patterns in Asia. September’s ice loss is already programming next year’s extreme weather patterns, as a weakened Arctic can no longer buffer global climate systems. 

These challenges are coming at a time of unprecedented uncertainty for climate science. US-led cuts to critical environmental monitoring, including the satellite used to monitor the polar ice caps, have caused a scramble to switch to alternative systems. This September sea ice update has relied on data from the Japanese Aerospace Exploration Agency. Unplanned technical changes like this risk calibration issues between instruments that could impact our ability to understand the downstream consequences of a changing Arctic. 

As traditional knowledge holders observe, the ice now “feels different”. That difference is rippling across the entire planet. 

What happens in the Arctic doesn’t stay in the Arctic. 

Read more: NSIDC announcement | On Sea Ice – Global Climate Risk Platform 

Reference: 

England, M. R.,  Polvani, L. M.,  Screen, J., &  Chan, A. C. (2025).  Minimal Arctic sea ice loss in the last 20 years, consistent with internal climate variability. Geophysical Research Letters,  52, e2025GL116175. https://doi.org/10.1029/2025GL116175