From October 2024 to September 2025, temperatures across the entire Arctic region were the hottest in 125 years of modern record keeping, the US National Oceanic and Atmospheric Administration (Noaa) said, with the last 10 years being the 10 warmest on record in the Arctic.

The Arctic is heating up as much as four times as quickly as the global average, due to the burning of fossil fuels, and this extra heat is warping the world’s refrigerator – a region that acts as a key climate regulator for the rest of the planet.

“There’s been a steady decline in sea ice and unfortunately we are seeing rain now even in winter,” said Druckenmiller. “We are seeing changes in the heart of winter, when we expect the Arctic to be cold. The whole concept of winter is being redefined in the Arctic.”

These changes are acutely felt by people and wildlife in the Arctic – rain falling on to snow can freeze into a barrier that makes it harder for animals to forage for food, while also making for more slippery, hazardous conditions for people traveling by road. The retreat of glaciers can also cause potentially dangerous flooding, as seen in Juneau, Alaska, this year.