The world may have warmed by around 1C (1.8F) over the past century but the Arctic far outstrips this global average and is warming at around twice the rate of the rest of the world.

In places, the rate of warming has been astonishing. Novembers in the Alaskan town of Utqiaġvik, formerly Barrow, are now 5.5C warmer than they were in 1979. In the summer of 2019, an Arctic heatwave saw parts of Greenland reach temperatures 40C hotter than normal.

The Arctic is dominated by sea ice, unlike the Antarctic which is essentially a huge land-based ice sheet. As the ocean and atmosphere warm, sea ice is shrinking in extent, at around 13% a decade since 1979, according to Nasa. The bright white surface of ice, known as albedo, is giving way to the dark ocean, meaning that sunlight is being absorbed rather than reflected, amplifying the warming effect.

These "rapid" and "unprecedented" changes are transforming the Arctic and threatening traditional ways of life, according to US government scientists in a 2019 report card. The sea ice is younger, thinner, more fragile and less extensive, making hunting on the ice harder and more perilous. The marine ecosystem is shifting as warmer water forces fish species to retreat to more northern waters.

What is a major challenge to communities in the Arctic, is a boon to the shipping industry, which can navigate the area more easily. This task will get even simpler once the Arctic is ice free in summertimes, forecast as soon as 2040s.