In northern Norway, trees are rapidly taking over the tundra and threatening an ancient way of life that depends on snow and ice

Altafjord is a wide expanse of black water on the edge of the Barents Sea, ringed with mountains. Alta is a relatively large town in the Finnmark province, the crown of the horse’s mane that forms Norway’s jagged coastline and Europe’s northern shore. Here at sea level the most northerly trees in Europe are moving upslope, gobbling up the tundra as they go. The people and animals that live here are trying to make sense of the rapid changes with a mixture of confusion, denial and panic.

Dawn at 70 degrees north during winter lasts nearly the whole day. The sun never rises, the day is permanently on the verge of breaking. It is disorienting. On the way to city hall from the guesthouse, I spied few pedestrians. Alta is a town built along American principles – that is to say a town built for a world in which petrol is cheap and cars are taken for granted. It is a landscape of shopping malls, gas stations and spaced-out residential suburbs. Normally at this time of year it isn’t safe to be outside for long without wearing animal skins, but on the day of my visit it was only -1C.