It was dark and cold when I spoke to Eric Brossier yesterday, but that’s normal. The 37-year-old French geophysicist and his girlfriend, France, are spending their fourth winter on board their 47ft yacht Vagabond in the Arctic in temperatures as low as -35 or -40°C. They are conducting part of an EU research project into climate change.

Everything has to be done in the perpetual night. There won’t be light in the north of Svalbard, Norway, until February. Yesterday, Eric was working on a weather mast. He was approached by a polar bear, but it was too dark to fire safely over its head to scare it off.

Although Vagabond is sheltered in a bay, rough seas can break up the ice, so outside Eric wears a survival suit, and sometimes has to swim part of the 100m to shore. This is a life of ultimate self-sufficiency. Everything they need, including 500kg of food for their three husky dogs, has had to be carefully stored. Other scientists will arrive in late winter, but for now it’s just them.