Norwegian explorer Erling Kagge: 'The Arctic is heating up in every way'

In Perspective, we spoke to the Norwegian explorer Erling Kagge, the first man to reach the North Pole unassisted by animals or vehicles. He is also the first person ever to reach the North and South Poles and the summit of Mount Everest on foot. His book "The North Pole: The History of an Obsession" has just come out in French translation.