Only six years ago, the BBC reported that the Arctic would be ice-free in summer by 2013, citing a scientist in the US who claimed this was a ‘conservative’ forecast. Perhaps it was their confidence that led more than 20 yachts to try to sail the Northwest Passage from the Atlantic to the Pacific this summer. As of last week, all these vessels were stuck in the ice, some at the eastern end of the passage in Prince Regent Inlet, others further west at Cape Bathurst.

Shipping experts said the only way these vessels were likely to be freed was by the icebreakers of the Canadian coastguard. According to the official Canadian government website, the Northwest Passage has remained ice-bound and impassable all summer.

The BBC’s 2007 report quoted scientist Professor Wieslaw Maslowski, who based his views on super-computer models and the fact that ‘we use a high-resolution regional model for the Arctic Ocean and sea ice’.

He was confident his results were ‘much more realistic’ than other projections, which ‘underestimate the amount of heat delivered to the sea ice’. Also quoted was Cambridge University expert