The Independent: Open water now stretches all the way round the Arctic, making it possible for the first time in human history to circumnavigate the North Pole. New satellite images, taken only two days ago, show that melting ice last week opened up both the fabled North-west and North-east passages, in the most important geographical landmark to date to signal the unexpectedly rapid progress of global warming.

Last night Professor Mark Serreze, a sea ice specialist at the official US National Snow and Ice Data Center (NSIDC), hailed the publication of the images – on an obscure website by scientists at the University of Bremen, Germany – as "a historic event", and said that it provided further evidence that the Arctic icecap may now have entered a "death spiral". Some scientists predict that it could vanish altogether in summer within five years, a process that would, in itself, greatly accelerate.