Warming opens famed waterway through Arctic

Beneath the aurora borealis, an oil tanker glides through the night past the Coast Guard ice breaker Amundsen and vanishes into the maze of shoals and straits of the Northwest Passage, navigating waters that for millennia were frozen over this time of year.

Warming has forced a retreat of the polar ice cap, opening up a sea route through the Canadian Arctic archipelago and connecting the Atlantic and Pacific Oceans for several months of the year.

Commander Alain Lacerte is at the helm as the vessel navigates the Queen Maud Gulf, poring over charts that date from the 1950s and making course corrections with the help of GPS.