Even with the sea ice melting earlier and freezing later, the route remains fraught with perils for ships. The freezing of sea spray on the top of a ship, known as icing, can leave a vessel top-heavy and make it capsize. Growlers — icebergs sitting low in the water and difficult to spot — are notorious for sinking ships. Rocks and rogue waves are also a hazard.

Oil tankers like the Exxon Valdez often capture the public imagination and fear. But cargo ships pose a danger as well. In 2004 the Malaysian-flagged Selendang Ayu was grounded in a storm off the Aleutian Islands. Carrying 133 million pounds of soybeans, the ship broke in two, spilling more than 8,000 barrels of fuel oil.

“The U.S. Coast Guard didn’t even attempt a recovery of the oil because they had no facilities or personnel,” says Michael Byers, a legal scholar and an Arctic specialist at the University of British Columbia and the author of “Who Owns the Arctic?”

That was on the southern coast of Alaska. Handling a spill would be even more difficult farther north. At present, there is no technology able to separate oil from sea ice. If a spill occurred, ocean currents would likely push the oil or contaminants under the ice, where it would be impossible to track or remove.

“We can’t afford to have an oil spill in the Canadian Arctic,” Byers says. Trudeau recently formalized a moratorium on crude oil tanker traffic along the northern coast of British Columbia, but he has remained silent on the environmental risks of ships using the Northwest Passage.





The last few years of weakening ice in the passage have led to a number of commercial shipping firsts in quick succession. In 2013 the Nordic Orion crossed the Northwest Passage, assisted by an icebreaker — a first for a non-ice-strengthened bulk carrier. Traveling from Vancouver to Finland via the Arctic instead of the Panama Canal, it shortened the journey by four days and 1,000 nautical miles. Just a year later and unassisted by an icebreaker, the Nunavik carried mineral ore from Quebec to China through the vaunted passage.

There is no shipping boom — yet. Last year 14,000 ships passed through the Panama Canal, producing $2 billion in revenue for the Panamanian government. Only 50 transited the Northwest Passage.

But as the summer ice melt extends, commercial shipping through the North is becoming increasingly viable. “I’m certainly expecting that in the next 10 to 20 years, regular late summer, early fall shipping traffic will be considered normal in Canada’s Arctic,” says Byers.