Within 50 years, ordinary ships will be able to negotiate shipping lanes through the Arctic Ocean during late summer, new UCLA research shows.

Based on independent climate forecasts for the years 2040 to 2059, the team’s found that in the Arctic ocean’s most navigable month, September, icebreakers won’t be needed as they are now.

“We’re talking about a future in which open-water vessels will, at least during some years, be able to navigate unescorted through the Arctic, which at the moment is inconceivable,” says PhD candidate Scott Stephenson.

Indeed, the Arctic ice sheet is expected to thin so much that polar icebreakers will be able to head from the Pacific to the Atlantic ocean by traveling straight across the North Pole.

“Nobody’s ever talked about shipping over the top of the North Pole,” says geography professor Laurence Smith. “This is an entirely unexpected possibility.”

The change could shorten the length of Arcic journeys by a fifth – the North Pole route is 20 percent shorter than today’s most-trafficked Arctic shipping lane, the Northern Sea Route, which hugs the coast of Russia. This has already been seeing more traffic, with 46 ships successfully using it last summer.

And the famous Northwest Passage, which follows Canada’s coastline and offers the most direct route from Asia to eastern Canada, could also become far more usable. Currently navigable only one year out of seven, the team believes that by mid-century it’ll be navigable every other year.

Choosing whether to ship through the passage “will become a coin toss,” says Smith.

Opening up these routes, though, could also open up a can of worms. While the US hasn’t so far ratified the United Nations Convention on the Law of the Sea, it could now have an incentive to do so. Ratifying the treaty could give the US sovereignty over some of these new shipping lanes, allowing ships to use them without paying the hefty escort fees currently demanded by Russia for similar routes.

On the other hand, the availability of new shipping routes could also bring the US into conflict with Canada, which has long claimed sovereignty over the Northwest Passage.