Arctic Ocean shipping routes 'to open for months'
University of Reading, UK, researchers have investigated how the decline in sea-ice, driven by warmer temperatures, will make the region more accessible.
They find that by 2050, opportunities to transit the Arctic will double for non ice-strengthened vessels.
These open-water ships will even be going right over the top at times.
And if CO2 emissions are not curtailed - if the aspirations of the Paris Agreement to keep global temperature rise "well below two degrees" are not implemented - then moderately ice-strengthened vessels could be routinely ploughing across the Arctic by late century for perhaps 10-12 months of the year.
"The reduction in summer sea-ice, perhaps the most striking sign of climate change, may also provide economic opportunities," commented Reading's Dr Nathanael Melia.
"There is renewed interest in trans-Arctic shipping because of potentially reduced costs and journey times between Asia and the Atlantic. So far only a few commercial vessels have utilised these routes as they are not currently reliably open."
Sea-ice is in a committed, long-term decline as the polar north warms.
The traditional September minimum extent is about to be set in the coming days, and this year looks on course to be the second lowest in the satellite record.
Researchers do not see this trend being reversed anytime soon.
"If we experience a 2-degree increase in global temperatures, we will get close to an Arctic that is effectively ice-free for part of the year; that's less than a million sq km of ice cover," said Reading's Dr Ed Hawkins.
"So, even if future emissions are consistent with the Paris agreement, it will of course mean shipping routes will be more open. Not every year, but more regularly than they are now."
"Open water vessels won't be hugging the Russian coast quite so much, and ice-strengthened ships will be going right over the pole," he told BBC News.
The incentives are clear: if vessels can transit the Arctic, they will shave many days off their journey times between the Pacific and North Atlantic ports, and save fuel.
In addition, by plotting a more central course, they can avoid the fees they would otherwise be charged for going through Siberian waters.
The team has been looking at how the opportunities might evolve in the decades ahead.
The group used five prominent climate computer models and essentially trained them to better reflect the distribution of Arctic sea-ice as seen in current observations.
They then ran those models forward through the century under different emissions scenarios, to gauge where and how frequently shipping routes would become navigable.