As climate change progresses, the Arctic Ocean gets closer to becoming ice free during warmer months. Scientists expect new shipping routes to open up, creating new possibilities for transport and trade between the North Atlantic and the North Pacific. However, different climate models give different predictions for when and where new routes will emerge.
Here Stephenson and Smith suggest these differences should be embraced, at least for now. They worked out near-future Arctic shipping possibilities for 10 different global climate models. Collectively, the models predict greater Arctic shipping access. Separately, they reveal a more nuanced collection of possibilities.
The scientists chose to study Coupled Model Intercomparison Project Phase 5 models that have successfully predicted recent observations of Arctic sea ice and weather. They fed two different climate change scenarios into the models, one with lower radiative forcing and one with higher radiative forcing. Each model predicted monthly mean sea ice concentration and thickness north of 45°N for two periods: 2011–2035 and 2036–2060.
The scientists used the ice predictions to calculate which shipping routes would give the lowest travel time from Rotterdam, Netherlands, and Halifax, Nova Scotia, to the Bering Strait. They considered routes for both open-water vessels and Polar Class 6 vessels—ice-strengthened ships that can sail through medium-thick ice in warmer months.
Together, the models show that east Arctic paths—such as the Northern Sea Route (NSR)—will remain the most reliable, as they already are today. However, most of the models predict that shorter central routes cutting close to the North Pole will open up briefly each year by 2060, potentially diverting traffic from the NSR. For all models, the use of Polar Class 6 ships improves trans-Arctic accessibility much more than high radiative forcing.
Separately, the models predict very different routes and show variability in terms of when each will become accessible: Some models predict certain routes will open for just 1 month out of the year, whereas other models show the same routes open for 6 months. Accessibility of the Northwest Passage, which passes through the Canadian Arctic Archipelago, was particularly dependent on the specific model being considered.
New Arctic shipping routes will ultimately depend on more than just geophysical changes; economic and regulatory factors are also in play. Nonetheless, better understanding of the climate’s effects on potential shipping routes will help governments, environmental agencies, and the maritime industry plan for the future of the Arctic. (Earth’s Future, doi:10.1002/2015EF000317, 2015)
—Sarah Stanley, Freelance Writer
Citation: Stanley, S. (2016), Climate models predict diverse Arctic Ocean shipping routes, Eos, 97, doi:10.1029/2016EO044567. Published on 27 January 2016.