As the Arctic sea ice thins and retreats, new shipping routes are being evaluated as possible alternatives to the Suez or Panama canals for trade between the North Atlantic and the North Pacific. On paper, these Arctic routes are 35 to 60 percent shorter, but studies using climate models to predict their opening produce different outcomes for when – or whether – these new routes will emerge.
Scott Stephenson, a geographer at the University of Connecticut, in Storrs, studies the changing environment and economy of the Arctic. More specifically, Stephenson is interested in understanding how climate change impacts the physical environment of the Arctic and how this creates new opportunities and challenges for communities – both inside and outside the Arctic – to participate in the global economy.
In a new paper published in the journal Earth’s Future, Stephenson and his colleague Laurence C. Smith, from the University of California, Los Angeles, used 10 climate models, known to reasonably predict Arctic sea ice and weather, to examine Arctic shipping routes during two time periods, from the recent past to the near future and beyond: 2011-2035 and 2036-2060.
Stephenson talks with Arctic Deeply about the possibility of a new trans-polar route opening up in the future, and how economic and regulatory factors, including icebreaker infrastructure and commodity prices, will continue to influence the economic viability of Arctic routes.
Arctic Deeply: Why you set out to do this study on Arctic Sea Routes?
Scott Stephenson: In the past, there had been a lot of analysis of the changing Arctic sea ice, and then a lot of discussion about what that could mean for future Arctic access, but there hadn’t been, to my knowledge, an attempt to put the two together, to bring the scientific modelling together with this more applied question of where might you be able to go at different times over the course of the century. It was that gap in the literature that initially got me interested in this.
Arctic Deeply: According to the models that you used, how will a warmer world change accessibility to the Northern Sea Route?
Scott Stephenson: It was robustly clear that the Northern Sea Route became accessible sooner in the models than the Northwest Passage. The Northern Sea Route becomes accessible soonest and with the greatest amount of area being made ice free, at least compared to other places in the Arctic.
Arctic Deeply: And how is that different from what you see elsewhere, for the Northwest Passage, for example?
Scott Stephenson: The big differences were for the Northwest Passage and also the trans-Arctic, or you might call it the transpolar route. The transpolar route became more accessible, more quickly in some models than others. In general, across the models there was a gradual movement or migration of the so-called least-cost optimal routes away from the Northern Sea Route towards the more efficacious, shorter transpolar route. That happens faster in some models than others. I don’t think anyone is thinking seriously about using the transpolar route any time soon, but as a vision for the Arctic of several decades from now, it is rather compelling.
There were a couple of models that illustrated very clear accessibility through the Northwest Passage, which is not something that we expected. They’re well-respected models and they generally do a good job of reproducing the observed dynamic seasonality and sea ice extent in the Arctic as a whole, but those that observe the Arctic do not expect that to happen.
Nonetheless, there are these important regional differences, and so pointing those out and pointing out the implications for policy, if you were to make planning decisions, for example, based on the results of this model versus [the other] one, you could come to very different conclusions.
Arctic Deeply: What exactly do the results suggest about Arctic shipping in future? Does it mean it will be easier or less risky?
Scott Stephenson: It will become generally easier in some areas, but of course the devil is in the details. I think along Russia’s coast, it’s likely to become easier and easier, as the navigation season lengthens. The Northern Sea Route is the part of the Arctic that currently has the best icebreaker infrastructural coverage, even though it is not nearly as high as elsewhere in the world. But in other areas it is likely to become paradoxically more dangerous, more risky.
There are a number of studies that look at how climate change and melting ice will actually increase the likelihood of encountering very thick and hard multiyear ice in the Northwest Passage, where otherwise it wouldn’t have been, as a result of the ice chunks getting broken up in the central Arctic and then imported into the archipelago.
Arctic Deeply: What other non-climatic factors influence the viability of Arctic Sea routes?
Scott Stephenson: I would put priority on the non-climatic factors as actually having an impact on driving Arctic traffic. Our paper looked specifically at possibilities, potential physical access. But when you’re talking about, for example, economic trends, such as the price of oil, the price of certain commodities and the availability of ice-strengthened ships or other infrastructure that could support Arctic operations – I mean these are the things that are really driving or conversely constraining Arctic shipping now, and most likely in the future.
Much of the shipping that takes place in the Arctic is of bulk resources rather than the container shipping that makes the global economy go around. If the prices of those commodities fall significantly, you won’t see as much of it being shipped around. The Arctic will seem like less of a prospect because you won’t be making that much money to begin with. Why risk a risky passage that is only open for a brief period of the summer time and for which you would need a contract for an ice-strengthened vessel or an ice breaker to support it?
Arctic Deeply: Models can help us understand what may happen in the future, but there are limitations to their accuracy. What are some of the factors that influence whether the outputs are likely to be correct?
Scott Stephenson: That’s a difficult question to answer, because I don’t consider myself to be a modeller, although I am generally familiar with how they work. There is very lively scientific literature out there that attempts to quantify the skill of the various models, not just Arctic models, but any climate models, to determine which models perform the best. The general consensus about this right now is that it is very difficult if not impossible to come up with a definitive ranking, because various models do very well in some areas and not so well in others. There are inherent regional biases, some models reproduce dynamics in the Canadian Arctic really well, but do poorly in the American or Russian Arctic. And so, depending on what you decide is important, or what factors do you weight highly in your ranking, you get different results.
But one of the conclusions that we came to in our paper, and has been said by others as well, in non-Arctic context, is that you really need to look at a wide range of models, not because you are trying to determine which one is the best, but because looking at the whole suite of models gives you a general idea of the range of the variability that is out there.
So you might be able to say, “OK, based on the results of all of these models, we might expect a slim chance of there being no ice next summer and a greater chance of there being some ice and a slim chance of there being so much ice that we can’t go anywhere,” or something along those lines. It gives you a probability density distribution of what you are likely to be seeing, and that is really why I think models are most useful. By showing results from a number of different models in this study, we were basically trying to give others a sense of the range of variability and the uncertainty in the projections in the Arctic shipping context.
Arctic Deeply: I often hear that we need more and better observations in the Arctic, whether that is from polar orbiting satellites or buoys that measure temperature, etc. Would that help improve the accuracy of these models?
Scott Stephenson: Absolutely. Models are being constantly updated and tinkered with, and every time we get a new observed dataset, whether it is from in situ measurements or from satellites, they are always being used to help us tune the next generation of models. And there is an informal competition going on around the world, lots of different modelling groups have their own model and try to make improvements to it. The more data we collect, the closer we will be able to converge on an accurate representation of how our physical world really works.
Arctic Deeply: What’s the take away for governments and the maritime industry?
Scott Stephenson: I think that government and industry really need to understand the limitations of climate models and understand that no single model has the power to definitively predict the future.
When making policy or when creating a strategic plan – whether that’s a government creating a strategic plan or a company creating a strategic plan for its business operations – it needs to take into account that there is a lot about the climate and about sea ice that we don’t know and we can’t predict, and that only by looking at results from a lot of different models will we get some sense of the true variation, the true variability that’s out there.
This interview has been edited for clarity and length.
Top image: Warming over the next several decades is expected to open up new shipping routes in the Arctic. (USGS/Patrick Kelley)