For centuries, significant resources have been expended in search of the Northwest Passage, or as Pierre Berton once called it; the “Arctic Grail.” Franklin, Davis, Ray, Baffin, Amendment, Blot, Monk, and Perry are just a few of the names that have gone down in history for their quest for the shortest route from Europe to Asia. It was sea ice that foiled the best laid routes and provided the suspense and intrigue we are all now familiar with. The waxing and waning of sea ice movement in the northern hemisphere has long created seasons when a ship could sail easily through Baffin Bay, while in other years “rivers” of ice flushed down from the Lincoln Sea towards the Labrador coast. The high variability experienced by these explorers was the norm of the day.

However, things do appear to be changing, and these trends are cause for concern. In recent years, scientists, through the media, have been informing the public about developments concerning sea ice in our northern hemisphere. Articles such as “As Polar Ice Turns to Water, Dreams of Treasure Abound” (the New York Times) recall the economic forces at play several centuries ago, while making a scientifically based prediction that the Arctic ocean may become the next, and likely one of the last, of our great oceans to exploit, conserve and protect.

Sea ice occurs at both poles as a result of large scale variations in solar insolation (incoming solar radiation or the sun’s rays) and changes in oceanic and atmospheric circulation driven by the seasonal global balance in net energy. An oscillating planetary energy balance is established with net positive surplus at the equator and net loss at the poles. Seasonal modulation of this general pattern is driven by the fact that the planet’s axis of rotation is 23.4° offset from the perpendicular. This means that solar insolation is much larger at the equator than at the poles, and this sets up (at least in a first order fashion) the seasons that create polar sea ice. It also results in an overall planetary energy balance with opposing signs at each pole, which helps to establish a planetary-wide circulation of heat from the equator poleward and vice-versa.

In the Arctic, sea ice forms annually throughout most of the area north of the Arctic Circle whenever the ocean dips below -1.8°C. Maximum volume of ice occurs around the end of March, with an area of about 14 million km2. Perennial ice occurs throughout the Canada and Arctic basins in the summer, and annual ice grows over the shallow continental shelves northward to meet the southern advance of the perennial pack. Reduction in this maximal extent occurs throughout the summer season until a minimum of about 7 million km2 is reached, sometime around the end of September.

Climate models converge on a single feature: they predict the first and strongest signals of global-scale climate change to occur in the high latitudes of our planet. These models predict a reduction in sea ice extent over the next several decades, resulting in a seasonally ice-free Arctic as early as 2050. Observational studies, based on the passive microwave satellite record, confirm these predictions for both rates of reduction and, to a certain extent, geographic location.

We lose, on average, about 74,000 km2 of sea ice extent each year, and we have lost about 2,000,000 km2 since 1979. The record of minimums has become rather common in the instrumental record, with the minimum on record being that of 2005. It is important to note that this reduction represents a switch from perennial ice (i.e., multiyear ice) to annual ice (i.e., firstyear ice). The issue of a reduction in ice thickness (volume), although more difficult to measure, also suggests an overall reduction. Recent results provide compelling evidence for an overall northern hemisphere volume decrease of 32 percent, most of which resulted from a reduction in thickness of ice over 2 m (i.e., multiyear). This coincided with an increase in the extent of open water and young ice of between 20 and 30 percent.

Minimum sea ice concentration (SIC) is defined as 15 percent concentration, and is computed for the end of September of each year using the SMMR and SSM/I passive microwave record (National Snow and Ice Data Centre [NSIDC]).

The timing of the reduction in the perennial ice cover is important, both from biophysical and socioeconomic perspectives. The barriers to navigation have historically been caused by multiyear sea ice, because it is thicker and harder than first-year sea ice. The decrease in the summer minimum means that multiyear sea ice will be less of a problem for marine vessel transport if the current trends continue.

Many researchers believe that the Northeast Passage will be one of the first to open, since the remnant pack tends to shift toward North America under current forcing. Two of us were in fact aboard a Russian ice-breaker in September 2005, and there was no ice of any significance to shipping along the entire route of the Northeast Passage (between Norway and Alaska). The situation with multiyear sea ice in the Northwest Passage is somewhat more complex. Historically, multiyear ice has moved into the archipelago through the channels on the western side of the archipelago (e.g., Amundsen Gulf, McClure Strait and small channels on the western edge of the QEIs). When the multiyear pack regularly extended southwards to the Tuktoyuktuk Peninsula we could find multiyear sea ice in Amundsen Gulf. In recent years, the pack ice edge has retreated north, and it now lies at the northern limit of McClure Strait. Once this edge retreats beyond the entrance way to McClure Strait we can expect a dramatic reduction in the amount of multiyear sea ice moving into the Northwest Passage. Given the current trajectory, this will likely happen in the next decade.

After a million years of evolution, Arctic species present unique features and life cycles that reflect adaptation to life on, in and under sea ice. The polar bear is impressively suited to detect and kill seals in the whiteness of the pack ice. Seals give birth to and nurse their pups in dens built inside sea-ice ridges. Juvenile Arctic cod, which live in the anfractuosities of the pack where they are protected from their predators and find abundant crustacean prey, synthesize antifreeze proteins that prevent their blood from freezing at the sub-zero temperatures prevailing in the ice. Key Arctic copepods have developed sophisticated reproduction strategies to match the hatching of their eggs with the short season of production of ice algae. In addition to microalgae, bacteria dwell in the high-salinity brine channels among the sea-ice matrix and are active at temperatures as low as -22 C. Life in the Arctic seas begins in mid-spring, when the snow covers become sufficiently thin to allow enough sunlight to reach the base of the ice. The light reaching the ice-water interface triggers the growth of icedwelling microalgae. As the ice cover breaks up in early summer, sunlight penetrates deeper into the ocean and free-floating microalgae known as phytoplankton start blooming. Minute crustaceans called copepods (from 0.2 to 2 cm long) emerge from hibernation at depth to graze on the ice algae and phytoplankton. The copepods are preyed upon by the ubiquitous Arctic cod, a small (25-30 cm) sluggish cousin of the Atlantic cod that in turn is the main staple of seals, belugas, narwhals and many species of sea birds. At the top of the food chain, the polar bear preys almost exclusively on the ring seal, whereas man hunts any large prey, including the polar bear. The fat reserves accumulated in summer by the small herbivore copepods sustain them during the long winter months and sustain their predators throughout the annual cycle. As their icy habitat shrinks and thins, these highly specialized organisms face the double threat of displacement by less specialized temperate species, and extinction. At the root of the food chain, ice algae are more abundant, more productive and more diversified in the thin, soft and porous annual ice than in the thick, hard and dense multiyear ice. Thus, in the short term, the replacement of multi year ice by first-year ice and a general thinning of the snow and ice covers could lead to higher micro algal production. In the longer term, the more productive phytoplankton will replace the ice algae as the ice season shortens and the Arctic Ocean becomes ice-free in summer. Fewer ice algae and a longer phytoplankton bloom will mean an overall more productive peripheral Arctic Ocean.

However, a shift in micro algal production toward an earlier and longer phytoplankton bloom will also spell the replacement of Arctic copepods by Atlantic cousins that are already becoming common in Arctic seas. Coupled with a reduction in sea ice habitat and a warming of the ocean surface layer, the “atlantification” of the plankton will have a tremendous impact on the capacity of the Arctic cod to resist displacement by temperate fishes. Such a displacement is already observed in northern Hudson Bay, where a shift in the diet of seabirds from nearly pure Arctic cod in the 1980s to a 50-50 mixture of cod and capelin nowadays has been attributed to the lengthening of the ice-free season. Less ice habitat and fewer Arctic cod will also affect the ring seal, potentially bringing about its replacement by more coastal species such as the harbour seal, with devastating consequences for the polar bear and the traditional hunting activities of the Inuit.

Given the observed rate of the northward progression of temperate fish in response to the warming of the Atlantic Ocean, new fisheries resources could develop rapidly over the next century in an ice-free Arctic Ocean. However, given the low temperatures that will always prevail in polar waters, the growth of newly immigrated fish will be slow and the stocks will be highly vulnerable to over fishing. The richer, biologically more productive surface waters of an ice-free Artic Ocean will contribute to the sequestration of atmospheric carbon, thus mopping up some of the greenhouse gases emitted by human industry. On the other hand, sea-ice reflects 90 percent of the sun’s radiation into space, compared to less than 30 percent for open waters. Therefore, an ice-free Arctic Ocean will absorb much more heat from the sun, accelerating the warming of the Northern Hemisphere, and all preliminary calculations indicate that the increase in the radiative heat balance of the Arctic will far exceed any reduction of the greenhouse effect. The ongoing reduction of sea ice presages a biologically more productive and more diverse Arctic Ocean that will, however, differ little from the northernmost reaches of the Atlantic. There is no common scale against which to compare the loss of biodiversity and the gain in biological productivity that will result from the “atlantification” of the Arctic Ocean.

Environmentalists will rightly perceive it as a tragic loss to the global ecosystem. Neo-liberals already see it as a potential Klondike. In any case, there is no doubt that the unregulated exploitation of the new or newly accessible resources of the Arctic will end in catastrophe, as it has in other oceans. Hence the importance of Canada strongly asserting its Arctic sovereignty and its authority to control and manage the exploitation of the resources of its Arctic shelf, including the straits of the Canadian Archipelago. In addition to fisheries, changing ice conditions in the Northwest Passage could provide a sea route between Asia and Europe that is 7,000 kilometres shorter than the route through the Panama Canal. The passage could also accommodate supertankers and container ships that are too large for the canal. Some Japanese and American companies are already building ice-strengthened vessels. But, any shipping involves the risk of accidents, particularly oil spills, and authority to regulate foreign vessels in the passage could soon be lost, since any foreign ship that transits without seeking permission undermines Canada’s sovereignty claim.

The history of Canada’s claim to the Northwest Passage is fraught with confusion and indecision. Initially, it seemed that title over the waterway did not matter, because of the nearly impenetrable ice. Still, a claim to the water was at least implicit in an assertion, first made in the late 19th century, that Canada owned everything between the 60th and 141st meridians of longitude all the way to the North Pole. But, apart from the Soviet Union, which attempted a similar claim, other countries rejected the sector theory.

In 1969, an American oil company sent an ice-strengthened tanker, the SS Manhattan, on a test voyage through the passage. The company, which was cooperating closely with the US government, made a point of not seeking permission from Canada. Ottawa made a point of granting permission, and even sent an icebreaker to assist, and subsequently argued that the unsolicited permission prevented the voyage from undermining its claim. A more convincing defence of sovereignty came from an unexpected source. As the SS Manhattan ploughed through the ice near Resolute Bay, two Inuit hunters drove their dogsleds into its path. The vessel ground to a halt, until the hunters— having made their point— moved aside.

The following year, Parliament adopted the Arctic Waters Pollution Prevention Act, imposing stringent safety and environmental requirements on all shipping within 100 nautical miles of the Arctic coast. The claimed right to pollution prevention jurisdiction was contrary to international law, which at the time did not recognize coastal state rights beyond the territorial sea. But it was subsequently made legal by the 1982 United Nations Convention on the Law of the Sea, which allows coastal states to impose laws against maritime pollution out to 200 nautical miles when virtually year-round ice creates exceptional navigational hazards. A second piece of legislation extended the territorial sea from 3 to 12 nautical miles. This move was less controversial, since 60 other countries had made similar claims. Its immediate relevance lay in the fact that the passage, at its narrowest points, is less than 24 nautical miles across. As the Canadian government explained, the overlapping territorial seas meant that foreign vessels making the passage could be subject to the full range of its domestic laws. At the same time, Canada began arguing that the straits and channels between the islands were “historic internal waters.”

This argument rested on the fact that most of the archipelago had been mapped by British explorers prior to the transfer of title, and few nonconsensual transits had occurred. Canada also pointed out that the Inuit— who are Canadian citizens— had travelled and lived on the ice for millennia. There was, however, some contradiction between the territorial sea and historic internal waters arguments, since internal waters are by definition not territorial sea. The confusion gave strength to the US position, which holds that the passage is an “international strait.” International straits are narrower in breadth than the adjoining territorial seas but, because they join two expanses of high seas, they are open to foreign shipping with almost no restrictions. More than commercial shipping was at issue. During the Cold War, the United States was concerned to maintain open access for its Navy, especially its submarines. Under the law of the sea, submarines may pass through an international strait without surfacing or otherwise alerting the adjacent coastal state or states, something not permitted in territorial waters.

In 1985, the US Coastguard icebreaker Polar Sea sailed through the passage, again without seeking permission. Ottawa once again made a point of granting permission; it even asked to place several “observers” on board. Remarkably, Washington acceded to the request, strengthening Canada’s argument that the transit was consensual, and even promised to provide advance notice of any future transits by Coastguard vessels. Yet it still made a point of publicly disputing the sovereignty claim. Following the voyage of the Polar Sea, Canada again modified its legal position. Central to the new position was the drawing of straight baselines linking the outer headlands of the archipelago.

As the result of a decision by the International Court of Justice in a dispute between Britain and Norway, strait baselines had become a legally accepted means for determining the extent of coastal state jurisdiction along fragmented coastlines. Canada invoked its prior claim of historic internal waters in support of its new baselines, arguing that its title to the waters within the baselines— which by definition are internal waters— was consolidated by historic usage. The argument was reinforced in 1993 by the Nunavut Land Claims Agreement, whereby the Canadian government and the Inuit affirmed that “Canada’s sovereignty over the waters of the arctic archipelago is supported by Inuit use and occupancy.” The historic consolidation argument is also supported by several judgments of the International Court of Justice. However, Canada’s overall claim is weakened by the fact that it lacks enforcement capability. Despite having the world’s longest coastline, much of it ice-covered most of the time, Canada has never possessed an icebreaker capable of operating in the Arctic year-round. In 1985, the Canadian government announced that it would build a powerful all-season icebreaker. But fiscal restraint quickly became a greater priority than sovereignty, and the contract was cancelled.

Canada’s does have a fleet of Aurora patrol aircraft which were are now used mostly for fisheries protection. But only one or two flights per year are devoted to “sovereignty assertion.” The Canadian Airborne Regiment was once able to deploy 1,000 soldiers on short notice anywhere in Canada, but it was disbanded after paratroopers tortured and killed a Somali teenager. Canada’s sovereignty claim is defended primarily by the Canadian Rangers: 1,600 part-time volunteers who live in 58 hamlets scattered across the North. The Rangers know the land and ice and provide an effective— if slow-moving— searchand-rescue capability, yet their abilities are dwarfed by the expanse in which they operate: Canada is the world’s second largest country, and more than 40 percent of it is Arctic.

In practice, neither fisheries laws nor the Arctic Waters Pollution Prevention Act can be applied. And as the ice disappears, Canada’s sovereignty claim is vulnerable to more foreign vessels, including submarines, using the Northwest Passage without seeking permission— as they might wish to do in order to evade Canada’s environmental laws.

Prime Minister Paul Martin declared in November 2004 that sovereignty “is an issue which is becoming even more important, given climate change and the opening of the Northwest Passage to transportation, and the environmental problems that may flow from that.” Some steps are now being taken. Auroras are being equipped with infra-red sensors, and unmanned aerial vehicles are being acquired to provide long-range surveillance at lower cost. As of 2006, Radarsat-2, a federally funded remote sensing satellite will provide up-todate, high resolution imaging on demand— giving Canada the ability to track surface vessels from space. Yet more needs to be done.

Canada offers a registration service to all ships entering its northern waters. But the service has always been voluntary. Making registration in the Arctic mandatory would bolster sovereignty.

The Department of National Defence is deliberating whether to install high-frequency surface-wave radar at the entrances to the passage. The time for deliberation is over. The information obtained would be useful to the Canadian Forces and Coastguard and the presence of the installations would strengthen Canada’s legal position. At least two all-season Arctic icebreakers are needed— one each for the eastern and western Arctic.

One or more of these vessels could be outfitted to conduct the types of science currently being done aboard the NGCC Amundsen. Several helicopters should be based near the northwest passage to provide search-and-rescue and ensure that suspicious vessels are boarded and inspected.

Most importantly, it is time to persuade Washington to change its outdated position. Today, the United States is more concerned about terrorists finding a back door to North America, or rogue states using the oceans to transport weapons of mass destruction, than it is about foreign submarines. In the Arctic, these new threats could just as easily be handled by a strengthened Canadian Coastguard and Navy, whose abilities would be enhanced if Canada’s domestic laws could fully be applied.

It does not serve the interests of either country to have foreign vessels shielded from those laws, and most of international law, by maintaining that the passage is an international strait.

Given what we know about feedbacks in the Arctic system, it is increasingly likely that sea ice reduction will not be reversed. The minimum we reached in 2005 has never before been seen in any of our instrumental records and the projection of a seasonally ice free Arctic by about 2050 has not been seen on planet Earth for at least a million years. As a polar country, Canada has a particular interest and responsibility to protect the fragile Arctic and its indigenous peoples. But that should not distract from the more urgent policy imperative: reduce greenhouse gas emissions so as to slow and eventually halt climate change, before it is too late. The Arctic is our canary in the coal mine.

This paper is a contribution of ArcticNet, a new network of centres of excellence (www.arcticnet-ulaval.ca/)