ELLESMERE ISLAND - On April 13, a patrol of Canadian Rangers arrived at Eureka, a remote weather station in the southwest part of Ellesmere Island.

For more than two weeks the patrol had been trekking across Canada's northern archipelago as part of Operation Nunalivut ("this land is ours"), a now-yearly exercise carried out by the Canadian Forces to assert the country's sovereignty in the High Arctic.

A month later, Prime Minister Stephen Harper and Minister of National Defence Peter McKay unveiled the latest iteration of the Canada First Defence Strategy.

The war in Afghanistan remains the focus. But the defence strategy also underlined a commitment to augmenting the Canadian Forces' capacity to "protect Canada's Arctic sovereignty and security."

While this hearkens back to the country's more traditional security concerns, it has been brought about by a very new security threat: that of climate change.

Arctic temperatures have been rising at almost twice the global average over the past 100 years, reducing sea ice by 2.7 per cent per decade. Under some scenarios, Arctic late-summer sea ice is projected to disappear almost entirely by the latter part of the 21st century.

With climate change increasing access to the Bering, Chukchi and Beaufort Seas, lucrative fisheries will develop as the ice recedes and cold-water fish move north.

The exploitation of the area's mineral deposits will become more cost-effective, and the region's vast oil and gas resources - which are believed to account for one-quarter of the world's undiscovered reserves - will ironically become more accessible due to climate change.

A well-publicized scramble for these resources is already underway, with Canada, Russia, the United States, Denmark and Norway all staking competing claims.

Russia has claimed rights over nearly half of the Arctic, and in August 2007 famously used a submarine to plant its flag on the seabed of the North Pole - a move described by a U.S. state department official as an unacceptable land-grab. Such tensions and disagreements are becoming more commonplace. According to the New York Times, "Claims of expanded territory are being pursued the world over, but the Arctic Ocean is where experts foresee the most conflict."

Control of the Arctic's natural resources depends to a large extent on the 1994 United Nations Convention on the Law of the Sea, which set out legal controls for marine natural resources and pollution.

The convention established the right to a maritime border that encloses an exclusive economic zone of 200 nautical miles from the coast. Countries can also apply to extend their maritime sovereignty beyond the 200-mile limit if the edge of the continental shelf extends further.

Canada ratified the treaty in 2003, and in 2006 launched an ambitious mapping exercise to define its maritime border as far as possible across the continental shelf.

The scope is enormous; the extended shelf of the Arctic and Atlantic Oceans alone is roughly the combined size of Manitoba, Saskatchewan and Alberta.

Along with new access to rich natural resources, the Northwest Passage could become a commercially viable navigation channel within the next 20 years.

Successive Canadian governments have argued that the Northwest Passage is Canadian territory, and in the interest of North American security (and the environment) Canada should control traffic in the passage, as opposed to allowing unfettered access.

The government's position stands in contrast to that of other maritime countries. The United States, for example, believes the Northwest Passage should be open to international traffic, and that vessels need not obtain consent from Canada before travelling through the strait; acceptance of Canadian sovereignty over the strait could set a dangerous precedent for other, equally strategic waterways such as those in the South China Sea.

To back up its stake, the Canadian government is investing heavily in equipment and staff to bolster its presence in the region. It has committed to building six to eight navy patrol ships to guard the Northwest Passage, and in August 2007 the Prime Minister announced plans to build two military bases in the region: an army training centre for 100 troops in Resolute Bay, and a deep-water port at Nanisivik on Baffin Island.

When the patrols of Operation Nunalivut set out in late March for their trek across Canada's Arctic, the team was not strictly made up of military personnel.

While primarily a display of Canadian military presence in the region, this year's operation carried with it a scientific team assessing the characteristics and stability of the ice shelves on Northern Ellesmere Island - indicative of the close linkages between security and the environment in the region.

It is clear that the environment and its management can no longer be viewed as a "soft" policy area - it can also have real security implications. The Arctic is changing, and Canadian security policy is changing with it.

To quote Inuit activist Sheila Watt-Cloutier, "As long as it's ice, nobody cares except us, because we hunt and fish and travel on that ice. However, the minute it starts to thaw and becomes water, then the whole world is interested."

© Copyright Toronto Star 2008