Ice retreat worries climate-change scientists

Sailing through the Northwest Passage? It should be smooth sailing. The Canadian Ice Service confirmed Friday that a southerly shipping route through Canada’s Arctic islands can now be safely navigated. (PHOTO BY JANE GEORGE)

RANDY BOSWELL
Postmedia News

Prime Minister Stephen Harper wrapped up his annual tour of the North on Friday amid fresh signs that the region has experienced another major meltdown this summer, including the renewed opening of the southern route of the Northwest Passage and a severe overall ice retreat still threatening to smash 2007’s record-setting thaw.

The Canadian Ice Service confirmed Friday that a southerly shipping route through Canada’s Arctic islands can now be safely navigated, though shifting winds could quickly send ice floes into a key strait near Nunavut’s Victoria Island and complicate any voyage through the Northwest Passage.

Meanwhile, the U.S.-based National Snow and Ice Data Center has released data showing total Arctic ice is once again retreating below the five-million-square-kilometre mark, meaning the five greatest melts since satellite measurements began in the late 1970s have occurred in the past five years.

The severe retreat includes the opening of vast stretches of the Beaufort Sea north of the Yukon-Alaska border, where Canadian and U.S. scientists are engaged in a joint seabed mapping mission aimed at securing undersea territorial rights for the two countries under a UN treaty.

That mapping effort, intended to provide a better picture of a sea floor mountain chain known as the Alpha Ridge, represents the last major data-gathering exercise for Canada ahead of its 2013 deadline for submitting offshore territorial claims to a UN body that approves ownership of the world’s continental shelves and the resources — principally oil and gas — they may hold.

Arctic Ocean ice typically reaches a maximum winter extent of more than 14 million square kilometres. It melts significantly during the summer months, usually reaching its minimum extent in mid-September.

The 30-year average for the end-of-summer minimum extent is about seven million square kilometres. But since 2007, when an unprecedented thaw reduced overall Arctic ice to just 4.13 million square kilometres by that September, the region has continued to experience distinctly below-average ice minimums.

The severe ice retreat being witnessed again this year in the polar regions of the Northern Hemisphere has many scientists concerned about the long-term impact of climate change, including altered wildlife habitats that appear to be threatening the future of ice-dependent species such as polar bear and narwhal.

At the same time, reduced Arctic ice promises major economic benefits for Canada through increased oil and gas exploration, shipping and tourism. Harper’s promotion of northern mining operations was a highlight of his visit to the Arctic this week, and increased development of northern resources is a major part of the Conservative government’s long-term vision of Canada as a mineral treasure-house and global energy superpower.

Still, environmentalists are sounding alarms about the grave risk of oil spills in Arctic waters that are now increasingly accessible to the petroleum industry but remain treacherous and notoriously difficult to deal with in an emergency.

And despite a clear trend toward better navigation in Canada’s Arctic waters, shipping through the Northwest Passage is expected to remain challenging in the near future as strong winds and currents push increasingly mobile ice floes in unpredictable directions.

Claude Dicaire, a forecaster with the Canadian Ice Service, told Postmedia News on Friday that while the southern route of the Northwest Passage is essentially clear, the same concentrations of ice in the Victoria Strait that famously doomed the 19th century Franklin expedition can quickly form in adverse weather conditions and menace ships today.

He said that the northern route of the passage, through the Parry Channel between Lancaster Sound in the east and the Beaufort Sea in the west, is still clogged with ice at certain points and may not open this year.

That said, Dicaire noted that in recent years the Northwest Passage has been opening up more consistently and earlier in the season, with a navigable southern route now typically appearing in August rather than in September.

“The ice is also thinner,” said Dicaire. He said he was surprised that the ice cover in the Northwest Passage “disappeared so quickly” this summer, but said the later freeze-up in winter lately means the ice that starts melting in summer is weaker to begin with.

“It forms so late,” he said, “there’s not as many months of winter to build the ice.”

Some scientists are predicting that ice-free summers could become the norm in much of the Arctic Ocean by 2030 or earlier.

But experts have said the Northern Sea Route — a shipping channel along the northern coast of Russia that could allow freighters to move more efficiently between Europe and Asia — is likely to be more reliably clear of ice, and for longer periods, than the Northwest Passage.