Arctic Meltdown Opens Fabled Northwest Passage

obmar · Site Admin Joined: 14 Apr 2006 Posts: 5697

http://www.livescience.com/environment/070914_northwest_passage.html
Arctic Meltdown Opens Fabled Northwest Passage

By Ker Than, LiveScience Staff Writer

posted: 14 September 2007 02:59 pm ET

A fabled sea route above North America linking the Pacific and Atlantic Oceans has become a reality thanks to global warming.

Scientists have confirmed that in August, Arctic sea ice shrank to its lowest levels since satellite measurements began monitoring the region nearly 30 years ago. One consequence of this is that the Northwest Passage has opened up much earlier than expected.

"We're several decades ahead of schedule right now," said Mark Serreze, a senior scientist at the University of Colorado's National Snow and Ice Data Center, which monitors the region.

The premature opening of the passage does not mean that climate models are unreliable, only that their predictions have been far too conservative, Serreze said. "They're getting the right trajectory, but they're too slow," he said.

Shorter sailing

The legendary passage was first navigated with great difficulty and using a relatively small ship by explorer Roald Amundsen in 1903 to 1906. Predictions for the opening of the Northwest Passage have ranged from 2012 to 2080 at their most conservative.

Fully navigable, the Northwest Passage will make the trip 4,000 miles shorter for ships traveling between Europe and Asia, allowing them to avoid the Panama Canal. The Passage was partially open for a time in 1998, but sailing a ship through at time would have been tricky, Serreze said.

"I wouldn't have wanted to try it" in 1998, Serreze told LiveScience. "Through the years, it's become increasingly open, but still really had not remained open in any kind of viable way. 2007 is really the first year."

A ship attempting the passage now would have "clear sailing," Serreze said. "You'd go in through the Bering Strait between Alaska and Siberia, then a little north of Banks Island and then go through the passage."

Scientists predict that the Northwest Passage will be open much more frequently from now on, but that it will still not be a year-round option for ships. "Ice will still be there in the winter, because even in the greenhouse-warmed world, there's winter in the Arctic," Serreze said.

The premature opening of the Northwest Passage could mean that the Artic Ocean in general could be ice-free much earlier than climate models have predicted. "The notion of coming to an ice free Arctic Ocean even by 2030 is not totally unreasonable," Serreze said.

Models previously predicted the ice would clear sometime around the middle of the century.

Reasons unclear

Recent observations by the European Space Agency's Envisat satellite have shown that from 2006 to 2007, ice in the Arctic decreased by about 386,000 square miles (1 million square kilometers).

"The strong reduction in just one year certainly raises flags that the ice (in summer) may disappear much sooner than expected and that we urgently need to understand better the processes involved," said Leif Toudal Pedersen of the Danish National Space Center.

It could be that natural climate processes are helping to accelerate the effects of global warming, Serreze said.

"We're scratching our heads right now," he said. "There's a lot of factors that can be involved here."

obmar · Site Admin Joined: 14 Apr 2006 Posts: 5697

Arctic sea ice shrunk this week to its lowest level since satellite measurements began nearly 30 years ago, so much that it has opened up the most direct route of the Northwest Passage--a legendary frozen sea route above North America and Siberia linking the Atlantic and Pacific oceans.

Arctic sea ice normally recedes in the summer, but satellite data collected by the European Space Agency's Envisat probe, has shown that the overall rate of ice loss has sped up drastically in the past 10 years.

"There has been a reduction of the ice cover over the last 10 years of about 100,000 square kilometers [62,137 square miles] per year on average," said Leif Toudal Pedersen of the Danish National Space Centre, "so a drop of 1 million square kilometers [621,371 square miles] in just one year is extreme."

While the Northeast Passage along the Siberian coast remains partially blocked, the Passage's most direct route now is navigable across northern Canada. However, Pedersen says, the complete passage may open sooner than expected.

The fabled Northwest Passage, if fully navigable, could make the trip 4,000 miles shorter for ships traveling between Europe and Asia if they could avoid the Panama Canal route. The passage was first navigated by explorer Roald Amundsen in 1903 to 1906.

Even when the Arctic ice pack dropped to a previous low of 4 million square kilometers in 2005, the passage did not fully open, Pedersen said.

Earth's polar regions are highly vulnerable to rising temperatures spurred by climate change. While the UN’s Intergovernmental Panel on Climate Change predicts an ice-free Arctic summer by 2070, other scientists foresee such a scenario as early as 2040.

The Inquisitor · Joined: 17 Jun 2006 Posts: 772

This is very serious. The melting of the polar ice cap as well as the Greenland ice cap will make our oceans rise by several meters causing entire cities to be inundated.

obmar · Site Admin Joined: 14 Apr 2006 Posts: 5697

It is serious. Bery serious indeed.