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Part 3: The Arctic melt
In September 2007, the European Space Agency announced that the Northwest Passage was fully navigable for the first time since records began. Since Roald Amundsen’s successful crossing, 110 boats have successfully made it through the passage. Eighty were icebreakers or commercial ships with hardened hulls. But as the ice has receded, recreational ships have started to try their luck.
“There was hardly any ice,” Roger Swanson, a 76-year-old Minnesota pig farmer turned yachtsman, told the Wall Street Journal as he finished the trip. He had tried twice before, in 1994 and 2005, but had been turned back when the passage froze. “It has been a beautiful trip,” he said.
The North Pole’s ice grows and recedes with the seasons. In the darkness of winter, it fills in the Arctic Ocean, pushes up against northern Russia, slides down the coasts of Greenland, and stretches tentacles into the waterways of the Canadian Archipelago.
It seals up Hudson Bay and pushes through the Bering Strait all the way to Siberia. Under the summer sun, it forms a roundish cap, clinging to Greenland and northern Canada. Scientists track changes in the ice by measuring the amount left in the fall at the end of the melt season, when the sun starts to slip away. In 2007, the ice cover reached a new minimum, a 23 percent drop from the previous record in 2005.
A stretch of frozen white the size of Alaska, Texas and California was suddenly running with waves.
If the ice cover continues to shrink at its historic rate, by 2050 summers at the top of the world will be ice-free all the way to the North Pole.
It’s much more likely that the ice will disappear far faster, as breaking floes accelerate the warming of the Arctic.
“You have black ocean covered with a white surface,” Barber said.
“So when you get a lot of sunlight in the summertime, that white surface reflects the light back into space again. Remove that ice cover, and you’ve got a black surface, and it absorbs like crazy. All this energy coming in from the sun that used to be reflected to space is now being absorbed by the ocean.”
“Climate change is really changing the Arctic from an environment that used to have multi-year sea ice in the center, which is ice that survived a summer and went on the next winter to grow again,” said Barber. “It’s getting rid of that kind of ice and replacing it with first-year sea ice.”
The difference between first-year ice and the older ice of the central Arctic is the difference between limestone and marble. New ice never thickens more than two yards. Multi-year ice can grow to be eight yards thick. Leached of salt, it can be as hard as concrete.
“First-year sea ice is much easier to work with,” said Barber.
“It’s softer. It’s thinner. It’s more pliable. You can design icebreakers or drill ships to withstand first-year sea ice quite simple,” he said. “So when you say you have a seasonally ice-free Arctic, what that really means is you no longer have multi-year sea ice,” Barber said.
“It means shipping throughout the year will be very possible.”
Forecast: The global consequences of climate change
(Stephan Faris is the GlobalPost environment correspondent. His new book is "Forecast: The Consequences of Climate Change, from the Amazon to the Arctic, from Darfur to Napa Valley.")