Speaker details dynamic ice’s effects
By Bridgette Taylor, The Dartmouth Staff
Published on Tuesday, March 2, 2010
The dynamic nature of ice in the Arctic region has caused significant ecological damage and jeopardized the lifestyles of several Arctic species, according to Stephanie Pfirman, chairman of the environmental science department at Barnard College. Such ecological changes will come sooner than scientists had previously anticipated, Pfirman said in a lecture, “The Last Arctic Sea Ice Refuge,” in Steele Hall on Monday.
“We knew that warming was going to have an effect on ice,” Pfirman said. “We are now in a new phase — much more warming and a more steady [ice] decrease.”
The ice in the Arctic interior has decreased significantly as new thinner ice replaces old thicker ice, which gives the region an unforeseen and evolving character, according to Pfirman.
“The wind aligned perfectly in 1989 to push a lot of the old ice out, which left the Arctic a lot more vulnerable,” she said. “There was a dramatic decrease in the age of ice, and a decrease in the ice’s thickness.”
The region’s ecosystem will dramatically change as the ice continues to disappear, according to Pfirman. While Arctic birds and walruses may soon struggle to locate food sources, polar bears are in particular danger, she said.
“Polar bears like to hang out near the breathing holes of seals,” Pfirman said. “When the ice disappears, the polar bears will not be able to find the seals.”
The polar bear habitat will likely decrease throughout the Arctic except for one particular region, Pfriman said. In that strip, dynamic ice movement may give way to complex ice structures that would be stable enough to support polar bears, but thin enough to sustain seals, she said.
The changing ice qualities will also carry pollutants throughout the area, which could destroy the ecosystem of the central Arctic basin, according to Pfirman.
“When you have sediments [in the ice], then the contaminants are likely to be retained in the ice,” she said. “The ice releases its entire sediment load over the central part of the basin.”
Pollutants have created hormonal imbalances in certain Arctic species, Pfirman said. She added that scientists have recently discovered hermaphroditic polar bears, a trend that could have been caused by the pollutants.
Not all consequences of a disappearing ice cap are negative, Pfirman said. The Northwest Passage, a sea route that connects the Pacific and Atlantic Oceans that is generally blocked by ice, may open up and create trade opportunities, according to Pfirman.
By taking the Northwest Passage or the Northern Sea Route, “you can cut 40 percent of the time shipping requires,” she said.
The Arctic area may also yield oil and natural gas reserves, which has piqued the interest of countries including Russia and Canada, Pfirman said.
“Changes have really affected how countries are looking at the poles,” she said.
Although the polar ice cap’s size has progressively diminished, Pfirman said she expects that one specific region north of Greenland will retain ice cover well into the future.
“Because the ice is dynamic, you will have some places that retain ice much longer than others,” she said.
To protect the remnants of the polar ice cap, Pfirman proposed a sustained effort to monitor the Arctic Ocean and Arctic Sea, as well as a projection and refuge management strategy.
“We need a large ecosystem-based management regime to protect the integrity of the Arctic,” she said. “We need to be thinking about managing this refuge for decades into the future.”