Posted by Marcia Divack on September 23, 2008 at 10:59pm
By Marsha WaltonCNN(CNN) -- Summer is over in the northern hemisphere, but it's been another chilling season for researchers who study Arctic sea ice.Disappearance of Arctic ice cover may affect storm systems, storm tracks and crops, according to researchers.1 of 2 "It's definitely a bad report. We did pick up little bit from last year, but this is over 30 percent below what used to be normal," said Walt Meier, a research scientist with the National Snow and Ice Data Center in Boulder, Colorado.This past summer, the Arctic sea ice dwindled to its second lowest level. Arctic sea ice is usually 1 to 3 meters, or as much as 9 feet thick. It grows during autumn and winter and shrinks in the spring and summer.Scientists have monitored sea ice conditions for about 50 years with the help of satellites. Changes in the past decade have been alarming to climate researchers and oceanographers."It is the second lowest on record. ... If anything, it is reinforcing the long-term trend. We are still losing the ice cover at a rate of 10 percent per decade now, and that is quite an increase from five years ago," Meier said. "We are still heading toward an ice cover that is going to melt completely in the summertime in the Arctic."Arctic ice helps regulate and temper the climate in many other parts of the world. The less ice there is, the more dramatic the impact. Huge sheets of ice reflect solar radiation, keeping our planet cool. When that ice melts, huge expanses of darker, open ocean water absorb the heat instead, warming things up.Although few humans live in the Arctic, the disappearance of this ice cover can have effects far beyond the few residents and the wildlife of this harsh region. Ice cover loss can influence winds and precipitation on other continents, possibly leading to less rain in the western United States and creating more in Europe.So, just how much ice is disappearing?Less than 30 years ago, there would still be 7 million square kilometers or 2.5 million square miles of ice left at the end of an Arctic summer. That's now dropped by almost 40 percent. See how much Arctic sea ice has disappeared »"Seven million square kilometers roughly corresponds to an area of the lower 48 United States. So back in the early 1980s, the lower 48 states would be covered in sea ice in the summer," Meier said. "Now we've essentially lost sea ice east of the Mississippi River and even beyond. So that's a significant amount of area."The best known consequence of disappearing sea ice in the Arctic is the loss of the polar bear habitat."The Arctic sea ice melt is a disaster for the polar bears," according to Kassie Siegel, staff attorney for the Center for Biological Diversity. "They are dependent on the Arctic sea ice for all of their essential behaviors, and as the ice melts and global warming transforms the Arctic, polar bears are starving, drowning, even resorting to cannibalism because they don't have access to their usual food sources."Scientists have noticed increasing reports of starving Arctic polar bears attacking and feeding on one another in recent years. In one documented 2004 incident in northern Alaska, a male bear broke into a female's den and killed her.In May, the U.S. Department of Interior listed the polar bear as a "threatened" species under the Endangered Species Act. In a news release, U.S. Interior Secretary Dirk Kempthorne stated, "loss of sea ice threatens and will likely continue to threaten polar bear habitat. This loss of habitat puts polar bears at risk of becoming endangered in the foreseeable future, the standard established by the ESA for designating a threatened species."What is the future for Arctic sea ice? Some scientists believe that in just five years, the Arctic may be ice-free during the summer."The Arctic is kind of the early warning system of the climate," Meier said. "It is the canary in the coal mine, and the canary is definitely in trouble."Read more…
Posted by Marcia Divack on September 4, 2008 at 2:30pm
TORONTO, Ontario (AP) -- A chunk of ice shelf nearly the size of Manhattan has broken away from Ellesmere Island in Canada's northern Arctic, another dramatic indication of how warmer temperatures are changing the polar frontier, scientists said Wednesday.Large pieces of ice are seen drifting off the Ward Hunt Ice Shelf in this July file photo.Derek Mueller, an Arctic ice shelf specialist at Trent University in Ontario, told The Associated Press that the 4,500-year-old Markham Ice Shelf separated in early August and the 19-square-mile shelf is now adrift in the Arctic Ocean."The Markham Ice Shelf was a big surprise because it suddenly disappeared. We went under cloud for a bit during our research and when the weather cleared up, all of a sudden there was no more ice shelf. It was a shocking event that underscores the rapidity of changes taking place in the Arctic," said Muller.Muller also said that two large sections of ice detached from the Serson Ice Shelf, shrinking that ice feature by 47 square miles -- or 60 percent -- and that the Ward Hunt Ice Shelf has also continued to break up, losing an additional eight square miles.Muller reported last month that seven square miles of the 170-square-mile and 130-feet-thick Ward Hunt shelf had broken off.This comes on the heels of unusual cracks in a northern Greenland glacier, rapid melting of a southern Greenland glacier, and a near record loss for Arctic sea ice this summer. And earlier this year a 160-square mile chunk of an Antarctic ice shelf disintegrated."Reduced sea ice conditions and unusually high air temperatures have facilitated the ice shelf losses this summer," said Luke Copland, director of the Laboratory for Cryospheric Research at the University of Ottawa. "And extensive new cracks across remaining parts of the largest remaining ice shelf, the Ward Hunt, mean that it will continue to disintegrate in the coming years."Ellesmere Island was once entirely ringed by a single enormous ice shelf that broke up in the early 1900s. All that is left today are the four much smaller shelves that together cover little more than 299 square miles.Martin Jeffries of the U.S. National Science Foundation and University of Alaska Fairbanks said in a statement Tuesday that the summer's ice shelf loss is equivalent to over three times the area of Manhattan, totaling 82 square miles -- losses that have reduced Arctic Ocean ice cover to its second-biggest retreat since satellite measurements began 30 years ago."These changes are irreversible under the present climate and indicate that the environmental conditions that have kept these ice shelves in balance for thousands of years are no longer present," said Muller.During the last century, when ice shelves would break off, thick sea ice would eventually reform in their place."But today, warmer temperatures and a changing climate means there's no hope for regrowth. A scary scenario," said Muller.The loss of these ice shelves means that rare ecosystems that depend on them are on the brink of extinction, said Warwick Vincent, director of Laval University's Centre for Northern Studies and a researcher in the program ArcticNet."The Markham Ice Shelf had half the biomass for the entire Canadian Arctic Ice Shelf ecosystem as a habitat for cold, tolerant microbial life; algae that sit on top of the ice shelf and photosynthesis like plants would. Now that it's disappeared, we're looking at ecosystems on the verge of distinction,' said Muller.Along with decimating ecosystems, drifting ice shelves and warmer temperatures that will cause further melting ice pose a hazard to populated shipping routes in the Arctic region -- a phenomenon that Canada's Prime Minister Stephen Harper seems to welcome.Harper announced last week that he plans to expand exploration of the region's known oil and mineral deposits, a possibility that has become more evident as a result of melting sea ice. It is the burning of oil and other fossil fuels that scientists say is the chief cause of manmade warming and melting ice.Harper also said Canada would toughen reporting requirements for ships entering its waters in the Far North, where some of those territorial claims are disputed by the United States and other countries.Ok, so since the ice is melting anyway, we might as well drill for oil? Such ignorance!Read more…
