Polar Sea Ice May Expand Before It Disappears
Arctic sea ice is melting, but don't say goodbye just yet. A new study reveals that it may temporarily stop melting--or even expand--during the next several decades.
Scientists with the National Center for Atmospheric Research (NCAR) found that the melting Arctic sea ice may see periods of stability and growth as it disappears.
According to Jennifer Kay, the study's lead author, atmospheric conditions, like wind patterns, will vary enough in the coming decades to slow the rate of melting for up to 10 year periods. The good news comes in the wake of last month's observation that Arctic sea ice levels were the lowest for any July since 1979.
But Kay told the University Corporation for Atmospheric Research (UCAR) that these trends would not be permanent. “when you start looking at longer-term trends, 50 or 60 years, there’s no escaping the loss of ice in the summer," she said.
Kay's team found that “sea ice loss observed in recent decades cannot be explained by natural causes alone, and that the ice will eventually disappear during summer if climate change continues."
According to CBS News "summertime ice in the Arctic has shrunk by about a third since 1979."
About half of the sea ice loss in recent years can be blamed on human activity, the study found.
The research, which was published earlier this month in Geophysical Research Letters, suggests that Arctic ice will completely disappear by summer 2060.
Josefino Comiso, a senior cryospheric scientist with NASA, explained that increased melting creates a repetitive cycle. "If the area becomes warmer that means that the ice doesn't have as much time to grow. And in the process it's generally thinner every year than the previous year, and if it's thinner then it's more vulnerable to melt in the following summer," he told CBS News.
NCAR researcher Marika Holland recently told NPR that no one is exactly certain when the Arctic will see ice-free summers. She said her generation may live to see summers without any Arctic sea ice. But she said if “we don't live to see it, our children will."
NPR explains that future sea ice levels are hard to predict because the ice “is at the mercy of currents, cloud patterns and a host of other variables that change naturally from year to year.”
Earlier this month, the International Business Times reported that MIT researchers are concerned with the United Nations' most recent climate report. The MIT team claims that the 2007 UN report, from the Intergovernmental Panel on Climate Change, may “substantially underestimate” the rate at which the Arctic sea ice is melting. They argue that the ice may be thinning up to four times faster than previously predicted.
Scientists also found that melting Arctic ice may release trapped organic pollutants which are harmful to humans.
Despite these and other studies on climate change and receding polar ice, some U.S. political leaders remain skeptical.
--
Loading comments… 
First Posted: 08/25/11 06:44 PM ET Updated: 10/25/11 06:12 AM ET