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Submitted by George Elliott on Fri, 09/07/2012 - 1:38pm.
The Arctic Ocean’s vast, frozen expanse of ice is rapidly vanishing. Recently scientists reported a record shrinkage of the extent sea ice. Greenland, the vast frozen land of freshwater continues to shrink more rapidly during the summer months than it can refreeze in the winter months, making a net loss of ice. And since this is frozen freshwater (not like the ice burgs that float in the oceans like ice cubes in a glass of soda, for example), melting of such raises sea levels and changes the salinity of the oceans, both of which have major impacts on climate, lifestyles, and marine life.
It’s clear that Arctic sea ice is now shriveling more quickly each year. And scientists say the melt has been driven by both global warming and other pollutants that humans have put into the atmosphere. So why does the disappearing sea ice actually matter? Partly it’s a sign of how quickly we’re heating the planet. Yet the vanishing sea ice can also have its own side effects, from warming up the Arctic further to unlocking once-frozen areas of the north for oil and gas exploration.
Over the past three decades, the summer Arctic sea ice extent has declined roughly 40 percent, and the ice has lost significant volume, according to data from the Polar Science Center. There will be ups and downs, but we are on track to see an ice-free summer by 2030.
A new study in this month’s Environmental Research Letters concludes that between 70 and 95 percent of the Arctic melt since 1979 has been caused by human activity. Man-made global warming has rapidly heated up the Arctic — the region has been warming about twice as fast as the global average. What’s more, soot and other pollutants from smokestacks in Europe and Asia have traveled up to the Arctic. When those dark particles settle onto the snow and ice, they absorb sunlight and start warming.
Ice that’s floating in the ocean can’t raise sea levels when it melts, because the ice was already displacing its own volume. But as the exposed ocean absorbs more sunlight, the region will keep heating up.
Greenland’s ice sheet is 1.9 miles thick and contains enough ice to raise global sea levels by about 25 feet. As a result, a recent study by the U.S. Jet Propulsion Laboratory predicted that sea levels are on pace to rise at least a foot by 2050, and possibly three feet by century’s end.
The amplified warming in the Arctic might well be contributing to extreme weather.
First, the west-to-east jet stream appears to be slowing down, which allows weather patterns to persist in certain areas for longer. This could help account for the onslaught of snowstorms in the United States and Europe in 2009 and 2010, as well as prolonged heat waves like the one that hit Moscow in 2010. Arctic amplification can also increase the "waviness" of the jet stream surrounding the polar region. That could allow more frequent blasts of cold Arctic air to escape down into North America or Europe, leading to frigid winters.
The melting Arctic sea ice makes it easier for oil and gas companies to explore northern offshore regions that were once inaccessible. This is another little-discussed Arctic “feedback” — less ice means more oil and gas which, when burned, will heat the planet further.
Have we reached the point of no return? Perhaps, but no one knows for sure. Modeling obviously shows that corrective action taken by humans today will eventually help, but maybe even more practical insofar as taking corrective action now is that it’s good for our health, from reductions to pollutants to more efficient methods of energy production.
By: George Elliott