The Arctic Ocean, which is normally blanketed in sea ice, is losing more and more of its ice cover. Since satellites began to monitor Arctic in the 1970s, sea ice has been steadily retreating, with ice cover declining by as much as 50%. Adding to the problem, newly formed ice is much thinner, making it prone to melting.
Loss of sea ice will impact polar bear survival. Bears need ice to access their hunting grounds. It will also open the Arctic to economic exploitation, from new shipping routes to oil and natural gas exploration.
As sea ice declines, the Earth’s ability to reflect sunlight will diminish, causing the waters of the Arctic Ocean to warm.
Crystalline and white, ice has what scientists call a “high albedo.” Simply put, this means it reflects back much of the sunlight that hits it. Albedo is what makes you reach for a white shirt on a sunny day; it also helps explain why black parking lots are so hot.
As “high albedo” Arctic sea ice melts away, the ocean’s darker “low albedo” waters will become more effective at absorbing solar radiation. And warmer waters will mean less ice.
Glaciologists predict that the Arctic will be ice-free within a couple of decades.
“Any little bit of climate warming that’s caused by emissions of fossil fuels and other human impact in more populated parts of the globe, become amplified,” says Terry Chapin, an ecosystem ecologist at the University of Alaska Fairbanks. “And so it magnifies the total rate at which climate will continue to warm and that’s going to affect everybody throughout the world. So it’s not just an arctic issue, it’s a global issue.”
Sea ice retreat is just one of the many ills facing our planet as a result of climate change, underscoring the need for a low-carbon future. Now, more than ever, we must anticipate the costs of inaction.
Web Extra
Terry Chapin, an ecosystem ecologist at the University of Alaska Fairbanks, discusses the long-term consequences of melting sea ice…
[audio:http://wamcradio.org/EarthWise/wp-content/uploads/2012/01/Chapin_web.mp3|titles=Chapin_web]Photo, taken on April 14, 2007 using a Canon PowerShot S50, courtesy of Sanna Pudas via Flickr.