What Happens To Polar Bears As Arctic Ice Shrinks?

Published January 16, 2010 at 12:00 AM EST

Imagine if that incredible expanse of Arctic ice on the top of the globe were to turn into blue ocean. What would happen? That's the question Alun Anderson asks in his new book After the Ice: Life, Death and Geopolitics in the New Arctic..

Anderson, former editor-in-chief of New Scientist magazine, says at the rate the sea ice is melting, by the summer of 2050, the Arctic will be a mostly open ocean.

"The polar bear is the king of the Arctic, the top predator. It'll be gone," Anderson tells Weekend All Things Considered host Guy Raz. "A killer whale living in open water will be the symbol of the Arctic, replacing a bear on ice. And that's an astonishing change."

Anderson says as the ice melts, it will take several forms of "revenge" on those living south of the Arctic.

"Once the tundra that rims the Arctic starts to thaw, what we'll see is greenhouse gases pouring out of that tundra," Anderson says. Those gases include methane and carbon dioxide, and they'll contribute to climate change, he says.

Another problem: rising sea levels. As the ice cap sitting on top of Greenland melts, it pours into the sea. Anderson says if the entire cap melts, sea levels worldwide will rise by 20 feet or more.

"It'll take hundreds, probably thousands of years for all the ice to melt, but once it gets going, once it really gets going, it will become unstoppable," he says. "The ice that sits on top of Greenland, not the sea ice, is a little bit different. We have more chance to save that, quite definitely. But the ice that fills that ocean is going, and I don't think we're able to stop it."

Anderson says that will also have a huge impact on the people who live and hunt in the Arctic, and it will open up a bunch of new geopolitical headaches for the countries rimming the Arctic Circle.

As the ice melts, the Arctic area becomes more accessible -– as does the 90 billion barrels of oil the U.S. Geological Survey estimates are beneath the Arctic Ocean.

"As it becomes accessible, you need to be able to police and patrol it," Anderson says, "and nobody has the capacity to police and patrol it at the moment."