Can We Save the Polar Bears?

Later today, the National Snow and Ice Data Center will announce exactly how much Arctic ice has melted and experts expect to hear that Arctic sea ice covers just 1.7 million square miles — a record low.

The loss of Arctic ice means more bad news for the already ill-fated polar bears. Less ice translates to less homeland for polar bears.

On the great Greenland ice sheet, which is 2 miles thick at twice the altitude of Denver, American scientists have established a summit camp.

The terrain around the camp may hold important clues on how to save a lot of rapidly melting Arctic ice, including the polar bears' habitat.

Scientists are discovering that what appears to be pristine, white snow may be more polluted than it seems. They're finding tiny particles of black carbon — too small for the naked eye to see — from forest fires and human pollution.

Under a microscope, scientists can see black carbon particles by the trillions. Those black carbon particles cause the snow to melt faster.

"Black carbon absorbs sunlight and it causes warming," said Stephen Warren, an atmospheric scientist at the University of Washington.

Scientists have traced soot blown into the Arctic region to industrial sources in North America, Europe and now Asia, but there's still hope.

"I think we can still save the Arctic," said NASA's James Hansen. "Our calculations are that we could keep the sea ice in the Arctic from melting much more than it has already."

That can only happen if emissions cuts include greatly decreasing black carbon from smokestacks and tailpipes, according to Hansen and other scientists. That's an effort everyone has to strive for, from China to the United States.