Amid our heated political debate on climate change, it's cold air that apparently depleted the Arctic's ozone layer, the BBC reports. An article in the journal Nature says an 80% reduction of Arctic ozone, noted earlier this year, was caused by cold air hanging around the stratosphere for months longer than usual. But no one knows why it hung around so long. "That will be studied for years to come," one scientist says.
Even though it seems counter-intuitive, climate change may be the cause, the New Scientist reports. "Climate change warms the surface but cools the stratosphere," one scientist explains. A 2007 climate change panel concluded that "there has been global stratospheric cooling since 1979," but the exact cause hasn't been proven. But scientists have documented the ozone-destroying effect of chlorofluorocarbons in the Antarctic, which led to their ban in products like refrigerators and fire extinguishers. (Read more ozone layer stories.)