sciam.com: By David Biello

Efforts to repair a giant breach in the stratosphere could make global warming worse.

Decades of chemical pollution have damaged the ozone layer of the upper atmosphere that shields Earth from the harmful effects of the sun’s ultraviolet rays, each summer eating a hole over the South Pole that expands to nearly the size of Antarctica. But since 1996, when an international treaty banned the culprit chemical refrigerants and propellants (known as CFCs, or chlorofluorocarbons), the size of the seasonal tear has been shrinking—and scientists predict it may stop forming by the end of this century.

You would think that was good news. But atmospheric scientists caution in a new study published in Science that sewing up the rift in the ozone (a type of oxygen) layer may exacerbate another environmental woe: climate change. [ read more ]