But over Antarctica, the ozone layer is deteriorating. Scientists have found that low temperatures promote chemical reactions that lead to ozone depletion. The CFCs combine with ozone to form new molecules, reducing the amount of free ozone in the atmosphere. Although global efforts to find alternatives to CFCs have been fairly successful, ASU scientist Tad Day says that existing CFCs in the atmosphere will be around for at least 50 to 100 more years. The problems are not just in Antarctica.
Day says that an ozone hole can drift.
A second hole sometimes drifts down from the North Pole to Canada and over the United States. It's not just an Antarctic problem or even a polar problem anymore.