Ozone hole largest on record over past 3 years, new research finds

Contrary to public perception, the Antarctic ozone hole has been among the largest on record over the past three years, according to new research. Researchers found that the ozone hole has been massive and long-lived over the past four years, and chlorofluorocarbons (CFCs) are not the sole cause. CFCs, known to contribute to ozone depletion, were regulated by the 1987 Montreal Protocol.