Copper-based chemicals may be contributing to ozone depletion

As Earth's ozone layer recovers from past emissions of now-banned CFCs and halons, other chemicals are emerging as major causes of stratospheric ozone depletion. Atmospheric scientists have been searching for the sources of about one-third of the major threats, methyl bromide and methyl chloride. New research shows that copper-based compounds in common use generate these compounds when interacting with soil and seawater, with sunlight boosting production by a factor of 10.