The first signs of human-induced ozone depletion appeared in 1957—30 years earlier than previously thought, an MIT simulation reveals. Surprisingly, this initial damage occurred over the tropics and was driven by carbon tetrachloride, a dry-cleaning solvent, long before CFCs took over.

The first signs of human-induced ozone depletion appeared in 1957—30 years earlier than previously thought, an MIT simulation reveals. Surprisingly, this initial damage occurred over the tropics and was driven by carbon tetrachloride, a dry-cleaning solvent, long before CFCs took over.