Excerpts from Books and Wikipedia
"Ozone depletion and the ozone hole have generated worldwide concern over increased cancer risks and other negative effects. The ozone layer prevents harmful wavelengths of ultraviolet (UVB) light from passing through the Earth's atmosphere. These wavelengths cause skin cancer, sunburn, permanent blindness, and cataracts, which were projected to increase dramatically as a result of thinning ozone, as well as harming plants and animals. These concerns led to the adoption of the Montreal Protocol in 1987, which bans the production of CFCs, halons, and other ozone-depleting chemicals. . . . Recovery is projected to continue over the next century, and the ozone hole is expected to reach pre-1980 levels by around 2075. . . . The Montreal Protocol is considered the most successful international environmental agreement to date." [Wikipedia]