Solutions to prevent depletion of the ozone layer involve banning the use of chemicals that cause ozone depletion, such as chlorofluorocarbons and hydrofluorocarbons. National laws and international treaties help accelerate the control of ozone-depleting substances.
Ozone molecules in the atmosphere absorb harmful radiation, especially ultraviolet light called UVB, which causes cataracts and skin cancer and also damages marine life and crops. Although CFCs were used for many years in solvents, refrigerants and foams, researchers in the 1970s found that the chlorine in CFCs breaks down ozone at the rate of over 100,000 ozone molecules destroyed for each chlorine atom released. This causes the ozone to be destroyed faster than it can be naturally recreated.
HCFCs also destroy ozone, but at a lesser rate. Other chemicals that damage the ozone layer include solvents with methyl chloroform, an industrial chemical called carbon tetrachloride, fire extinguishing agents called halons and a soil fumigant called methyl bromide. The only way to heal the ozone layer is to stop using these substances so that the ozone can naturally regenerate.
The United States and other countries banned the use of CFCs in the 1970s. The Vienna Convention of 1985 and the Montreal Protocol of 1987 further consolidated international resolve on the issue. Since these measures, the phase-out rate of ozone-depleting substances has been revised several times to accelerate the recovery of the ozone layer.