The international regulation on the ozone layer sprung from a series of events and discoveries (including the hole of the ozone layer over Antarctica) that provided indisputable evidence that chlorofluorocarbon (CFCs) and other ozone depleting substances are destroying the ozone layer, thereby allowing dangerous levels of ultraviolet radiation to reach the earth. Some of the serious consequences of ozone layer depletion involve the increase in skin cancer, eye cataracts, immune system suppression, and damage to plants. Other substances that can damage the ozone layer in addition to CFCs include: Carbon tetrachloride (CT) used as a solvent, cleaner or pesticide, methyl chloroform used widely in the aerospace, electronics and automotive industry, HCFCs that were initially perceived as the perfect substitute for CFCs but are now ozone depleting substances (ODS).
The ozone regulatory regime was launched by the 1985 Vienna Convention. The Vienna Convention was a framework convention that, while it confirmed the will of states do something about ozone depletion, it did not set specific standards for the phasing out and substitution of ozone depleting substances.
The first drastic measures to restore the ozone layer were adopted in 1987 through the Montreal Protocol on the Substances that Deplete the Ozone Layer and its subsequent amendments (London, Copenhagen, Beijing,Kigali)that mandated the phasing out and significant reduction of ozone depleting substances.
The success of the ozone regime that is epitomized in the expectation of recovery of the ozone layer in the coming decades is attributed to the fact that there is indisputable scientific certainty about ozone depletion due to human activities. This indisputable scientific evidence has motivated policymakers to act. For other environmental issues scientists rarely agree and scientific disagreements are often used by states as justification for inaction.