The Montreal Protocol is an international treaty designed to protect the ozone layer by phasing out the production and consumption of ozone-depleting substances, such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). It was agreed upon in 1987 and has been widely regarded as a successful environmental treaty, as it has helped to significantly reduce the depletion of the ozone layer and mitigate the harmful effects of ultraviolet radiation on the environment and human health.
