Montreal Protocol

The Montreal Protocol on Substances that Deplete the Ozone Layer is an international treaty that is designed to protect the ozone layer. The ozone layer is, in a word, the Earth's “sunscreen” that absorbs ultraviolet radiation, thus allowing life to exist on land. The Montreal Protocol was designed to phase out ozone-depleting substances (ODSs)—substances that had been created for various purposes, most famously for use in aerosols, refrigeration, and other forms of air-conditioning. The treaty was signed in 1987 and entered into force in 1989. Since then, the treaty has been amended four times: the London Amendment (adopted in 1990, entered into force in 1992), the Copenhagen Amendment (adopted in 1992, entered into force in 1994), the Montreal Amendment (adopted in 1997, entered into force ...