Montreal Protocol
The Montreal Protocol on Substances that Deplete the Ozone Layer, also known simply as the Montreal Protocol, is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. Open for signature on 16 September 1987, it was made pursuant to the 1985 Vienna Convention for the Protection of the Ozone Layer, which established the framework for international cooperation in addressing ozone depletion. The Montreal Protocol entered into force on 1 January 1989, and has since undergone nine revisions, in 1990 (London), 1991 (Nairobi), 1992 (Copenhagen), 1993 (Bangkok), 1995 (Vienna), 1997 (Montreal), 1998 (Australia), 1999 (Beijing) and 2016 (Kigali).