Which international treaty/agreement negotiated in 1987 specifically aims to protect the ozone layer by phasing out ozone-depleting substances?
The Montreal Protocol on Substances that Deplete the Ozone Layer is an international treaty designed in 1987. It successfully orchestrated global phase-out of harmful chlorofluorocarbons (CFCs). [Memory Trick: Protect the ozone shell to prevent the Earth from getting warm and 'Melting'= 'Montreal' Protocol.]