The UN Conference of Parties on climate change in the year 2011 was held in :
Montreal Protocol -
Recognising the deleterious affects of ozone depletion, an international conference treaty, known as the Montreal Protocol, was signed at Montreal (Canada).
In 1987 (effective in 1989) to control the emission of ozone depleting substances. Subsequently many more efforts have been made and protocols have laid down definite roadmaps, separately for developed and developing countries, for reducing the emission of CFCs and other ozone depleting chemicals.