Montreal protocol, a treaty introduced in 1987 and updated in 1990 and 1992, governs the issues causing ozone layer depletion. It requires the countries to stop producing substances that deplete the ozone layer. The Kyoto protocol aims to reduce the green house gases emissions.
Montreal protocol is more of a forerunner for the Kyoto protocol. A successful treaty, Montreal protocol concentrated on eliminating the ozone layer depleting substances (CHFC). All the countries were mandated to participate from the beginning and offered strong incentives and feedback.
Now, the Kyoto protocol is working on reducing the emissions of the greenhouse gases (which were replacements for CHFC) to control global warming. However, many feel that the scope of Kyoto protocol is not fast enough to cover the world’s need for climate control. Therefore, they want the Montreal protocol (relying on its success) to be brought back to address the issue.