Called for a reduction in cfc emissions worldwide.

Montreal

Explanation:

The Montreal Protocol of 1987 had the purpose to make a treaty, agreement, between all the nations in the world in order to stop the CFC emissions in the atmosphere. The main reason for this was to protect the ozone layer and give it chance to recover to its natural levels.

The Montreal Protocol turned out to be a success and a great example that collaboration between all countries in the world is possible, and that it can help the environment, as well as the whole humanity. The CFC emission stopped worldwide, and the ozone layer started to recuperate. Gradually, the ozone holes started to fill in with ozone again, and it is expected somewhere between the years of 2050 and 2070 that the ozone layer will return to its condition of before 1980.