The Montreal Protocol

Source: Ozone cfc trends | WikiMedia

The Montreal Protocol is an international treaty that most developed countries signed in 1987. The goal of the treaty was to phase out production of materials that released chlorofluorocarbons, or CFC’s, into the atmosphere. These CFC’s are the major contributor to stratospheric ozone depletion. As you can see from the graph, this treaty has drastically reduced ozone-depleting gas worldwide.