When was the Montreal Protocol signed by 23 countries, including the USA?

The Montreal Protocol was signed on September 16, 1987, by 23 countries, including the United States. This international treaty was established to protect the ozone layer by phasing out the production and consumption of substances that deplete it, such as chlorofluorocarbons (CFCs) and other ozone-depleting chemicals. The protocol is considered a significant achievement in environmental diplomacy, as it brought together countries around the world to address a global concern. The adoption of the Montreal Protocol marked a critical step in efforts to safeguard the ozone layer and highlighted the global commitment to environmental protection.