International Day for the Preservation of the Ozone Layer of the hole in the ozone layer was observed 30 years after the protocol was signed. Due to the nature of the gases responsible for ozone depletion their chemical effects are expected to continue for between 50 to 100 years. International Day for the Preservation of the Ozone Layer September 16 was designated by the United Nations General Assembly as the International Day for the Preservation of the Ozone Layer. This designation had been made on December 19, 2000, in commemoration of the date, in 1987, on which nations signed the Montreal Protocol on Substances that Deplete the Ozone Layer.
Protocol (politics) Discrimination against Women is supplemented by an Optional Protocol. Protocol (politics) Protocol can mean any logbook or other artifact (forged or authentic) of a political meeting between persons from different nations. The most notorious example of a forged logbook is "The Protocols of the Elders of Zion". In international law, a treaty that supplements or adds to a pre-existing treaty is often given a name that includes "Protocol" in its title. For example, the Kyoto Protocol was supplemental to the United Nations Framework Convention on Climate Change; Protocol I, Protocol II, and Protocol III supplement the 1949 Geneva Conventions; and