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 amending the Single Convention on Narcotic Drugs Protocol amending the Single Convention on Narcotic Drugs The 1972 Protocol amending the Single Convention on Narcotic Drugs was a protocol that made several changes to the Single Convention on Narcotic Drugs. It highlighted the need for treatment and rehabilitation of drug addicts, instructing parties to take "all practicable measures for the prevention of abuse of psychotropic substances and for the early identification, treatment, education, after-care, rehabilitation, and social reintegration of the persons involved". It also expanded the International Narcotics Control Board from 11 members to 13 members. In addition, the Protocol added Article 21 bis, "Limitation of Production of