Montreal Protocol (1973) and the international agreement signed (1985 & 1987). The treaty is structured around several groups of halogenated hydrocarbons that deplete stratospheric ozone. All of the ozone depleting substances controlled by the Montreal Protocol contain either chlorine or bromine (substances containing only fluorine do not harm the ozone layer). Some ozone-depleting substances (ODSs) are not yet controlled by the Montreal Protocol, including nitrous oxide (N2O) For a table of ozone-depleting substances controlled by the Montreal Protocol see: For each group of ODSs, the treaty provides a timetable on which the production of those substances must be shot out and eventually
The Fourth Protocol (film) The Fourth Protocol (film) The Fourth Protocol is a 1987 British Cold War spy film featuring Michael Caine and Pierce Brosnan, based on the novel "The Fourth Protocol" by Frederick Forsyth. In 1968, an East-West agreement is established to halt nuclear proliferation. One of its clauses, the Fourth Protocol, forbids the non-conventional delivery of a nuclear weapon to a target. MI5 officer John Preston (Michael Caine) breaks into the residence of British government official George Berenson (Anton Rodgers) on New Year's Eve and finds a number of top secret NATO files that should not have been there. He reports his