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
Canada and the Kyoto Protocol of compliance has been estimated 20 times lower. States for which the emissions are not covered by the Kyoto Protocol (the US and China) have the largest emissions, being responsible for 41% of the Kyoto Protocol. China's emissions increased by over 200% from 1990 to 2009. Canadian Council of Chief Executives VP John Dillon argued (2011-11-22) that a further extension of Kyoto would not be effective as many countries, not just Canada, were not on track to meet their 1997 Kyoto commitments to reduce emissions. He called for a comprehensive, long-term global agreement that includes major emitters like the US,