In 1985 the Vienna Convention established mechanisms for international co-operation in research into the ozone layer and the effects of ozone depleting chemicals (ODCs). 1985 also marked the first discovery of the Antarctic ozone hole. On the basis of the Vienna Convention, the Montreal Protocol on Substances that Deplete the Ozone Layer was negotiated and signed by 24 countries and by the European Economic Community in September 1987. The Protocol called for the Parties to phase down the use of CFCs, halons and other man-made ODCs.
The Montreal Protocol represented a landmark in the international environmentalist movement. For the first time whole countries were legally bound to reducing and eventually phasing out altogether the use of CFCs and other ODCs. Failure to comply was accompanied by stiff penalties. The original Protocol aimed to decrease the use of chemical compounds destructive to ozone in the stratosphere by 50% by the year 1999. The Protocol was supplemented by agreements made in London in 1990 and in Copenhagen in 1992, where the same countries promised to stop using CFCs and most of the other chemical compounds destructive to ozone by the end of 1995. Fortunately, it has been fairly easy to develop and introduce compounds and methods to replace CFC compounds.
In order to deal with the special difficulties experienced by developing countries it was agreed that they would be given an extended period of grace, so long as their use of CFCs did not grow significantly. China and India, for example, are strongly increasing the use of air conditioning and cooling devices. Using CFC compounds in these devices would be cheaper than using replacement compounds harmless to ozone. An international fund was therefore established to help these countries introduce new and more environmentally friendly technologies and chemicals. The depletion of the ozone layer is a worldwide problem which does not respect the frontiers between different countries. It can only be affected through determined international co-operation.
Montreal Protocol (1987)
CFCs (11, 12, 113, 114, 115): Phase down 1986 levels by 20% by 1994; 50% by 1999.
London Amendment (1990)
CFCs 13, 111, 112, 211, 212, 213, 214, 215, 216, 217: Phase down 1989 levels 20% by 1993; 85% by 1997; 100% by 2000.
Halons (1211, 1301, 2402): Phase down 1986 levels 50% by 1995; 100% by 2000.
Carbon Tetrachloride: Phase down 1989 levels 85% by 1995; 100% by 2000.
Copenhagen Amendment (1992)
CFCs: phase out by 1995
Halons: phase out by 1993
Carbon Tetrachloride: phase out by 1995
HCFCs: phase down 1989 levels 35% by 2004; 90% by 2019; 100% by 2029.
The Montreal Protocol has been further adjusted in Vienna (1995), Montreal (1997) and most recently in Beijing (1999). The Beijing Amendment (1999) has introduced a freezing of HCFC production by 2003.