1974	Sherwood Rowland and Mario Molina (later to share the 1995 Nobel Prize for Chemistry with Paul Critzen) link the emission of chlorofluorocarbons (CFCs) used in industry to the destruction of ozone in the atmosphere.	Dr. Omar El Arini, Chief Officer of the Secretariat from 1991 to 2003, signs the Agreement made between the Québec government and the Multilateral Fund in 2002.
1977	United Nations Environment Programme initiates the World Plan of Action on the Ozone Layer.
1985	Vienna Convention for the Protection of the Ozone Layer establishes principle of international cooperation on ozone destruction, stressing the need to cooperate in research and monitoring, to share information on CFC production and emissions, and to pass control protocols if and when warranted. For the first time, nations agree in principle to tackle a global environmental problem before its effects are clear, or its existence scientifically proven � the first example of the acceptance of the precautionary principle in a major international negotiation.
1985	Ozone hole first detected over the Antarctic.
1987	Montreal Protocol on Substances that Deplete the Ozone Layer ratified. It requires countries to reduce levels of production and consumption of ozone-depleting substances (ODS) according to an agreed schedule.
1989	Helsinki Declaration adopted at the first meeting of the parties to the Protocol includes a commitment to �facilitate the access of developing countries to relevant scientific information, research results and training and to seek to develop appropriate funding mechanisms to facilitate the transfer of technology and replacement of equipment at minimum cost to developing countries�.
1990	Second Meeting of the Parties to the Montreal Protocol, the London Meeting, agrees on the total phase-out of CFCs and halons. The London Meeting also agrees to facilitate the transfer of new ozone-friendly technologies for Article 5 countries and to establish an Interim Multilateral Fund to assist these Parties (developing country Parties whose consumption of ODS is less than the 0.3 kg per person per year specified by Article 5 of the Protocol); it sets the first allocation for the Fund for 1991-93 at US$160 million, with an additional US$80 million to be made available if more developing countries became Parties.
1991	Interim Multilateral Fund established on 1 January with its Secretariat located in Montreal, Canada.
1991	UNDP, UNEP and the World Bank become implementing agencies of the Fund.
1992	UNIDO becomes an Implementing Agency of the Fund.
1992	Copenhagen Amendment adds hydrochlorofluorocarbons (HCFCs), hydrobromofluorocarbons (HBFCs), and methyl bromide to the phase-out schedules and formally creates the Multilateral Fund.
1994	Multilateral Fund established on a permanent basis.
1994	Replenishment of the Fund for 1994-96 set at US$455 million.
1995	Precise control schedules agreed for Article 5 parties, with most substances being scheduled for phase-out by 2010.
1996	Replenishment of the Fund for 1997-99 set at US$466 million.
1997	Adoption of the idea of support for sectoral strategies; two years later US$62 million is agreed to phase out production and consumption of halons in China by 2010.
1997	Montreal Amendment creates a system of licenses for imports and exports of ODS, mainly in order to tackle the growing illegal trade in the substances.
1999	The compliance period begins for Article 5 Parties (developing countries) with the first control measure � a freeze, at the average of 1995-97 levels, of production and consumption of CFCs � starting on 1 July 1999.
1999	Beijing Amendment adds bromochloromethane to the phase-out schedules and extended the controls on HCFCs to production in addition to the revised controls on consumption.
2002	Total phase-out of bromochloromethane in developed and developing countries.
2005	Replenishment. Total budget for the 2006-2008 triennium is US $470 million.
2007	20th Anniversary of the Montreal Protocol on Substances that Deplete the Ozone Layer
2010	Total phase-out of CFCs, halons and carbon tetrachloride in developing countries.
2015	Total phase-out of methyl chloroform and methyl bromide in developing countries.
2030	Total phase-out of HCFCs in developed  and developing* countries.
	*the annual average of 2.5% is restricted to the servicing of refrigeration and air conditioning equipment existing  on 1 January 2030 for the period 2030-2040 and subject to review in 2015.