Vienna Convention and the Montreal Protocol

The objective of the 1985 Vienna Convention is to preserve human health, and to protect the environment from any harmful effects of the depletion of the ozone layer. The objective of the 1987 Montreal Protocol is to preserve the ozone layer through the worldwide control, reduction and ultimately elimination of production and consumption of ozone depleting substances. The latest extension of the Montreal Protocol in 2016 – the Kigali Amendment – regulates hydrofluorocarbons as well. These chemicals are currently in use as a substitute for ozone-depleting substances, but are themselves potent greenhouse gases.

1. The international treaties on the protection of the ozone layer

After the mechanism by which chlorofluorocarbons (CFCs) destroy ozone was proved in the 1970s, and the depletion of the ozone layer was observed in the 1980s, two international treaties to protect the ozone layer were signed under the aegis of the United Nations Environment Programme (UNEP): the Vienna Convention (1985) and the Montreal Protocol (1987). These treaties have since been ratified by all Member States of the United Nations. Their implementation has enabled the production and consumption of ozone depleting substances to be reduced by more than 98% between 1986 and 2016.

The objective of the Vienna Convention is to preserve human health, and to protect the environment from any harmful effects of the depletion of the ozone layer. The Convention encourages research activities, cooperation and the exchange of information between states, and national legislative measures, without however prescribing any concrete measures.

  • Adoption: 1985
  • Entry into force in Switzerland: 22 September 1988

The objective of the Montreal Protocol is to preserve the ozone layer through worldwide control, reduction and ultimately elimination of production and consumption of ozone depleting substances. Since many of the substitute chemicals (HFCs) are potent greenhouse gases with an effect more than a thousand times stronger than CO2 and thus contribute to global warming, the Parties to the Montreal Protocol resolved in October 2016 in Kigali (Rwanda), to extend the Montreal Protocol to HFCs (Kigali Amendment), and to reduce the production and consumption of these chemicals by 85% in the medium term. These provisions will come into force on 1 January 2019.

The Montreal Protocol provides a schedule for the reduction of the substances that it regulates. Deadline extensions have been granted to developing countries, and a multilateral Ozone Fond gives them the financial and technical assistance necessary to implement the Protocol.

  • Adoption of the Protocol: 1987, and of its amendments: London: 1990; Copenhagen: 1992; Montreal: 1997; Beijing: 1999; Kigali, 2016
  • Ratification by Switzerland of the Protocol: 1988 and of its amendments: London: 1992; Copenhagen: 1996; Montreal and Beijing: 2002
  • Worldwide ratification (Montreal Protocol and its first four amendments): 2014

Substances regulated

Industrialised countries

Developing countries

  Elimination of production and consumption

CFCs, carbon tetrachloride









Methyl bromide









  Reduction of production and consumption (% of initial volume)


2036 (15%)

2045 (20%)

2047 (15%)*

*Bahrain, India, Iran, Iraq, Kuwait, Oman, Pakistan, Qatar, Saudi Arabia, United Arab Emirates

2. The multilateral Fund for the implementation of the Montreal Protocol (Ozone Fund) 

The principal aim of the Fund is to support developing countries in their efforts to phase out the use of ozone depleting substances – and from 2019 also HFCs – within the deadlines that have been set.

The Fund finances a variety of projects in developing counties and implements them with the support of the World Bank, the United Nations Development Programme (UNDP), the United Nations Industrial Development Organisation (UNIDO), and the United Nations Environment Programme (UNEP).

The Ozone Fund (Multilateral Fund for the Implementation of the Montreal Protocol) was established in 1990, in London, at the second Meeting of the Parties to the Montreal Protocol.

Between 1991 and the end of 2016, the Ozone Fund provided around US$ 3.45 billion to finance 7677 projects and activities in 145 developing countries. This will lead to a reduction in consumption and production of ozone depleting substances of approx. 468,717 tonnes (calculated in equivalents of CFC11).

Switzerland regards the Ozone Fund as an important means of rapidly achieving the Protocol’s objectives in developing countries. Switzerland considers it very important that the projects supported are not only favourable for the ozone layer, but also favourable for the environment in general.

Switzerland currently contributes about US$ 2 million to the Fund annually (total budget US$ 150 million per year). In 1997/1998 and 2010/2011, Switzerland was a member of the Fund's Executive Committee, the task of which is to develop guidelines and supervise the activities of the Fund. Switzerland will again participate in the Executive Committee in the 2020/2021 period.

Switzerland also supports the implementation of the Montreal Protocol in developing countries directly. For example, Switzerland has been involved in bilateral projects on refrigeration technology in India, Indonesia, Argentina, Chile and Costa Rica.

3. Implementation of the Montreal Protocol as seen in Switzerland

Since it was signed, the Montreal Protocol has generally been implemented successfully. The industries and trades concerned have developed alternative solutions for the substances regulated by the Protocol and most industrialised countries, including Switzerland, have largely been able to respect the commitments agreed. Switzerland adheres to international commitments through the provisions of the Chemical Risk Reduction Ordinance (ORRChem).

The atmospheric concentrations of ozone depleting substances have decreased (with the exception of HCFCs and Halon 1301), and the hole in the ozone layer over the Antarctic seems to have reached its maximum. However, we will still have to wait at least till the middle of the 21st century before the ozone layer returns to its pre-1980 state prior, as ozone depleting substances continue to leak from existing objects, products and wastes, and these substances have a long life-time.

Substitute technologies and products that are not harmful to the environment

Substitution products that are themselves harmful for the environment are still used too often as substitutes for chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). For instance, despite their harmful effects on the climate, and in spite of certain provisions of the Protocol, hydrofluorocarbons (HFCs) have been widely promoted and subsidised in developing countries. Some industrial circles put them forwards as universal substitutes for CFCs and HCFCs, despite their very high greenhouse potential. Therefore, their use contributes to the very global warming that the Paris Agreement within the UNFCCC seeks to avoid.

The objective of the 2016 extension of the Montreal Protocol (Kigali Amendment) should rather push forward products and technologies that are as environmentally compatible as possible, with HFCs only used when no alternatives are available. This rule was made possible only after the development of a new generation of alternative chemicals, hydrofluoroolefins (HFOs), which decompose in the atmosphere within a few days. However, their breakdown product, trifluoroacetic acid (TFA), shows a phytotoxic effect and lasts for an extremely long time in surface waters. From Switzerland’s point of view, therefore, we should concentrate much more on developing technologies that use natural gases such as carbon dioxide or ammonia.

Rapid implementation of the Protocol in developing countries

Now that the provisions of the Protocol have been widely applied in industrialised countries, there is a need to ensure implementation in developing countries. Industrialised countries must support developing countries in introducing substitute products and technologies, with appropriate financial assistance from the Ozone Fund set up by the Protocol For their part, the developing countries must respect their commitments on the implementation of the provisions of the Protocol. Under these conditions, the Protocol has already been successfully implemented.

Last modification 27.09.2018

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