Last edited 17 Oct 2016

Montreal Protocol on Substances that Deplete the Ozone Layer

The Montreal Protocol on Substances that Deplete the Ozone Layer (the Montreal Protocol) was agreed on 16 September 1987 and came into effect on 1 January 1989. It came after a series of rigorous meetings and crucial negotiations at the Headquarters of the International Civil Aviation Organisation in Montreal, Quebec, in Canada and was ratified by all 196 United Nations members.

It was developed in order to reduce the production of ozone-depleting substances. Its framework was defined by the Vienna Convention for the Protection of the Ozone Layer, in 1985.

The emissions of ozone-depleting substances increased in the middle to late 20th century, peaking in the late 1980s and contributing to the formation of the 'ozone hole' over the Antarctic. This was linked to the increased use of chemicals such as chlorofluorocarbons (CFCs) in refrigeration, industrial cleaning, foam blowing and air conditioning.

The high-altitude stratospheric ozone layer acts as a shield in the atmosphere, protecting life from harmful ultraviolet (UV) radiation emitted by the sun. Scientific evidence shows that certain compounds can cause considerable damage to and weakening of the earth’s ozone layer, leading to increases in the incidence of skin cancer and cataracts, as well as having an adverse effect on crops, plants and ocean plankton.

Ozone is destroyed by chlorine and bromine atoms within ozone-depleting substances, also referred to as 'halogen source gases', including:

  • Chlorofluorocarbons (CFCs).
  • Hydrochlorofluorcarbons (HCFCs).
  • Halons.
  • Methyl chloroform.
  • Carbon tetrachloride (the main precursor of CFCs).
  • Methyl bromide.

The Montreal Protocol was a landmark international agreement that can lay claim to a series of major achievements, including:

  • Being the first treaty to achieve universal participation.
  • The production and consumption of the majority of harmful ozone-depleting chemicals has been successfully phased out, in both developed and developing countries. Over 98% of the consumption of all ozone-depleting substances has been eliminated.
  • It is anticipated that in the late 21st century, the ozone layer will have substantially recovered. This success has largely been attributed to the development of ‘ozone friendly’ substitutes for ozone-depleting substances.
  • The Multilateral Fund, which was set up in 1991 has approved industrial conversion, technical assistance, training and capacity-building, worth over £2 billion.
  • The Montreal Protocol is also one of the prime global contributors to the fight against climate change. This is because ozone-depleting substances tend also to be powerful greenhouse gases.

In order to meet the Montreal Protocol obligations, European and UK regulations have been devised.

At the EU level, the regulations are:

  • Regulation (EC) 1005/2009 on substances that deplete the ozone layer.
  • Amended by Commission Regulation 744/2010 on the critical uses of halons.

At the UK level, the regulations are:

Since its original agreement, the Montreal Protocol has been amended and adjusted several times.

On 15 October 2016 it was announced that 170 countries in Kigali, Rwanda, had agreed that all HFC’s should be phased out through an amendment to the Montreal Protocol. See HFC phase out for more information.

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