The Montreal Protocol on Substances that Deplete the Ozone Layer

The Montreal Protocol on Substances that Deplete the Ozone Layer is a global agreement to protect the Earth’s ozone layer by phasing out the chemicals that deplete it. This phase-out plan includes both the production and consumption of ozone-depleting substances. The landmark agreement was signed in 1987 and entered into force in 1989.

The parties to the Protocol meet once a year to make decisions aimed at ensuring the successful implementation of the agreement. These include adjusting or amending the Protocol, which has been done six times since its creation. The most recent amendment, the Kigali Amendment, called for the phase-down of hydrofluorocarbons (HFCs) in 2016. These HFCs were used as replacements for a batch of ozone-depleting substances eliminated by the original Montreal Protocol. Although they do not deplete the ozone layer, they are known to be powerful greenhouse gases and, thus, contributors to climate change.

The Montreal Protocol provided a set of practical, actionable tasks that were universally agreed on. The Protocol has successfully met its objectives thus far and continues to safeguard the ozone layer today. Thanks to the collaborative effort of nations around the world, the ozone layer is well on its way to recovery.

Decision XXIII/30: Decimal places to be used by the Secretariat in analysing and presenting hydrochlorofluorocarbon data for 2011 and later years

Recognizing that for the past several years the Secretariat has been following the informal guidance set out in the report of the Eighteenth Meeting of the Parties [6] to round its data reported to the parties to one decimal place,

Acknowledging the low ozone-depletion potential of many Annex C, group I, controlled substances (hydrochlorofluorocarbons),

Taking into consideration the small quantities of hydrochlorofluorocarbons used by a significant number of parties operating under paragraph 1 of Article 5,

Understanding that, as a result of the low ozone-depletion potential of hydrochlorofluorocarbons, rounding to one decimal place could result in the continued use of a substantial amount of those substances,

Wishing to ensure that any change in the number of decimal places used to calculate baselines, consumption and production is forward looking and does not cause changes in previously submitted data,

To direct the Secretariat to use two decimal places when presenting and analysing for compliance hydrochlorofluorocarbon baselines established after the Twenty-Third Meeting of the Parties and annual hydrochlorofluorocarbon data reported under Article 7 for 2011 and later years;

[6] UNEP/OzL.Pro.18/10.