What Did The Montreal Protocol Do?

by Jeevan Shemar

The Montreal Protocol on Substances that Deplete the Ozone Layer (1987) [1] is an international treaty [2] that came into effect in 1989 [3]. It aims [4] to protect the ozone layer [5] by regulating the production and consumption of certain chemicals. The Montreal Protocol and (its precursor) the Vienna Convention For The Protection Of The Ozone Layer (1985) [6] became the first [7] treaties to achieve universal participation [8] (meaning that every UN Member States [9] participates in it). The Protocol is widely considered to have succeeded [10] in fulfilling its aim of repairing the ozone layer, and consequently it is judged, by some [11] to be one of the most successful examples of international cooperation in history [12].

Key Provisions:

The Montreal Protocol on Substances that Deplete the Ozone Layer (1987) [13] is an international treaty. [14] The Protocol aims [15] to phase out the use of ozone depleting substances by regulating their production and consumption by parties to it. This is done, mainly, by the setting of deadlines pertaining to the phasing out of ozone depleting substances.

The responsibilities imposed on parties to the Protocol are largely the same, irrespective of whether a party is a developing country [16] (the group of which are commonly called Article 5 Parties [17]) or not. However, the deadlines that apply to these two categories differ, with Article 5 Parties having longer [18] to fulfil their obligations. There are currently 147 [19] Article 5 Parties.

Key provisions [20] in the Montreal Protocol include: control measures [21] regulating the use of ozone depleting substances (Article 2) [22] , the calculation of the level of use of ozone depleting substances (Article 3) [23], regulations pertaining to the trading of controlled substances with non-Parties (Article 4) [24], provisions pertaining to the situation of developing countries (Article 5) [25], the reporting of data to the administrative office for the Protocol — the Ozone Secretariat [26] — (Article 7) [27], procedures and institutional mechanisms for determining non-compliance with the Protocol (Article 8) [28], the sharing of technical [29] and financial cooperation between Article 5 Parties and others (Article 10) [30].

The substances deemed to be controlled substances [31] by the Protocol include CFCs (Annex A [32], Annex B [33]), HCFCs (Annex C [34]), HFCs (Annex F [35]).

The Montreal Protocol In Practice:

The Meeting of the Parties [36] is the governing body of the Montreal Protocol. The Meeting convenes annually [37] in order to determine measures that can be taken to ensure that the Protocol is successfully implemented. In the past, this has involved amending the Protocol in response to scientific, technological and economic developments. Several amendments [38] have been made to the Protocol.

Through Article 10, the Multilateral Fund for the Implementation of the Montreal Protocol [39] was established in 1991. The Fund is intended [40] to assist Article 5 Parties to be able to comply with the control measures provided in Article 2. It is managed by the Executive Committee [41] which reports annually to the Meeting of the Parties. Since its creation, the Fund has contributed [42] to many projects in order to support Article 5 Parties in meeting their obligations under the Protocol. 

In order to fulfil their obligations under the Protocol, parties were phasing out their use of CFCs. This often involved replacing them with hydrochlorofluorocarbons [43] (HCFCs). HCFCs are chemical compounds used [44] in (amongst other things) refrigerators and air-conditioning units. While HCFCs are less damaging to the ozone layer than CFCs, they are still ozone depleting substances — working in a similar manner to that of CFCs. In addition to increasing the risk of harmful UV radiation reaching Earth, HCFCs contribute to global warming [45].

As a result, in 2007 [46], the Meeting of the Parties decided to accelerate the phasing out of HCFCs. This meant that [47] Article 5 Parties (with assistance from the Multilateral Fund) should have completely phased-out HCFCs by 2030 and that other countries should have totally phased-out the production and consumption of HCFCs by 2020.

In order to support the phasing out of HCFCs, hydrofluorocarbons [48] (HFCs) were used instead of HCFCs. HFCs are not ozone depleting substances. However, they are greenhouse gases [49] which means that their emission contributes to global warming [50].

Owing to the damaging effects [51] of HFC emissions on the environment, the Kigali Amendment [52] was signed in Rwanda in 2016. It is the most recent amendment to the Protocol: having come into effect in 2019 [53]. By amending the Montreal Protocol, it aimed [54] to reduce the use of HFCs by providing that their production and consumption by should be reduced by at least 80% by the late 2040s [55].


1 https://www.britannica.com/event/Montreal-Protocol

2 https://www.britannica.com/topic/treaty

3 https://treaties.un.org/Pages/ViewDetails.aspx?src=IND&mtdsg_no=XXVII-2-a&chapter=27&clang=_en

4 https://www.environment.gov.au/protection/ozone/montreal-protocol

5 https://www.nationalgeographic.org/encyclopedia/ozone-layer/

6 https://www.britannica.com/topic/Vienna-Convention-for-the-Protection-of-the-Ozone-Layer

7 https://www.unenvironment.org/news-and-stories/press-release/kigali-amendment-hits-milestone-100th-ratification-boosting-climate

8 https://treaties.un.org/pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XXVII-2-a&chapter=27&lang=en

9 https://www.un.org/en/member-states/

10 https://www.unenvironment.org/news-and-stories/story/thirty-years-what-montreal-protocol-doing-protect-ozone1

11 https://www.unenvironment.org/news-and-stories/story/montreal-protocol-triumph-treaty

12 https://theconversation.com/saving-the-ozone-layer-why-the-montreal-protocol-worked-9249

13 https://ozone.unep.org/treaties/montreal-protocol

14 https://law.duke.edu/ilrt/treaties_2.htm

15 https://www.centreforpublicimpact.org/case-study/the-montreal-protocol/

16 https://ozone.unep.org/treaties/montreal-protocol/articles/article-5-special-situation-developing-countries

17 https://ozone.unep.org/classification-parties

18 https://ozone.unep.org/treaties/montreal-protocol/articles/article-5-special-situation-developing-countries

19 https://nou.gov.pk/montreal-protocol/article-5-parties/

20 https://ozone.unep.org/treaties/montreal-protocol/montreal-protocol-substances-deplete-ozone-layer

21 https://ozone.unep.org/treaties/montreal-protocol/summary-control-measures-under-montreal-protocol

22 https://ozone.unep.org/treaties/montreal-protocol/articles/article-2-control-measures

23 https://ozone.unep.org/treaties/montreal-protocol/articles/article-3-calculation-control-levels

24 https://ozone.unep.org/treaties/montreal-protocol/articles/article-4-control-trade-non-parties

25 https://ozone.unep.org/treaties/montreal-protocol/articles/article-5-special-situation-developing-countries

26 https://ozone.unep.org/about

27 https://ozone.unep.org/treaties/montreal-protocol/articles/article-7-reporting-data

28 https://ozone.unep.org/treaties/montreal-protocol/articles/article-8-non-compliance

29 https://ozone.unep.org/treaties/articles/article-10-technical-assistance

30 https://ozone.unep.org/treaties/montreal-protocol/articles/article-10-financial-mechanism

31 https://ozone.unep.org/treaties/montreal-protocol/summary-control-measures-under-montreal-protocol

32 https://ozone.unep.org/treaties/montreal-protocol/articles/annex-controlled-substances

33 https://ozone.unep.org/treaties/montreal-protocol/articles/annex-b-controlled-substances

34 https://ozone.unep.org/treaties/montreal-protocol/articles/annex-c-controlled-substances

35 https://ozone.unep.org/treaties/montreal-protocol/articles/annex-f-controlled-substances

36 https://ozone.unep.org/meetings?field_date_range_end_value%5Bmin%5D=1980-01-01&field_date_range_end_value%5Bmax%5D=2021-12-31&field_meeting_type_value%5BMOP%5D=MOP&combine=

37 https://www.climate-diplomacy.org/events/joint-12th-meeting-conference-parties-vienna-convention-and-32nd-meeting-parties-montreal

38 https://ozone.unep.org/treaties/montreal-protocol/amendments

39 http://www.multilateralfund.org/aboutMLF/default.aspx

40 http://www.multilateralfund.org/Our%20Work/default.aspx

41 http://www.multilateralfund.org/aboutMLF/executivecommittee/default.aspx

42 https://sdg.iisd.org/news/montreal-protocol-multilateral-fund-approves-over-us2-7-million-for-national-projects/

43 https://www.esrl.noaa.gov/gmd/hats/about/hcfc.html

44 https://www.unenvironment.org/ozonaction/resources/factsheet/safe-use-hcfc-alternatives-refrigeration-and-air-conditioning-flammable

45 https://www.pca.state.mn.us/air/chlorofluorocarbons-cfcs-and-hydrofluorocarbons-hfcs

46 https://ozone.unep.org/treaties/montreal-protocol/meetings/nineteenth-meeting-parties

47 https://ozone.unep.org/treaties/montreal-protocol/meetings/nineteenth-meeting-parties/decisions/decision-xix6-adjustments-montreal-protocol-regard-annex-c-group-i-substances

48 https://www.britannica.com/science/hydrofluorocarbon

49 https://www.britannica.com/science/greenhouse-gas

50 https://www.epa.gov/snap/reducing-hydrofluorocarbon-hfc-use-and-emissions-federal-sector-through-snap

51 https://www.ccacoalition.org/en/slcps/hydrofluorocarbons-hfc

52 https://treaties.un.org/Pages/ViewDetails.aspx?src=IND&mtdsg_no=XXVII-2-f&chapter=27&clang=_en

53 https://ozone.unep.org/kigali-amendment-implementation-begins 

54 https://sdg.iisd.org/news/kigali-amendment-enters-into-force-bringing-promise-of-reduced-global-warming/  

Categories Key Terms and Agreements

Tell us what you think!

This site uses Akismet to reduce spam. Learn how your comment data is processed.