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Max Planck Encyclopedia of Public International Law [MPEPIL]

Ozone Layer, International Protection

K Madhava Sarma, Stephen O Andersen, Durwood Zaelke, Kristen N Taddonio

Sustainable development — Climate change

Published under the auspices of the Max Planck Foundation for International Peace and the Rule of Law under the direction of Rüdiger Wolfrum.

A.  Introduction and Background

The 1987 Montreal Protocol on Substances that Deplete the Ozone Layer (‘MP’), and its underlying framework convention the 1985 Vienna Convention on the Protection of the Ozone Layer (‘VCPOL’), seek to protect the ozone layer in the stratosphere, located 10 to 15 kilometres above the earth (see also Atmosphere, International Protection; Framework Agreements). The ozone layer protects the earth from excessive ultraviolet (‘UV’) radiation that endangers human health by increasing skin cancer and cataracts, and suppressing the immune system, and that also damages agricultural production, natural ecosystems, and the built environment. In 1970, Paul Crutzen of the Netherlands postulated that emissions of nitrogen oxides could reach and catalytically deplete the thin layer of stratospheric ozone. In 1974, Mario Molina of Mexico and Sherwood Roland of the United States warned that emissions of man-made halocarbons (‘Ozone Depleting Substances’ or ‘ODS’), which also have high global warming potentials, constitute the main threat to the ozone layer. Crutzen, Molina, and Rowland received the Nobel Prize for Chemistry in 1995 for their ground-breaking science. Over time, the ODSs were proven to be the main cause of stratospheric ozone depletion.

ODSs are inert, long-lived substances, and were considered ‘wonder chemicals’ when invented in 1928. Their use rapidly expanded to many industries and processes, such as aerosol cosmetic products, refrigeration, air conditioning, foams, electronics, and metal cleaning, and fire fighting.

The United Nations Environment Programme (UNEP) launched a World Plan of Action on the Ozone Layer in 1977 to study and suggest solutions to the problem (see Biswas Appendix 2), and initiated diplomatic discussions (see Andersen and Madhava Sarma). In the following years, scientists continued to confirm the depletion of the ozone layer. However, the diplomatic negotiations proceeded slowly, with some governments and companies that manufactured ODSs arguing that the connection with ozone depletion was only a theory and had not been observed.

Finally, in 1985, 34 governments agreed to the VCPOL. The discovery, also in 1985, of the complete destruction of the ozone layer above Antarctica during the Antarctic spring from August to November every year (the ‘ozone hole’) created a world-wide sensation. After more negotiations, the governments agreed to the MP in 1987.

The VCPOL and the MP build upon general international legal principles (General International Law [Principles, Rules and Standards]), foremost that a State is responsible for activities under its jurisdiction or control that cause damage to another State, or to areas beyond national control (Hunter Salzman and Zaelke 497–502; State Responsibility).

The ozone protection regime has successfully eliminated more than 96% of the production and consumption of ODSs, putting the ozone layer on the path to recovery to pre-1980 levels by 2050. Globally, this prevented an estimated 19.1 million non-melanoma cancer cases, 1.5 million melanoma cases, 129 million eye cataracts, and 333,500 cancer fatalities over the period 1987–2060. Total costs are estimated at US$224 billion and quantified benefits at US$459 billion (see Environment Canada). In addition, the MP contributed significantly to mitigation of climate change (see Velders Andersen, Daniel Fahey, and McFarland; Climate, International Protection).

B.  1985 Vienna Convention on the Protection of the Ozone Layer

The VCPOL provides a framework for protecting the ozone layer, initiates research and information reporting and exchange, and the adoption of national policies to protect the ozone layer, but it does not require specific reductions of ODS consumption. A conference of States Parties (‘COP’; Art. 6 VCPOL; Conference [Meeting] of States Parties) and a secretariat (Art. 7 VCPOL) were created. Amendments to the VCPOL, or the addition of subsequent protocols, require a three-fourths majority of the parties present and voting at the meeting, and each party also has to ratify the amendments and subsequent protocols (Art. 9 VCPOL). However, the amendment to an annex, or an additional annex, enters into force for all parties without individual ratification, except for a party that within six months from the date of the communication of the adoption by the depositary notifies that it is unable to accept the amendment or annex (Art. 10 (2) (b) VCPOL). The VCPOL allows its protocols to adopt their own procedure for amendment. The parties are to settle disputes through negotiation or mediation, and to notify at ratification that they accept either arbitration, or submission of the dispute to the International Court of Justice (ICJ), or both as compulsory (Art. 11 (3) VCPOL; Environmental Dispute Settlement). If a party does not choose, the dispute shall be submitted to a conciliation commission whose decision is recommendatory. (Art. 11 (4) VCPOL) No reservations to the VCPOL are permitted (Art. 18 VCPOL; Treaties, Multilateral, Reservations to). The VCPOL has therefore successfully fulfilled its role as a framework for addressing the threat to the ozone layer.

C.  1987 Montreal Protocol on Substances that Deplete the Ozone Layer

54 governments adopted the MP by consensus on 16 September 1987, freezing production and consumption levels of eight chlorofluorocarbons (‘CFCs’) and halons, setting a 50% reduction of CFC consumption by 1998, and specifying that the MP would enter into force upon ratification by 11 States Parties representing at least two-thirds of the global ODS production (Tolba and Rummel-Bulska 2007). The MP provided for a periodical review of its control measures after scientific and technical assessments (Art. 6 MP). No reservations are permitted. The Protocol entered into force on 1 January 1989; it has since been revised several times, with the last adjustment in 2007 and last amendment in 1999 (all MP citations in this text are to the latest version of the Protocol).

1.  Objective

The objective of the MP is to reduce and phase out ODSs throughout the world according to a time schedule on the basis of periodic scientific assessment, taking into account technical and economic feasibility.

2.  Chemicals Covered

10  The MP now covers 96 chemicals. The damage that these chemicals cause to the ozone layer is weighted using a metric called ozone depletion potential (‘ODP’). Many ozone depleting substances are also powerful greenhouse gases. The production or consumption of each group of ODSs is defined as the sum of ODP-weighted production or consumption of ODSs in that group (Art. 3 MP). All ODSs have a phase out schedule, subject to essential or critical use exemptions to be approved by a Meeting of the Parties (‘MOP’).

11  CFCs were used in refrigerators, air conditioners, spray cans, solvents, foams, and other applications. Halons were used primarily in fire protection. Carbon tetrachloride and methyl chloroform were primarily used as solvents. Hydrobromofluorocarbons (‘HBFCs’) were not widely used when the MP was signed, but they were added to the list of controlled substances to prevent any new uses. Hydrochlorofluorocarbons (‘HCFCs’) were developed as the first major replacement for CFCs. While much less destructive than CFCs, HCFCs also contribute to ozone depletion and are potent greenhouse gases. Methyl bromide (CH3Br) is used as a fumigant for high-value crops, pest control, and quarantine treatment of agricultural commodities awaiting export. Bromochloromethane (‘BCM’), an ozone-depleting substance that some companies sought to introduce into the market in 1998, was targeted for immediate phase-out to prevent its use.

12  Although they agreed to it, parties were particularly apprehensive about the total phase-out of halons and of methyl bromide. There are no effective replacements for halons for some applications even now. However, the large quantity of halons available in equipment that could use alternatives was recovered and recycled. As a result, the production of halons was completely halted from 1 January 1994, with one small exception for Halon 2402, used by equipment made in the former Soviet Union and not recycled adequately. This is an astonishing result, given that phase-out of halons was considered impossible. Methyl bromide also caused some problems. Alternatives to methyl bromide often had to be matched to particular agro-climatic conditions. Additionally, some developed countries sided with farm interests that feared that costlier alternatives to methyl bromide may make them less competitive to farmers in developing countries, who could continue to use the cheaper methyl bromide during the grace period of ten years allowed to them. Parties annually approve exemptions for ‘critical’ uses. However, with experience, such exemptions are rapidly becoming less frequent.

3.  Adjustments and Amendments

13  The MP has a simplified procedure for adjustments of the ODP of ODSs and for further adjustments and reductions in production and consumption of ODSs (Art. 2 (9) MP). The adjustments must be approved by two-thirds of the States Parties, with a simple majority of both the Art. 5 Parties, ie developing countries with annual per capita consumption less than the quantity specified in Art. 5 MP, and the non-Art. 5 Parties. The adjustments are binding on all parties. The second (London 1990), fourth (Copenhagen 1992), seventh (Vienna 1995), ninth (Montreal 1997), eleventh (Beijing 1999), and nineteenth (Montreal 2007) MOP adopted such adjustments.

14  An ‘amendment’ that requires ratification by each party is necessary if new substances are included or other articles of the MP are changed (Art. 2 (10) MP). Each of the amendments was a single package, even though each dealt with more than one group of controlled substances, or more than one aspect thereof. The second, fourth, ninth, and eleventh MOP to the MP adopted four amendments to the MP. No country can ratify the MP without ratifying the VCPOL. Also, before ratifying a later amendment, a State Party has to ratify all the earlier amendments to the MP. Each State Party takes its own time to ratify, depending on its laws. As of 13 April 2009, the VCOPL and the MP have been ratified by 193 States and the European Union (European Community and Union, Party to International Agreements), and the London, Copenhagen, Montreal, and Beijing Amendments by 191, 186, 172, and 153 Parties respectively. There has been no case of any party refusing to ratify an amendment.

4.  Control of Trade

15  To discourage non-parties from ‘free riding’, and to discourage parties from shifting production to non-parties, the MP prohibits trade in ODS with non-parties, including trade in products containing or made with ODSs (Art. 4 MP; Trade and Environment). Art. 4A MP prohibits trade with parties that do not comply with the controls. Art. 4B MP mandates that all parties implement a licensing system for import and export of ODSs.

5.  Assessment Panels

16  The first MOP in 1989 established scientific, environmental effects technical and economic assessment panels. Later, the technical and economic assessment panels were merged into a Technology and Economic Assessment Panel (‘TEAP’). The TEAP is assisted by sector wise technical options committees (‘TOCs’). While the members of the panels and co-chairs of the TOCs are appointed by the parties, the co-chairs of panels are free to select the experts to assist them. Governments can nominate experts but cannot insist on their inclusion. The membership is equitable across regions. Their reports are presented to the parties as they are written, without any editing by parties.

6.  Concessions and Assistance for Developing Countries

17  The framers of the MP realized early that ozone depletion is a global problem impacting all. Emissions anywhere in the world would deplete the ozone layer. The developing countries consumed, in 1987, less than 15% of the ODS worldwide and contributed little to the problem of the ozone depletion. However, their share of contribution to the problem would go up with their increasing consumption of ODS. The framers recognized this principle of common but differentiated responsibilities in practice. To attract developing countries, the MP provides a grace period for Art. 5 parties to meet mandated reductions. Art. 10 MP providing for technical assistance and financial assistance did not satisfy developing countries. The new Art. 10 MP, amended in 1990, established a financial mechanism including a multilateral fund (‘MLF’) funded by non-Art. 5 parties to meet all agreed incremental costs of the Art. 5 parties (Art. 10 MP). The 1990 MOP approved an indicative list of incremental costs (United Nations Environment Programme ‘Report of the Second Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ocean Layer’ [29 June 1990] UNEP/Ozl.Pro/2/3 Appendix 1). Art. 5 MP was amended to recognize that the implementation of the control measures by Art. 5 parties will depend on effective implementation of Arts 10 and 10A MP. If an Art. 5 party felt that it was unable to implement the control measures due to inadequate implementation of Arts 10 and 10A MP, it could so report to an MOP and any proceedings under the non-compliance procedure would not be invoked against that party until a MOP considered the issue.

18  Every party is mandated to take every practicable step to transfer the best available substitutes and technologies to developing country States Parties (Art. 10A MP; Technology Transfer).

7.  Key Features of the Financial Mechanism

19  The MLF is contributed to by the non-Art. 5 parties on the basis of the UN scale of assessments. The MLF is replenished once every three years through a decision of the MOP. The MOP decides the amount, after considering an expert assessment by the TEAP, on the funds needed for enabling compliance. The MLF has been replenished seven times. As of July 2008, the contributions made to the MLF totalled over US$2.4 billion. The MLF is administered by an executive committee consisting of seven members from the Art. 5 parties and seven from non-Art. 5 parties, elected annually by the MOPs. The chairmanship and vice-chairmanship rotate between the two groups annually. The decisions of both the MOPs and the executive committee are made by consensus and, if a consensus cannot be achieved, though a double majority in each group. Any bilateral contribution by a country to meet the agreed incremental costs was counted as a contribution only up to 20% of the contributions due from that country and such bilateral programmes require the approval of the executive committee.

8.  Global Environment Facility: Financing Countries with Economies in Transition

20  In the beginning of the 1990s, the then Union of Soviet Socialist Republics (USSR) broke up into 20 independent republics. All the republics and also the countries of Eastern Europe gradually gave up communism to become market oriented economies and experienced great social and economic upheavals, from which they ultimately recovered. None of these countries in transition—except Albania, Romania, and Yugoslavia—were classified as ‘developing countries’ and hence they were obliged to phase out most ODSs by 1996. They were in no position to do so. The Global Environment Facility (GEF), that was established in 1991 by the governments to finance the incremental costs of eligible countries for global environmental problems, including ozone depletion, provided financing to the countries with economies in transition (‘CEIT’) to implement the control measures of the MP. As the MLF was established for financing Art. 5 parties, the GEF did not finance any Art. 5 parties.

9.  Institutional Setting

21  The MP established the MOP (Art. 11 MP), the secretariat (Art. 12 MP), and the executive committee to administer the MLF (Art. 10 (5) MP). Meetings of an open-ended working group of the parties prepare the annual MOP. An implementation committee of 10 elected parties assists the MOP to consider and make recommendations on issues relating to non-compliance (Art. 8 MP; Environmental Treaty Bodies).

10.  Implementation Roles of Stakeholders

(a)  International and Bilateral Agencies

22  The World Meteorological Organization (WMO) in co-operation with NOAA, NASA, and UNEP manages meetings and publishes the reports of the MP Scientific Assessment Panel (‘SAP’) and of the once-in-three-years meetings of the ozone research managers of the parties to the MP. The UNEP alerted the governments to the danger of ozone depletion in 1975 and continued to play a significant role in the implementation of the VCPOL and the MP. The UNEP, under the steward ship of its Executive Director, Mostafa Tolba (1973–92) forsook the traditional neutral role of the UN organizations and guided the negotiations towards the MP and its steady strengthening thereafter. The role of the UNEP as an implementing agency of the MLF is to create awareness and provide information on all issues of the MP. The United Nations Development Programme (UNDP), the United Nations Industrial Development Organization (UNIDO), and the World Bank implemented the MLF investment projects to convert industries and processes to ozone-safe technologies (see also World Bank Group). The successful implementation of the MP by the Art. 5 parties is, in a large measure, due to the effective functioning of these agencies.

23  The World Customs Organization (WCO) was the authority that harmonized the commodity numbering system for monitoring trade in ODSs. The World Health Organization (WHO) is the source of information on the adverse effects of methyl bromide. The Food and Agriculture Organization of the United Nations (FAO) is the source of information about methyl bromide and its alternatives. Many bilateral aid agencies used part of their contribution to the MLF for bilateral assistance.

(b)  Industry

24  Industry has turned from sceptics to partners in international ozone layer protection. Three ways that industry has been critical to the success of the ozone layer protection is by serving on international technology assessment panels, by developing and promoting alternatives to ozone-depleting substances, and by serving as informal monitors for compliance with the MP. 47% of the members of the TEAP and its technical options committees were from the industrial sector (Andersen Pizano and Taddonio; United Nations Environment Programme ‘Report of the Task Force on Continuing TEAP Legacy’). Industry associations helped to accelerate the development and introduction of alternatives to CFCs. Three such examples that helped to speed the introduction of alternatives were the Alternative Fluorocarbon Environmental Acceptability Study (‘AFEAS’), the Programme for Alternative Fluorocarbon Toxicity Testing (‘PAFT’), and the Industrial Conference on Ozone Layer Protection (‘ICOLP’). The chemical industry helped compliance officials by reporting on illegal trade, and provided the public with information on legal and technical risks associated with importing CFCs from suspicious sources (Benedick 274–75).

(c)  NGOs

25  Non-Governmental Organizations (‘NGOs’) played a diverse and important role in ozone layer protection (see also Environment, Role of NGOs). Environmental law organizations, such as the Natural Resources Defense Council, intervened in legislative, administrative, and judicial processes in the US to control the use and marketing of ODS products. Environmental policy and research organizations such as the Center for Science and Environment, India and the World Resources Institute, US concentrated on policy analysis and communication. Greenpeace, Friends of the Earth, Consumer Unity and Trust Society, and other large environmental organizations launched campaigns demanding action. The Pesticide Action Network’s worked on methyl bromide alternatives, the Environmental Investigation Agency’s focused on illegal trade helped implementation, and the Center for International Environmental Law organized technical co-operation workshops between the USSR and private enterprises from Europe, Japan, and North America.

(d)  Governments

26  National governments used many strategies to promote implementation. Customs codes and permits for production, import, and export of ODSs, product bans and use controls, sector phase-out schedules, refrigerant service procedures that included venting prohibition, recovery/recycling, service training and certification, and sale of ODSs only to certified technicians working in shops, ODSs recycling, and manufacturing containment played an important role. Economic incentives and disincentives in the market, such as government procurement preference for ODSs-free products and ODSs taxes, fees, and trading and auctioning schemes were introduced. Public awareness and consumer empowerment, including educational campaigns, labelling requirements (official, third-party, or self-certification), industry education, review and approval of ODSs alternatives, equipment standards, establishment of halon banks, and research and development were other key government activities. Quasi-governmental activities, such as standard associations and health and medical registration, voluntary government/industry programmes, including company pledges and industry/government/NGO partnerships also played a role.

11.  Compliance Control Mechanism

(a)  Reporting of Data

27  Reliable and timely reports by the parties on production and consumption of the ODSs under Art. 7 MP are the basis for monitoring the implementation of the control measures (Environmental Compliance Control). The parties have initially experienced difficulties in collecting and reporting their data. The reporting improved gradually with national licensing systems, regulations, and training assisted by the MLF.

(b)  Non-Compliance Procedure

28  Non-compliance procedures, as approved by the MOP, apply without prejudice to the procedure laid down in Art. 11 VCPOL (United Nations Environment Programme ‘Report of the Tenth Meeting of Parties to the Montreal Protocol on Substances that Deplete the Ocean Layer’ [5 December 1998] UNEP/Ozl.Pro 10/9 Annex II). Any party can represent regarding another party’s non-compliance. The secretariat also may bring out any non-compliance during its analysis of data submitted under Art. 7 MP. A party concluding that it is unable to comply fully with its obligations may inform the secretariat of its reasons. No party has so far submitted any representation regarding non-compliance by another. The cases noted so far, with a single exception, are from the secretariat reports on annual data. The exception was in 1994, when the Russian Federation and some Eastern European and former USSR States Parties submitted a statement to the MOP that they might not be able comply with phase-outs. The implementation committee considers each case and makes recommendations to the MOP. It can undertake, upon the invitation of the party concerned, information gathering in the territory of that party for fulfilling the functions of the committee. It functions in co-ordination with the executive committee of the MLF.

(c)  Responses to Non-Compliance

29  The fourth MOP, in 1992, finalized the ‘Indicative list of measures that might be taken by a Meeting of the Parties in respect of non-compliance with the Protocol’ (United Nations Environment Programme ‘Report of the Fourth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ocean Layer’ [25 November 1992] UNEP/OzL.Pro.4/15 Annex V). These measures are as follows: first, appropriate assistance is provided including assistance for the collection and reporting of data, technical assistance, technology transfer and financial assistance, information transfer, and training. If this fails, cautions are issued. Suspension is the final response.

(d)  Experience with the Non-Compliance Procedure

30  The MOP takes a sympathetic view of the problem of non-reporting, with decisions urging the parties to report expeditiously and giving advice on how to improve reporting. In cases of non-compliance with the control measures, the MOP requests the concerned parties to submit benchmarks and annual targets for return to compliance. In a few cases of non-observance of benchmarks States Parties were cautioned that more stringent action would be taken unless the party achieved the benchmarks it promised. So far, there has been only one case of suspension of rights and privileges. In 1995, the MOP took a decision, which, inter-alia, restricted, following non-compliance, the Russian Federation from exporting ODSs to other countries except to the countries of the former Soviet Union (United Nations Environment Programme ‘Report of the Seventh Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ocean Layer’ [27 December 1995] UNEP/Ozl.Pro.7/12 Decision VII/18).

(e)  Record of Compliance

31  Among the 146 non-Art. 5 parties, the countries of the former Soviet Union and Eastern Europe could not comply with the control measures. Almost all returned to compliance with the assistance of the GEF. The only CEIT party noticed for non-compliance by the 16th MOP in 2004 and 17th MOP in 2005 was Azerbaijan (see United Nations Environment Programme ‘Report of the Sixteenth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ocean Layer’ [16 December 2004] UNEP/Ozl.Pro.16/17 Decision XVI/21; United Nations Environment Programme ‘Report of the Seventeenth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ocean Layer’ [25 January 2006] UNEP/Ozl.Pro.17/11 Decision XVII/26). Among the other non-Art. 5 parties, only Greece came to the notice of the 19th MOP for not notifying to the Secretariat that it had obtained a transfer of production rights from the UK, and was cautioned (see United Nations Environment Programme ‘Report of the Nineteenth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer’ [21 September 2007] UNEP/OzL.Pro.19/7 Decision XIX/21).

32  From 2001 (13th MOP) onwards, 30 Art. 5 parties came to notice for non-compliance based on the data submitted. The MOPs noted their non-compliance, and asked them to submit their plan of action and benchmarks to return to compliance; they were also cautioned. No other action was taken against them.

12.  Results of the Montreal Protocol

33  The overall reduction of production and consumption of ODSs has been impressive and beyond the mandate of the MP. The following table shows the progress for some ODSs according to the reports of the year 2007. The consumption of ODSs by non-Art. 5 parties is only for ‘essential uses’ approved by the MOP from time to time. The Art. 5 parties reduced their consumption of CFCs from 164,264 tons in the base period to 12,520 tons in 2007, by more than 92% as against the mandated reduction of 85% by the MP. The halons consumption is down by more than 95%. The world consumption of CFCs and halons is down, from 1.32 million tons in the base period to about 13,000 tons in 2007, by nearly 99%, and methyl bromide consumption from 44,000 tons in the base period to 7250 tons in 2007 ([13 April 2009]).

13.  Significance in Practice and Evaluation

34  The ozone treaty regime has implemented and practiced many innovative principles and mechanisms, including:

  • • The precautionary approach/principle, which states that ‘where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation’ (UN Conference on Environment and Development ‘Rio Declaration on Environment and Development’ [14 June 1992] UN Doc A/CONF. 151/26/Rev 1 vol I, 3, Principle 15; Stockholm Declaration [1972] and Rio Declaration [1992]) has been practiced by the Montreal Protocol.
  • • The principle of common but differentiated responsibilities was aggressively implemented.

  • • Control measures have been updated frequently based on independent expert assessments. The experts of the assessment panels have been drawn from all regions of the world.

  • • All decisions have been taken by consensus, respecting and accommodating any minority views, which has facilitated implementation. In the case of amendments, parties have taken immediate steps for their implementation.

  • • There have been many international partnerships between industry, the military, and NGOs for development and dissemination of alternative technologies.

  • • Simplified procedures have been provided for ‘adjustments’, for stricter controls of chemicals already controlled, and such adjustments are binding to all parties.

  • • Non-compliance procedures emphasized assistance to parties not in compliance, and have been backed up with a provision to suspend the rights and privileges of such parties, and trade measures to address ‘free riders’ and threats that production will shift to non-parties.

35  The MP is widely considered the most effective environmental treaty. The Synthesis Report of the 2006 Assessments of the Scientific Assessment Panel, the Environmental Effects Assessment Panel, and the Technology and Economic Assessment Panel states:

The Montreal Protocol is working. There is clear evidence of a decrease in the atmospheric burden of ozone-depleting substances in the lower atmosphere and in the stratosphere; some early signs of the expected stratospheric ozone recovery are also evident… Assuming continuing compliance with the Protocol, it is estimated that the global ozone levels (60°S-60°N) will recover to the pre-1980 values around 2050 (Synthesis Report of the 2006 Assessments of the Scientific Assessment Panel, the Environmental Effects Assessment Panel and the Technology and Economic Assessment Panel, 3–4).

36  The MP also is the most successful treaty for mitigating climate change so far, having reduced greenhouse gas emissions by a net of 135 billion tons of CO2-equivalent, or 11 billion tons per year, from 1990 to 2010, and delaying climate forcing by 7 to 12 years. This is significantly more than the reduction of 1 billion tons of CO2 equivalent per year mandated by the Kyoto Protocol during its first commitment period from 2008–12. When early voluntary and national measures to reduce ODSs are included (from 1974 onwards), the delay in climate forcing is from 35 to 41 years (Velders Andersen, Daniel Fahey, and McFarland).

37  Many, though not all, features of the MP have been incorporated in other global environmental agreements including the 1992 UN Framework Convention on Climate Change and in its 1997 Kyoto Protocol.

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