International Treaties and Cooperation about the Protection of the Stratospheric Ozone Layer
Through the 1970s and the 1980s, the international community became increasingly concerned that ODS would harm the ozone layer. In 1985, the Vienna Convention for the Protection of the Ozone Layer formalized international cooperation on this issue. This cooperation resulted in the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987.
After the Montreal Protocol was signed, new data showed worse-than-expected damage to the ozone layer. In 1992, the Parties to the Protocol decided to alter the terms of the 1987 agreement to end production of halons by 1994 and CFCs by 1996 in developed countries. More information on the phaseout of ODS is found here .
Because of measures taken under the Montreal Protocol, emissions of ODS are falling and the ozone layer is expected to be fully healed near the middle of the 21st century. More information on the current state of the ozone layer is found here
The Montreal Protocol on Substances that Deplete the Ozone Layer
The original Montreal Protocol, signed in 1987, was the first step in international efforts to protect stratospheric ozone. Under the original Montreal Protocol agreement (1987), developed countries were required to begin phasing out CFCs in 1993 and achieve a 20% reduction relative to 1986 consumption levels by 1994 and a 50% reduction by 1998. Additionally, developed countries were required to freeze their production and consumption of halons relative to their 1986 levels. After the Montreal Protocol was signed, new data showed worse-than-expected damage to the ozone layer.
The Parties to the Montreal Protocol have amended the Protocol to enable, among other things, the control of new chemicals and the creation of a financial mechanism to enable developing countries to comply. The Montreal Protocol also includes a unique adjustment provision that enables the Parties to the Protocol to respond quickly to new scientific information and agree to accelerate the reductions required on chemicals already covered by the Protocol. These adjustments are then automatically applicable to all countries that ratified the Protocol. Since that time, the Montreal Protocol has been repeatedly strengthened by both controlling additional ozone-depleting substances (ODS) as well as by moving up the date by which already controlled substances must be phased out. In addition to adjustments and amendments to the Montreal Protocol, the Parties to the Protocol meet annually and take a variety of decisions aimed at enabling effective implementation of this important legal instrument.
Because of measures taken under the Montreal Protocol, emissions of ODS are falling and the ozone layer is expected to be fully healed near the middle of the 21st century. More information on the current state of the ozone layer is found here.
Amendments to the Montreal Protocol
The London Amendment (1990) changed the ODS emission schedule by requiring the complete phaseout of CFCs, halons, and carbon tetrachloride by 2000 in developed countries, and by 2010 in developing countries. Methyl chloroform was also added to the list of controlled ODSs, with phaseout in developed countries targeted in 2005, and in 2015 for developing countries.
The Copenhagen Amendment (1992) significantly accelerated the phaseout of ODSs and incorporated an hydrochlorofluorocarbons (HCFC) phaseout for developed countries, beginning in 2004. Under this agreement, CFCs, halons, carbon tetrachloride, and methyl chloroform were targeted for complete phaseout in 1996 in developed countries. In addition, methyl bromide consumption of methyl bromide was capped at 1991 levels. More information on the phaseout of ODS is found here .
The Montreal Amendment (1997) included the phaseout of HCFCs in developing countries, as well as the phaseout of methyl bromide in developed and developing countries in 2005 and 2015, respectively.
The Beijing Amendment (1999) included tightened controls on the production and trade of HCFCs. Bromochloromethane was also added to the list of controlled substances with phaseout targeted for 2004.
The Kigali Amendment (2016)extended controls to phase down the production and consumption of hydrofluorocarbons (HFCs) because these substances were adopted by industries in moving away from ozone-depleting substances and they are potent greenhouse gases damaging to the earth’s climate.
The Vienna Convention
Adopted in 1985, The Vienna Convention for the Protection of the Ozone Layer is the precursor to the Montreal Protocol. The Vienna Convention is often called a framework convention, because it served as a framework for efforts to protect the globe’s ozone layer. The Vienna Convention did not require countries to take concrete actions to control ozone depleting substances. Instead, in accordance with the provisions of the Convention, the countries of the world agreed the Montreal Protocol on Substances that Deplete the Ozone Layer under the Convention, to advance that goal.
United Nations Environment Programme (UNEP) Ozone Secretariat
U.S. agencies, including EPA, work with the UNEP Ozone Secretariat to implement the Montreal Protocol.
The Parties the Montreal Protocol have advisory bodies called Assessment Panels. The Assessment Panels are responsible for issuing regular reports on progress on implementing the phaseout of ozone-depleting substances, including assessments of alternatives and emissions reduction.
TEAP – The Technology and Economic Assessment Panel (TEAP) provides technical information related to the alternative technologies that have been investigated and employed to make it possible to virtually eliminate use of Ozone Depleting Substances (such as CFCs and Halons), that harm the ozone layer.
SAP - The Scientific Assessment Panel (SAP) assesses the status of the depletion of the ozone layer and relevant atmospheric science issues.
EEAP - The Environmental Effects Assessment Panel (EEAP) assesses the various effects of ozone layer depletion
UNEP’s Division of Technology, Industry, and Economics OzonAction Programme provides industry, government, and other stakeholders in developing countries with information exchange services, training, and networking. In addition to these core clearinghouse services, the Programme also provides assistance with Country Programmes and Institutional Strengthening projects.