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/13: Potential areas of focus for the 2014 quadrennial reports of the Scientific Assessment Panel, the Environmental Effects Assessment Panel and the Technology and Economic Assessment Panel

  1. To note with appreciation the excellent and highly useful work of the Scientific Assessment Panel, the Environmental Effects Assessment Panel and the Technology and Economic Assessment Panel and their colleagues worldwide in preparing their 2010 assessment reports, including the 2011 synthesis report;
  2. To request the three assessment panels to update their 2010 reports in 2014 and submit them to the Secretariat by 31 December 2014 for consideration by the Open-ended Working Group and by the Twenty-Seventh Meeting of the Parties in 2015;
  3. That for its 2014 report, the Environmental Effects Assessment Panel should consider the most recent scientific information regarding effects on human health and the environment of changes in the ozone layer and in ultraviolet radiation, including:
    1. Effects of ultraviolet radiation reaching the biosphere and how those effects relate to physical, biological and environmental processes;
    2. Adverse effects of ultraviolet radiation on human health, including cancers, eye damage, infectious and other diseases and the beneficial effects of ultraviolet radiation;
    3. Effects on the biodiversity and functioning of ecosystems, including the delivery of ecosystem services such as food production;
    4. Effects of ultraviolet radiation on materials, including materials used in building construction;
    5. Risks to human health and the environment from substances that affect the ozone layer;
  4. That the 2014 report of the Scientific Assessment Panel should include:
    1. Assessment of the state of the ozone layer and its future evolution, including in respect of atmospheric changes from, for example, sudden stratospheric warming or accelerated Brewer‑Dobson circulation;
    2. Evaluation of the Antarctic ozone hole and Arctic winter/spring ozone depletion and the predicted changes in these phenomena, with a particular focus on temperatures in the polar stratosphere;
    3. Evaluation of trends in the concentration in the atmosphere of ozone-depleting substances and their consistency with reported production and consumption of those substances and the likely implications for the state of the ozone layer and the atmosphere;
    4. Assessment of the interaction between the ozone layer and the atmosphere; including:
      1. The effect of polar ozone depletion on tropospheric climate;
      2. The effects of atmosphere-ocean coupling;
    5. Description and interpretation of observed ozone changes and ultraviolet radiation, along with future projections and scenarios for those variables, taking into account among other things the expected impacts to the atmosphere;
    6. Assessment of the effects of ozone-depleting substances and other ozone-relevant substances, if any, with stratospheric influences, and their degradation products, the identification of such substances, their ozone‑depletion potential and other properties;
    7. dentification of any other threats to the ozone layer;
  5. That in its 2014 report the Technology and Economic Assessment Panel should consider the following topics:
    1. Technical progress in all consumption sectors and destruction of ozone-depleting substances;
    2. Accounting for production and consumption for the various applications of ozone‑depleting substances;
    3. Technically and economically feasible alternatives to ozone-depleting substances, in consumption sectors taking into account their overall performance;
    4. Status of banks containing ozone‑depleting substances, including those maintained for essential and critical uses, and the options available for handling them;
    5. Challenges facing parties operating under paragraph 1 of Article 5 of the Montreal Protocol in phasing out remaining ozone-depleting substances such as methyl bromide and maintaining the phase-outs already achieved;