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  • Report by Nature finds that the rate of decline of trichlorofluoromethane (CFC-11) in atmosphere has slowed by approximately 50 per cent since 2012.
  • If emissions continue unabated, they have potential to slow down the recovery of the ozone layer.
  • The Montreal Protocol has reduced the abundance of ozone-depleting substances in the atmosphere and as a result, the ozone layer is healing.

16 May 2018 – New findings from a study released this week in Nature report that emissions of CFC-11, the second most abundant ozone-depleting gas controlled by the Montreal Protocol, have unexpectedly increased in recent years, despite a global ban on production since 2010.

These emissions partially offset gains made by the Montreal Protocol, by slowing the decline of ozone-depleting chlorine concentration in the atmosphere. The increased emissions may stem from new, unreported production of CFC-11.

In response, UN Environment issued the following statement:

While current scientific models show that the ozone layer remains on track to recovery by mid-century, continued increase in global CFC-11 emissions will put that progress at risk. The Scientific Assessment Panel of the Montreal Protocol, which includes the authors of the report, will finalize its quadrennial assessment by the end of the year and we expect these findings to be presented to the parties to the Montreal Protocol, who will carefully review and address them.

It is important to note that these findings also highlight the efficacy of the Montreal Protocol, its institutions and mechanisms, with science at their core. So long as scientists remain vigilant, new production or emission of ozone depleting chemicals will not go unnoticed.

 If these emissions continue unabated, they have the potential to slow down the recovery of the ozone layer, it is therefore, critical that we take stock of this science, identify the causes of these emissions and take necessary action.


About UN Environment Ozone Secretariat:

The Ozone Secretariat is the Secretariat for the Vienna Convention for the Protection of the Ozone Layer and for the Montreal Protocol on Substances that Deplete the Ozone Layer. Based at the UN Environment offices in Nairobi, Kenya, the Secretariat functions in accordance with Article 7 of the Vienna Convention and Article 12 of the Montreal Protocol.

About UN Environment:

UN Environment is the leading global voice on the environment. It provides leadership and encourages partnership in caring for the environment by inspiring, informing, and enabling nations and peoples to improve their quality of life without compromising that of future generations. UN Environment works with governments, the private sector, the civil society and with other UN entities and international organisations across the world.

For more information, please contact:

Keith Weller, Head of News and Media Unit, UN Environment, keith.weller[at]