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.

Summary by year of essential use exemptions

Summary 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
Chlorofluorocarbons 13,869.61 13,530.5 11,988.68 9,882.33 8,366.75 6,792.8 7,133.6 7,048.75 7,720 3,321.1 2,039
Halons 352 300 255 160 90            
Carbon tetrachloride               2.05      
1,1,1-trichloroethane (methyl chloroform) 59.7 60.5 60.1 59.6 58.4 58.4          
HBFCs and Bromochloromethane               0.025      
TOTAL 14,281.31 13,891 12,303.78 10,101.93 8,515.15 6,851.2 7,133.6 7,050.825 7,720 3,321.1 2,039

 

Summary 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Chlorofluorocarbons 1,928 937 682 2,488.312 1,262.95 908.49 695.82 532.05 257.61      
Carbon tetrachloride                 80 70 65 65
TOTAL 1,928 937 682 2,488.312 1,262.95 908.49 695.82 532.05 337.61 70 65 65

 

All quantities expressed in metric tonnes.