Montreal Protocol: 25 years protecting the ozone layer


Adopted in 1987, the Montreal Protocol has stimulated major progress in protecting the world’s ozone layer over the past quarter of a century. Its mission is not yet accomplished, but its successes and the way it has achieved them could provide valuable lessons to address other global challenges such as climate change.

Climate change is today’s number one environmental treaty challenge. But 25 years ago, depletion of the ozone layer through increasing atmospheric concentrations of man-made chemicals and the dangers this posed to the planet caused greater alarm.

The Montreal Protocol – the only environmental treaty ever to be universally ratified – has proved to be highly successful in healing the ozone layer. It has led to the phase out of 98% of the production and consumption of ozone-depleting substances (ODS). ODS were used in common applications such as refrigeration, air conditioning and insulation. Providing the Protocol continues to be fully applied, the ozone layer should make a complete recovery, returning to pre-1980 levels by mid-century.

" The Montreal Protocol has led to the phase out of 98% of the production and consumption of ozone-depleting substances "

The achievements have brought huge health benefits, helping to avoid millions of cases of fatal skin cancer and ailments such as eye cataracts. They have also contributed to the fight against climate change, avoiding emissions equivalent to over 135 billion tonnes of carbon dioxide.

Challenges and lessons

Despite this progress, the Montreal Protocol's work is far from complete. Governments need to ensure the existing restrictions are properly implemented and ODS in refrigerators, air conditioners and insulation foams still need to be properly eliminated through effective recovery and destruction. Vigilance will also be necessary to prevent any illegal trade in ODS.

Hydrofluorocarbons (HFCs) pose a new threat. They do not harm the ozone layer, but are potent greenhouse gases contributing to climate change. The European Union wants the Montreal Protocol expanded to cover their phase-down.

The experience and features of the Protocol could prove instructive for the future global climate treaty. The Protocol is legally binding, not simply a series of political pledges. It contains a clear timetable of targets, many of which the EU has achieved ahead of schedule. These can also be adjusted to reflect the latest scientific knowledge. Finance has been made available to assist developing countries achieve their commitments.

The Protocol also includes provisions that preclude parties from trading in ODS with countries that have not signed up to certain rules. These provisions help make it unattractive for countries to be free-riders and not participate in the joint effort.

Not surprisingly, Climate Action Commissioner Connie Hedegaard says: ‘This has proven to be an effective approach that the world might also want to consider in the design of the new climate agreement.’


Climate action