In a human lifetime, the mid-thirties can be a time of reflection: to think about what we have achieved and look ahead to what more we can accomplish. It is no different for the Montreal Protocol to Protect the Ozone Layer, the most successful environmental treaty to date.

As the treaty turns 35 on World Ozone Day, we will remember how the Montreal Protocol ended one of the biggest threats ever to face humanity as a whole: the depletion of the ozone layer. When the world found out that ozone-depleting gases used in aerosols and cooling were creating a hole in the sky, they came together. They showed that multilateralism and effective global cooperation worked and they phased out these gases. Now the ozone layer is healing, allowing it once again to shield humanity from the sun’s ultraviolet radiation.

This action has protected millions of people from skin cancer and cataracts over the years since. It allowed vital ecosystems to survive and thrive. It safeguarded life on Earth. And it slowed climate change: if ozone-depleting chemicals had not been banned, we would be looking at a global temperature rise of an additional 2.5°C by the end of this century. This would have been a catastrophe.

In the year of Stockholm+50, marking five decades since the landmark conference that kick-started today’s environmental global movement, the Montreal Protocol has much more to give. Under the Kigali Amendment, nations have committed to phase down hydrofluorocarbons – a move that could avoid up to 0.4°C of global temperature rise by the end of the century. The Protocol and its Amendment are helping the world adopt climate friendly and energy-efficient cooling technology.

What does this mean for humanity? As we continue to protect the ozone layer, it will continue to safeguard us and all life on Earth. It also means a cooler planet as more countries ratify the Amendment. It means more people being able to access vital cooling technology without further warming the planet. It also means the Protocol continuing to send a clear and lasting message: global cooperation to protect life on Earth is our best chance at a brighter future for everyone.

The theme for the 2022 International Day for the Preservation of the Ozone Layer, to be marked on 16 September, is Montreal Protocol@35: global cooperation protecting life on earth

The theme recognises the wider impact the Montreal Protocol has on climate change and the need to act in collaboration, forge partnerships and develop global cooperation to address climate challenges and protect life on earth for future generations.