Almost 30 years ago, the world's countries joined hands in an unprecedented effort to tackle an invisible, yet very real threat to humanity – the depletion of the ozone layer – Earth's only shield from harmful ultraviolet rays.
The result was the Montreal Protocol on Substances that Deplete the Ozone Layer, which remains to this date the most successful UN environmental agreement in history. Ratified by 197 parties, it has led to a 98 per cent decrease in the production and use of ozone-damaging chemicals, helping the ozone layer to start recovering, saving an estimated two million people each year by 2030 from skin cancer and contributing to mitigating climate change at the same time.
As we prepare to celebrate the International Ozone Day, the spirit of unity that led to its adoption and implementation once again permeates global environmental negotiations. Last year, a record number of countries signed the landmark Paris Agreement on climate change and earlier this month the world's two largest economies – US and China – ratified it.
As the world unites to counter the changing climate, the Montreal Protocol can once again play an important part. Its 197 parties will meet in Kigali, Rwanda next month to work towards agreeing on phasing down the climate change-inducing hydrofluorocarbons (HFCs).
Widely used in refrigeration and air conditioning as substitutes for ozone-depleting substances, HFCs are thousands of times stronger than carbon dioxide at causing global warming. Their phase-down under the Montreal Protocol could prevent a global temperature rise of up to 0.5°C by the end of the century, making it one of the most significant actions on climate change the world can take this year.
The success of the Montreal Protocol is the best example of what can be achieved when the world acts together. Almost three decades on, that unity of purpose can be once again harnessed to protect and restore our planet's climate, while continuing to protect the ozone layer.