Every September 16th, the International Day for the Preservation of the Ozone Layer is celebrated. This date highlights the importance of scientific cooperation and international agreements to protect this atmospheric “shield” that shields us from harmful ultraviolet radiation.
The recovery path of the ozone layer is one of the greatest successes of global environmental action.
Thanks to the early detection of chemical substances that deteriorate it, governments, organizations, and scientists joined forces to implement unprecedented regulations.
The recovery of the ozone layer
This collective effort demonstrates that constant monitoring and cooperation are fundamental to address the environmental challenges that threaten the health of the planet and its inhabitants.
The key function of the ozone layer.
The experience with the ozone layer serves as a model for other complex problems. It reinforces the idea that, by acting in a coordinated manner and trusting scientific evidence, it is possible to achieve a positive and lasting impact.
Why is September 16 commemorated?
This day commemorates the signing of the Montreal Protocol, a historic international treaty signed on September 16, 1987. This agreement was a response to the detected damage in the atmosphere and established a cooperation mechanism for ozone protection.
Two years earlier, the Vienna Convention laid the legal foundations for research, monitoring, and preventive action. Both legal instruments, the Montreal Protocol and the Vienna Convention, were pioneers in the progressive elimination of harmful chemical compounds, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, and others.
These substances, commonly found in products like refrigerators, air conditioners, and aerosols, are the main culprits of ozone depletion. The agreements set deadlines for their eradication, demonstrating that global action driven by science is possible.
The Kigali Amendment of 2016 is an example of how these treaties are updated to also control high-impact climate gases such as HFCs, confirming the need for adaptation to new threats.
The current state of the ozone layer
The success of international policy and compliance with these treaties has allowed for a recovery process. According to recent studies, the ozone layer over Antarctica is on track for recovery, a result directly related to the global reduction of depleting substances.
A study from March 2025 led by Professor Susan Solomon from MIT used simulations and analysis to confirm that the ozone recovery is due to the decrease in CFCs and similar compounds. Solomon stated that, with 95% confidence, the ozone layer is recovering.
This milestone is not only great news for the planet but also compelling evidence that, as a society, “we can really solve environmental problems.”
