This month marks the 35th anniversary of the Montreal Protocol, the agreement that made a global cut in ozone-depleting substances possible. The ozone layer faced a real threat in the 1980s, but the actions that followed proved that humanity can tackle planetary-scale problems when science is heard and acted upon. The protocol stands as a clear example of how collective effort and evidence-based policy can repair harm on an international stage.
The news isn’t all grim. Even amid environmental pressures there are hopeful signs. Notably, the ozone layer, long damaged by CFCs from cooling systems and aerosols such as hairsprays, has been gradually recovering. The hole’s surface has narrowed in recent years, and multiple projections point to continued improvement, suggesting the fight against ozone depletion is moving in the right direction.
How did this progress unfold? It started in the early 1970s when a small group of environmentalists and scientists warned about ozone loss. Despite initial skepticism from some, two influential leaders, from the United Kingdom and the United States, Margaret Thatcher and Ronald Reagan, championed action. They signed the Vienna Convention in 1985 and the Montreal Protocol in 1987, with broad support from nearly 200 countries. Their leadership helped mobilize resources and political will, and the planet began to heal.
Thatcher, known for her iron resolve, remains a controversial figure for domestic policies, yet several of her choices helped drive environmental progress. A background in chemistry gave Thatcher insight into the ozone threat, and her influence, together with Reagan’s, accelerated the agreement. The core takeaway is plain: political leadership that values scientific findings can spark meaningful, lasting change.
counter movements
Resistance existed. The CFC industry, a cornerstone of economic activity because these gases power refrigeration and cooling systems, pushed back against bans. Observers note that eliminating these substances was seen by some as a risk to development for certain economies. This tension highlights a recurring reality in environmental policy: balancing short-term economic needs with long-term planetary health. In the United States, debates and misinformation mirrored broader climate challenges, complicating public understanding of the ozone issue to this day.
Though ozone depletion and climate change are separate topics, CFCs are greenhouse gases that contribute to warming. So, phasing them out 35 years ago also delivered ancillary benefits for the wider climate fight.
2060: endpoint
What is the current status of the ozone hole? Recent European satellite data from Copernicus-Sentinel monitoring indicate ongoing improvement, though the pace may be gradual because CFCs linger for decades. Scientists have set 2060 as a practical milestone for considering the ozone issue substantially resolved, acknowledging that complete disappearance is not guaranteed and progress could continue to evolve with time.
Unforeseen complications cannot be ruled out. In recent years, scientists observed an additional ozone hole over the Arctic, atop the existing Antarctic hole. Although the anomaly sparked concern, the following weeks saw the Arctic opening close. Experts note that meteorological events influence these patterns and stress that this phenomenon should not be linked to unrelated health events or pandemics.
don’t let your guard down
Staying vigilant remains essential. Vincent-Henri Peuch, head of the monitoring program, warned that ozone recovery depends on climate trends, since cooling or warming of the stratosphere can affect ozone loss dynamics. There is also a risk of unauthorized emissions of ozone-depleting substances, which has occurred in the past due to undetected leaks from certain regions. Such episodes underscore the need for continuous monitoring and robust regulation.
In a counterfactual scenario, NASA has warned that without global mobilization, ozone depletion could have intensified. By the middle of the century, two-thirds of the ozone layer might have been compromised, sharply increasing ultraviolet radiation exposure and potentially raising skin cancer risks. The message remains stark: policy choices today shape health outcomes decades later. Scientists remind the public that Earth operates as an interconnected system where changes in one part ripple through the whole.
That interconnected view serves as a reminder that human activity touches every corner of the planet. Protecting the ozone layer has taught a broader lesson about stewardship and the responsibility to act when evidence shows risk to the atmosphere we all share.