What happened to the Ozone layer scare? Hint: we fixed it

Perhaps some of you remember the news and discussion throughout the 80s and 90s about the hole forming in the ozone layer over Antarctica. It was talked about a lot, but then it dropped off the radar. Some even use it as a way to discount climate change: “30 years ago it was the ozone layer, now it's climate change”. It’s true that it isn’t talked about now, but why?

A bit of background to refresh your memory: Forty years ago, British scientists discovered a decrease in the concentration of stratospheric ozone over Antarctica. This layer prevents the sun's shortest wavelengths of ultraviolet light from reaching the Earth's surface. If this shield were to weaken, the consequences would be significant: genetic damage to microorganisms, bleaching of chlorophyll in some plants (hindering their growth), an increase in skin cancer cases in humans, and eye injuries.

Years earlier, scientists had identified the negative effect of compounds called chlorofluorocarbons, or CFCs. These were widely used in refrigerators, air conditioners, and aerosols, among other everyday products. When released, these gases rise into the stratosphere, where sunlight breaks them down, releasing chlorine atoms that destroy ozone molecules.

Upon detecting this problem in the mid-1980s, significant public pressure built as the serious health risks linked to rising skin cancer rates became impossible to ignore. Faced with this demand, governments were compelled to seek a solution. It was then that the political leadership of figures like British Prime Minister, Margaret Thatcher, became indispensable. Her background as a chemist allowed her to understand the issue and authoritatively explain the science behind it to other world leaders.

In this context, the Montreal Agreement was created in 1987, becoming the first UN treaty ratified by all member states. Finally, the treaty's success was secured because industry had already begun developing viable and economical alternatives, such as propane, butane, and HFCs, ensuring the technological transition.

Furthermore, the Montreal Protocol was designed to function in the long term: a scientific review was stipulated every 4 years to analyze and regulate new substances that could harm the ozone, ensuring the agreement could adapt to new knowledge.

Thanks to this flexible structure and its compliance, we are not only on track to heal our solar shield by 2066 (according to NASA), but, as recent studies reveal, this joint action is also helping us avoid between 0.5 and 1°C of additional warming by the end of the century. It should be clarified that while HFCs are also greenhouse gases, they have a shorter atmospheric lifetime than the old CFCs.

Ultimately, this entire story is proof that humanity can unite and correct its course in the face of a global environmental crisis. It showed us that with a solid scientific foundation, industrial innovation, and international political collaboration, it is possible to generate positive changes at a global scale.

Solving climate change is a much more complex and systemic challenge without a single solution like banning CFCs. However, we are already applying the same formula on a larger scale: progress in the global expansion of renewable energy, growing public engagement, and the development of environmental regulations, and international discussions around climate change are signs that the world is using the lessons of the past to tackle one of the greatest challenges of our present. While there’s a lot of work to do, the job now is to accelerate the progress we are already making; we are already moving in the right direction.