2 days ago
Back in the ozone: How we plugged the hole in the sky
Once upon a time, well in the 1980s, the world looked up and discovered we'd poked a hole in the sky. Not metaphorically, not in some sci-fi dystopia, but literally, a yawning gap in Earth's ozone layer — the invisible shield that protects us from the Sun's harmful ultraviolet (UV) rays. And the culprit wasn't alien invaders or a rogue comet, but something far more mundane: hairspray, fridges, and air-conditioners.
The hole over Antarctica quickly became a potent symbol of human overreach. Scientists had been warning since the 1970s that chlorofluorocarbons (CFCs), the miracle chemicals that made spray-on deodorant, whipped cream in a can, and frost-free freezers possible, could destroy ozone molecules in the upper atmosphere. But it wasn't until 1985, when British scientists Joe Farman, Brian Gardiner, and Jonathan Shanklin published shocking measurements from Antarctica that it was fully apparent. The data showed a massive seasonal depletion of ozone each spring.
The problem was simple chemistry, though with catastrophic implications: CFCs drifted up to the stratosphere, where intense UV light broke them apart, releasing chlorine atoms that shredded ozone molecules like confetti. Less ozone meant more UV radiation reaching Earth's surface, increasing the risk of skin cancer, cataracts, crop damage, and who knows what else.
A rare plot twist
In environmental stories, the plot often goes like this: scientists warn, politicians dither, lobbyists stall, and the problem worsens. But the ozone saga took a refreshingly different turn. The images of the gaping hole and the undeniable science spurred action. Just two years after the Antarctic discovery, the world signed the Montreal Protocol in 1987, which is a global agreement to phase out ozone-destroying substances. It remains the most successful environmental treaty in history, with every single United Nations member country signed on.
Industry initially grumbled (of course), warning of costs and inconvenience, but quickly pivoted to invent safer alternatives. The chemical companies that had made fortunes from CFCs soon made fortunes from the replacements. It was, in its way, capitalism at its most adaptable.
The long, slow healing
Fixing the ozone hole was never going to be instant. CFCs are stubborn chemicals, hanging around in the atmosphere for 50 to 100 years. Even after production stopped, the stockpiles we'd already released were still floating upwards to do their damage. The ozone layer, battered for decades, needed time to recover.
The Ozone 'hole': This satellite image was obtained by the NASA Total Ozone Mapping Spectrometer (TOMS). It is centred on the South Pole where the so-called ozone 'hole' was first observed by the British Antarctic Survey in the mid-1980s. This was achieved through measurements from the land base at Halley Bay using a device to measure ozone UV absorbance. Pic: NASA 2018
But something remarkable happened: it started working. By the early 2000s, scientists detected the first signs that ozone levels were stabilising. In 2018, NASA confirmed the hole was shrinking, and that it wasn't just due to natural fluctuations, but because the Montreal Protocol was working exactly as intended. By 2023, scientists reported that the Antarctic ozone hole was on track to heal completely by the mid-21st century.
An accidental climate bonus
The Montreal Protocol didn't just protect the ozone layer, it also delivered an unexpected climate win. CFCs are not only ozone-destroyers; they're also powerful greenhouse gases, thousands of times more potent than CO₂ at trapping heat. By phasing them out, the treaty avoided an enormous amount of future warming.
So, in a strange twist, the effort to protect us from UV rays also gave us breathing room on carbon emissions. Though sadly, we've used that room to keep emitting CO₂ at record levels. Still, it's a rare and satisfying example of an environmental win.
Not quite out of the woods
Lest we get too smug, there have been bumps along the way. In 2018, scientists detected unexpected spikes in CFC-11 (one of the banned substances) traced to illegal production in parts of China. But (here's the encouraging part) because the Montreal Protocol has teeth, countries investigated, cracked down, and the emissions dropped back down. Imagine if we treated carbon emissions with the same global seriousness.
There's also the newer problem of HFCs [hydrofluorocarbons] (the CFC replacements), which don't harm ozone but are still potent greenhouse gases. The 2016 Kigali Amendment to the Montreal Protocol now addresses that, aiming to phase down HFCs too. It's like realising your roof's fixed but your walls are mouldy... you keep patching until the whole house is sound.
A story worth remembering
In a world where the news is usually a cascade of crises, the ozone recovery is the feel-good environmental story we need. It's proof that science can spot a problem before it becomes irreversible, global cooperation is real and possible, industry can innovate its way out of trouble when pushed, and nature can heal if we give it the chance.
It's also a lesson in timing. We acted before the damage spiralled beyond repair, and the payoff is now visible. Contrast that with climate change, where we're still foot-dragging, and the lesson is clear: earlier action saves bigger headaches later.
Looking up
So, where are we now? As of 2025, the ozone layer is still healing. If all goes well, the Antarctic hole will be gone by around 2066, and the rest of the planet's ozone will return to 1980 levels decades before that. Children born today could live to see a fully repaired sky.
It's worth looking up sometimes and remembering that we, collectively, fixed something. We didn't rely on miracle tech or some billionaire's pet project, we relied on science, diplomacy, and a shared sense of 'let's not fry ourselves'. And it worked.
The next time someone says 'people never change' or 'countries can't work together', tell them about the ozone hole.
Then remind them that if we could do it once, we can do it again, whether it's climate change, biodiversity loss, or the plastic in our oceans. After all, we once had a hole in the sky. Now we have a blueprint for how to mend the planet. And that, in anyone's book, is a good news story.
