"This Story Is Good": 40 Years Ago, Scientists Discovered A Hole In The Ozone Layer And Saved The Planet

It wasn’t the «Don’t look up» situation - the world acted quickly, and it worked.

Today, forty years ago, a trio of British scientists reported that something strange and very unexpected had happened in Antarctica. At that time they did not know it, but they «accidentally» (their words, not ours) made one of the greatest geophysical discoveries of the 20th century and started one of the most important scientific stories of recent memory.

On May 16, 1985, the team published an article in the journal Nature, which clearly showed that there was a hole in the ozone layer of the atmosphere over Antarctica. This was the culmination of many years of work by three researchers from the British Antarctic Survey - Joe Farman, Brian Gardiner and Jonathan Shanklin - who calmly collected and analyzed data collected by Dobson’s ozone spectrophotometer, a squeaking device developed in the 1920s that could measure atmospheric ozone. This will lead to the conclusion of the first ever global treaty to solve environmental problems, the Montreal Protocol, which was signed by every country on Earth.

At first, they weren’t looking for anything extraordinary. They were just trying to better understand the atmosphere over Antarctica. But in 1981, their data began to show some disturbing, inexplicable patterns.

«I went to the summer with a brand new Dobson, because the idea was that perhaps some of these readings were caused by a malfunction of the device,» Shanklin told IFLScience.

«I had some feedback from people who said that the data is falling from the chart [...] It started to look like something was wrong. But equally, people were not sure, because it could be just once,» he added.

Only after Shenklin collected the data of the previous decade, collected by Joe Farman, the unexpected readings took a new meaning. Shanklin explained: «I came back 10 years after he [Farman] wrote his main report, and I was able to show that it was systematic. Every year in spring, the ozone was slightly less than in the previous year.»

«I collected a draft and put it on his table, Brian Garner’s desk and their boss’s table - and watched the sparks fly.»

The ozone layer, located 15 to 30 kilometers (9.3 to 18.6 miles) above the Earth’s surface, is a band in the atmosphere with a high concentration of ozone gas. This gas helps to absorb harmful ultraviolet rays from the Sun, acting as an invisible shield for life on Earth. Without it or with a big hole in it, we are bombarded with much more radiation, which will lead to higher rates of skin cancer, cataracts and damage to the immune system, and will also disrupt ecosystems, especially plankton at the base of the ocean’s food chain.

Ozone levels in Antarctica vary depending on the season. The ozone hole usually reaches its largest size during the Antarctic spring (from August to October), and before gradually decreasing and eventually disappearing by the beginning of summer (December).

Since the 1970s, scientists have been concerned that CFCs - anthropogenic gases used in aerosol spraying and cooling - could harm the ozone layer. The leading theory of the time suggested that any damage is likely to occur high over the tropics, at altitudes of more than 40 kilometers (24 miles), where intense ultraviolet radiation is most common. This ultraviolet radiation will destroy CFC molecules, releasing chlorine atoms, which can then catalytically destroy ozone.

However, a 1985 study almost revealed the opposite: the depletion of the ozone layer occurred in Antarctica - and occurred at a dizzying rate.

This was due to the fact that extremely cold atmospheric conditions and the formation of polar stratospheric clouds created an environment in which chlorine compounds from CFCs could become highly reactive. When sunlight returned to the region in early spring, these reactive chlorine molecules quickly broke down ozone, leading to a sharp thinning, now known as the ozone hole.

«There were many other suggestions about what could happen. Initially, the satellite people thought: «Well, it’s clearly a solar activity that shares this.» They had data for six years, half of the solar cycle, so you could get a very good correlation between them based on this data. But correlation is not the same as causal relationship,» Shenkin said.

A 1986 article by scientists in the United States confirmed complex chemistry and confirmed that CFCs are directly responsible for ozone depletion in Antarctica. It became clear that the world needs to unite, form a plan and abandon the use of these chemicals as soon as possible.

Montreal Protocol: the world’s first global environmental treaty

It is noteworthy that this is exactly what happened. In 1987, just two years after the publication of the discovery of the ozone hole, 197 countries and the European Union signed the Montreal Protocol, which terminated KFU and, very importantly, took precautionary measures that would allow the protocol to later ban ozone-depleting chemicals that had not yet been invented.

To date, this is the only UN treaty that has been ratified by all countries of the world and has been described by former UN Secretary-General Kofi Annan as «perhaps the most successful international agreement to date».

Compared to the painfully slow progress in overcoming the climate crisis, the success of the Montreal Protocol is amazing. So, how did this serious action happen so quickly? He had a clear message and a simple solution, but perhaps most importantly, it did not require radical changes in lifestyle from people, and the status quo was relatively intact, Shenklin told us. Politically and economically, there was also something to gain.

«Thinning ozone allows more UV radiation to the surface and more UV radiation for skin cancer and cataracts, so there is a public health problem. Cancer has been a big problem in the political plate for a long time,» Shenklin explained.

«The manufacturers were very happy to switch to an alternative. Since CFC patents were approaching the end of the 50-year period, they could make more money by producing alternatives,» he added.

In general, the rapid action taken due to the scientific evidence presented has led to a steady reduction in the size of the ozone hole over the past 40 years, with full recovery in sight (as long as any new threats are kept under control).

When will the ozone hole recover?

«I think recovery by the second half of the century is reasonable,» Professor John Pyle, a leading atmospheric chemist and former co-director of the Center for Atmospheric Sciences, who played an important role in the Montreal Protocol, told IFLScience.

Nevertheless, there are good reasons to be careful. While the ozone hole is on the way to recovery, the progress is fragile. In recent years, fraudulent emissions of prohibited substances such as CFC-11 have been discovered and date back to China, which suggests that compliance is not ideal. Climate change itself can also complicate recovery, as changes in atmospheric temperature and circulation patterns can affect how ozone is formed and depleted.

Early studies also show that satellite and rocket launches, which have become alarmingly common in recent years, can also have a negative impact on the ozone layer, both during the launch and when the satellite is re-entered.

Despite these premiums, the Montreal Protocol remains a landmark example of global political cooperation in addressing the environmental crisis. This showed that with clear science, coordinated policy and international commitment, significant changes are possible. Unfortunately, the wound with climate change turns out to be much more difficult.

Climate change is a completely different story

"The history of climate is much, much more complicated than the history of ozone," Professor Pyle told IFLScience.

"The Montreal Protocol showed that you start with very small steps, but you get better as science gets better and as you get more people on board. This is not really happening with the climate, and for a good reason: the climate is very difficult."