earth planet

In the 1980s, the world was terrified by the threat of holes in the ozone layer. Today, these holes are almost gone. How did this happen? How did humans heal the ozone layer? And are there any lessons we could learn from this?

Listen Here!


  • Ozone (n) – a colourless gas that is a form of oxygen
    • The ozone layer absorbs radiation from the sun
  • Atmosphere (n) – the mixture of gases around the earth
    • These factories are releasing toxic gases into the atmosphere
  • Stratosphere (n) – a layer in the upper atmosphere of a planet where the temperature increases with height
    • The ash cloud rose 35km into the stratosphere
  • Radiation (n) – energy in the form of waves or particles
    • Ultraviolet radiation can cause skin cancer
  • CFC (n) – abbreviation for chlorofluorocarbon: a gas used in fridges and, in the past, in aerosols
    • CFCs cause damage to the ozone layer
  • Molecule (n) – the smallest unit into which a substance can be divided without chemical change, usually a group of two or more atoms
    • An ozone molecule contains three oxygen atoms
  • Protocol (n) – a formal international agreement
    • The Geneva Protocol of 1925 prohibits the use of poisonous gases in war.
  • To ratify (v) – (especially of governments or organizations) to make an agreement official
    • Many countries have now ratified the UN convention on the rights of the child.

Climate Change and the International Community

Climate change and global warming are going to be major themes over future years and decades. As temperatures warm, sea levels rise, and weather becomes more unpredictable, humans around the world will need to work together to solve the causes and combat the consequences.

The environment is, in many ways, a uniquely challenging thing to unite people around. Why? Well, it is a cross border problem. A country in Europe, North America, or Asia could burn countless kilograms of coal and release significant amounts CO2 into the atmosphere… but the damage may be felt on the other side of the world – in the Pacific island nations struggling against rising sea levels or the countries facing natural disasters.

It is really difficult to make different countries work together to solve issues, especially if they are not experiencing the worst consequences. The countries that are most affected by climate change are usually not the countries contributing the most damaging emissions. We can see how difficult it has been to get countries to set targets to cut emissions in recent COP meetings.

There is an exception to this. There is an example of almost every country agreeing to work together to solve an environmental problem. A feat that was described by UN secretary-general Kofi Annan in 2003 as “perhaps the most successful international treaty to date.” What is this exception? The ozone layer!

The Ozone Layer

Our planet is surrounded by layers of gases. This is called an atmosphere. And the atmosphere has different layers that consist of different gases and features but are all essential for life to exist on our planet.

The second layer of the atmosphere is called the stratosphere, which includes ozone gas at the higher levels. There is actually only a tiny amount of ozone in the stratosphere, but it has a vital role. Ozone can absorb radiation from the sun, especially ultraviolent radiation or UV light, which can be harmful to life on earth.

Too much UV light can damage the molecules in plants and animals. In humans, it is the cause of sunburn and skin cancer. It can damage plants and crops. And it is harmful to fish and plankton that live in the oceans and are a key part of food chains and ecosystems.

As the ozone layer absorbs some of this harmful ultraviolet radiation it is a kind of shield for our planet, protecting the plants and animals that live on the earth’s surface. In fact, the ozone layer absorbs around 98% of UV light… it is incredibly important.

In 1985, scientists discovered something terrifying. They found that an area of the ozone layer above Antarctica was really thin. It popularly became known as a hole in the ozone layer (technically it is more like a thin patch than an actual hole). And with less ozone in the atmosphere, there was more damaging UV light being let through the earth’s protective shield.

Why was the ozone layer getting thinner? Due to chemicals called chlorofluorocarbons (CFCs). These chemicals were widely used in products and businesses: from plastic to hairspray. CFCs were relatively safe to people and inexpensive, making them a popular choice.

However, CFCs were found to be able to stop the formation of ozone. An ozone molecule is three atoms of oxygen joined together. While ozone is naturally being made and broken down in the atmosphere, CFCs block the formation of ozone. With higher CFCs in the atmosphere, there is less and less ozone and the atmosphere become dangerously thin.

How was the ozone layer fixed?

Two years after the scientists found the “hole” in the ozone layer in 1985, world leaders came together to sign the Montreal Protocol. In signing the Montreal Protocol, countries promised to phase out the use of CFCs.

And it has been incredibly effective. The ozone layer is not just repairing itself, but it will be back to same state as the 1980s relatively quickly. Over 99% of CFCs in the atmosphere have gone. By 2040, most of the world will have its ozone replenished, and the hole over Antarctica should be repaired fully by 2066. And health officials in the USA estimate that around 440 million cases of skin cancer in the USA will be avoided this century due to the Protocol.

Moreover, as CFCs are also greenhouse gases that can trap heat, banning them has helped to slow climate change. The Montreal Protocol is probably the most effective environmental policy in history.

There are a few reasons why this was such an effective policy. One is scientific. CFCs in the atmosphere stop the formation of ozone. Therefore, banning CFCs and stopping their release can undo the damage and allow the ozone to reform. It is a relatively simple and understandable fix. We can see the damage, know the consequences, and know how to fix it!

But how did the Montreal Protocol get the support of so many countries? It is one of the only international treaties supported by every single country – it was universally ratified. That is not an easy task… to get every member of the UN to agree on something is rare! But when Palestine signed in 2019, the Montreal Protocol was officially universally approved.

The Montreal Protocol offered money to countries to encourage them to join. This made the likes of India and China, who are often reluctant to join environmental treaties, think positively about banning CFCs.

Countries were also convinced to ban CFCs for other reasons. CFCs were not as important to economies or companies as oil, gas, and coal (the products currently causing so much damage). And the science was clear!

All of these factors allowed the world to drastically reduce the emission of CFCs, and basically fix the “holes” in the ozone layer.

Do you want to Think in English?

I’m so excited that you found my blog and podcast!! If you don’t want to miss an article or an episode, you can subscribe to my page!

What can we learn from the Ozone Layer?

Healing the ozone layer is one of the most successful international efforts in human history. But now we have other environmental problems causing damager to our planet – rising temperatures, pollution, and greenhouse gases!

For some reason, the world has not been able to unite over climate change in the same way the did over the ozone layer. What lessons can we learn from fixing the ozone layer, that may be helpful to other international climate change efforts?

One thing is that politicians acted fast with the ozone layer. Scientists knew that CFCs could damage ozone, but they were not completely sure about the impact on the earth. However, the risk to people, crops, and the oceans convinced politicians to act straight away (even if the science was not settled). And they made the right decision! But with climate change…. Politicians have been influenced by lobbyists instead of scientists.

World leaders acting fast was a clear reason why the ozone layer started to repair itself. It took around 16 years for countries to discover the effects of CFCs and sign the Montreal Protocol.  Scientists started to talk about the impact of greenhouse gases and carbon dioxide in the 1960s… but emissions are still increasing today – the effort to fix the ozone layer benefited from speed!

Rich countries also gave money and support to poorer countries. CFCs were never as important as fossil fuels are but banning them did cause problems. There were manufacturing companies, especially those making spray cans and refrigerators, that closed down or needed to invest in new technology. Richer countries helped poorer countries deal with the changes – this is something needed today, but the money required is much higher.

And finally, the way we talk about international issues is important. The idea of a “hole” in the ozone layer is easy to understand and scary. Climate change is not as clear. Temperatures raising by a few degrees doesn’t have the same impact as a hole in the ozone!

The image, finances, action of leaders, and speed were all elements that helped the world fix the ozone layer. And these are lessons the world should learn to unite around the issue of climate change!

Never miss an episode

Subscribe wherever you enjoy podcasts:

Final Thought

We have almost fixed the ozone layer. Every country in the world came together to ban the use of CFCs, and it has been incredibly effective. Today I hopefully introduced you to some important vocabulary, while also talking about the lessons we could learn from the effort to fix the ozone layer!

What do you think? What is the best way to combat climate change?

Donate to Thinking in English!


Make a one-time donation

Make a monthly donation

Make a yearly donation

Choose an amount


Or enter a custom amount


Your contribution is appreciated.

Your contribution is appreciated.

Your contribution is appreciated.

DonateDonate monthlyDonate yearly
Liked it? Take a second to support Thinking in English on Patreon!
Become a patron at Patreon!

By Tom Wilkinson

Host and founder of Thinking in English, Tom is committed to providing quality and interesting content to all English learners. Previously a research student at a top Japanese university and with a background in English teaching, political research, and Asian languages, Tom is now working fulltime on bettering Thinking in English!

Leave a Reply