International Day for the Preservation of the Ozone Layer – celebrating 35 years of ozone layer protection

What is ozone and where is the ozone layer?

Ozone is a gas that is made up of 3 oxygen atoms (O₃) and occurs naturally in the Earth’s atmosphere. It is also created via chemical reactions due to human activity. But did you know that there is both good and bad ozone? So what’s the difference?

Good ozone

Surrounding the Earth, there are 5 atmospheric layers. These are the troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere. The stratosphere is the second-closest part of the atmosphere to the Earth’s surface. It starts around 12 kilometres from the Earth’s surface, and ends around 50 kilometres high. Most of the atmosphere’s naturally-occurring ozone is found in this area. This area is therefore known as the ozone layer.

At this level, ozone absorbs the majority of the Sun’s harmful UV rays to protect life on Earth. Without the ozone layer, the Sun’s rays would be able to hit the Earth’s surface at full strength. As a result, nothing would be able to survive. So the ozone layer has a pretty essential job!

Bad ozone

Ozone is also found in the troposphere. This is the layer of atmosphere closest to the Earth’s surface. It is sometimes known as ground-level ozone, and is a pollutant that damages crops and is harmful to breathe. Ground-level ozone is a “secondary” pollutant because it’s formed when two primary pollutants react with stagnant air and sunlight. These primary pollutants are usually nitrogen oxides (NOx) and volatile organic compounds (VOCs).

How did International Day for the Preservation of the Ozone Layer come about?

Discovery of ozone depletion

The Vienna Convention for the Protection of the Ozone Layer

What are CFCs and halons and where are they used?

CFCs (chlorofluorocarbons) are gaseous compounds made up of carbon, chlorine and fluorine atoms. They sometimes also include hydrogen, which makes them into HCFCs. Before they were developed in the early 1900s, more dangerous products such as ammonia were used. At this time, CFCs were preferable because they are non-toxic and non-flammable.

Before the Montreal Protocol, the majority of CFCs were used in a variety of common applications. These included refrigeration, air conditioning, insulation, packing materials, solvents and aerosol can propellants. It was therefore difficult to eradicate CFC use quickly. However, since 1987 the use of CFCs has been gradually phased out. CFC production ended worldwide in 2010 but some older appliances are still in operation. This means that CFCs from those appliances and items will continue to be released unless they are safely disposed of. It’s also been reported that some illegal CFC manufacture is still happening, but this has not been confirmed.

Halons are liquefied, compressed gases, that are known for their fire extinguishing properties. The manufacture of halon extinguishers is no longer allowed and halon extinguishers have been banned in the UK since 2003.

The ozone hole

The ozone hole is an annual thin spot that forms in the ozone layer over Antarctica in mid-September and October. This thinning occurs due to chemical reactions between man-made and naturally-occurring chemicals within polar vortexes. These reactions turn otherwise harmless chemicals, bromine and chlorine, into chemicals that destroy ozone.

The buildup of chemicals in the atmosphere has occurred over many years. This means it will take many more years to help repair the hole in the ozone layer.  This is why the world’s governments continue to honour the agreement that was made back in 1985.

International Day for the Preservation of the Ozone Layer introduced

In 1994, 16th September was named as International Day for the Preservation of the Ozone Layer. 2020’s theme is “35 years of ozone protection” because 1985 was seen to be the turning point towards ozone healing.

How healthy is the ozone layer today?

Is the ozone hole related to global warming?

The short answer to this is no. The issues caused by the damage to the ozone layer are unrelated to global warming. In fact, the hole in the ozone layer actually has a slight cooling effect on the planet. This is because the hole allows heat to escape at a faster rate than if it wasn’t there.

However, some important lessons can be learned from the action that’s been taken to heal the ozone layer. The world’s most powerful leaders have worked together to make a huge difference to ozone health. This means we could make a similar impact on the climate crisis to further protect our amazing planet.

Remember, there are always actions we can take as individuals to help the planet. So whether it’s safely disposing of your old fridge or trying some of our tips for living more sustainably at home, every effort helps.