International Day for the Preservation of the Ozone layer- September 16

On September 16, 2020, the globe is celebrating its 35 years of Ozone layer protection. It marks that collective decisions and actions, guided by science, are the only way to solve major global crises. The slogan for the day is “OZONE FOR LIFE”, which signifies that not only ozone is crucial for life on Earth, but also it must be protected and continue to do so for the future generation.

Let’s go through some of the facts to know more clearly about ozone and the ozone layer.

What is Ozone?

Ozone (O₃) is a gas with molecules made up of three oxygen atoms. The oxygen that we breathe (O2) has molecules made up of just two oxygen atoms, Ozone gas is produced naturally, in the stratosphere, 15 to 35 kilometres above the Earth’s surface but also lower in the atmosphere due to humans activity.

What is the Ozone layer?

The ozone layer is a region of high ozone concentration in the stratosphere, 15 to 35 kilometres above Earth’s surface. It acts as an invisible shield and protects us from harmful ultraviolet (UV) radiation from the sun. Long-term exposure to high levels of UV radiation threatens human health and damages most animals, plants and microbes, so the ozone layer protects all life on Earth.

Where did scientists first discover the hole in the ozone layer?

The scientists discovered severe depletion of ozone above Antarctica, in the mid-1980s. It was so severe that a “hole” had formed in the ozone layer in the Earth’s atmosphere. At first, the scientists believed that the reading of instruments was incorrect and didn’t trust their data because the drop in levels of ozone was so extreme it seemed impossible. But when they started comparing their data with each other, they soon realized humanity was facing a very big problem.

What causes the thinning of the ozone layer around the globe?

Chlorofluorocarbons (CFCs) and other man-made chemicals containing chlorine or bromine were determined to be the main cause of ozone loss. These chemicals are collectively known as ozone-depleting substances (ODSs). Chlorofluorocarbons (CFCs) were the most important ODSs because they were used in literally thousands of products that people used daily around the world, such as refrigerators, aerosols and air conditioners among others.

What product uses CFCs?

The most important ozone-depleting substances (ODSs) were chlorofluorocarbons (CFCs) which at one time were widely used in fridges, air conditioners, aerosol cans and inhalers used by asthma patients. But there were also other ODSs that were used in car dashboards, insulation foams in houses and office buildings, water boilers and even the soles of shoes! ODSs called halons were also used for fire protection in military bases, offices, aeroplanes and ships.

How would the climate of the Earth change without the successful control of ozone-depleting substances like CFCs?

CFCs are very powerful greenhouse gases. One CFC-12 is more than ten thousand times more powerful than carbon dioxide. Modelling studies show that by 2070 the effective control of CFCs through the Montreal Protocol will have prevented temperature increases of over 2 degrees C in the tropics and up to 6 degrees C in the Arctic.

What would happen if the ozone layer was destroyed?

With a weakening of the ozone layer shielding Earth, there would have been large increases in skin cancer and cataracts; plant growth and crop yields would be impacted by intense ultraviolet radiation, as would the plankton that serves as a source of food for most of life underwater. Intense UV radiation also damages construction materials such as wood, plastic, rubber and even the materials used in some solar panels.

 Is ozone depletion the main cause of climate change?

No, ozone depletion is not the main cause of global climate change, but the two are linked. One link is that some ozone-depleting substances (ODSs), including CFCs, are powerful greenhouse gases. By controlling ODSs the Montreal Protocol, through the Kigali Amendment, also helps protect the climate. The Antarctic ozone hole has affected atmospheric circulation in the southern hemisphere. This change in circulation has had impacts on regional climates in Southern South America, Southern Africa, Australia, and New Zealand.

What can you do to help protect the ozone layer?

Even though the Vienna Convention and Montreal Protocol have been successful in phasing out ozone-depleting substances, older equipment may still contain ODSs, so we need to make sure that we look after them properly and get them checked regularly to prevent those ODSs from escaping. By using our new appliances responsibly, we can also do our part to protect the ozone layer and the climate too. More at: https://ozone.unep.org/what-you-can-do

Source: United Nation Environment Programme