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Ozone Layer

✨ Earth's Invisible Shield

The ozone layer is a region of the stratosphere, located about 15 to 35 kilometers above Earth's surface, where ozone gas is much more concentrated than in the rest of the atmosphere. Ozone is a molecule made of three oxygen atoms. Although it represents only a tiny fraction of the air, it plays a vital role by absorbing most of the Sun's harmful ultraviolet (UV-B and UV-C) radiation before it reaches the ground.

This natural shield helps protect humans from skin cancer and eye damage, while also safeguarding animals, plants and many microscopic organisms. Ozone is constantly being created and destroyed through natural chemical reactions driven by sunlight, maintaining a dynamic balance in the atmosphere.

During the twentieth century, scientists discovered that certain human-made chemicals, especially chlorofluorocarbons (CFCs) and related compounds, were damaging the ozone layer. Once released, these substances can remain in the atmosphere for decades before reaching the stratosphere, where they release chlorine and bromine atoms that destroy large numbers of ozone molecules.

This process led to the seasonal ozone hole over Antarctica and to ozone depletion in other regions. The adoption of the Montreal Protocol in 1987 greatly reduced the production of these chemicals, and observations show that the ozone layer is gradually recovering. Even so, continued monitoring remains important because full recovery will take several decades.

💡 Did you know?

Did you know that we have already managed to repair the ozone layer? About 40 years ago, scientists discovered it had giant holes at the poles because of gases used in fridges and sprays. Countries around the world agreed to stop these gases, and now the holes are slowly closing! It's proof that if we all work together, we can save nature.

Ozone is a gas that has a bit of a peculiar smell, both metallic and fresh. You can sometimes smell it after a big thunderstorm when lightning has torn through the air: it's the electricity that transforms normal oxygen into ozone. But be careful: while ozone is super useful when it's very high up, it's bad for our lungs if we breathe it too closely on the ground.

The ozone layer is found in an area of the sky called the 'stratosphere'. At this height, the air is very calm and there are almost never any clouds. This is why airliners prefer to fly just above the clouds but below the ozone layer: to avoid shaking while remaining protected by the shield.