What is the ozone layer?
The Ozone (with chemical formula O3) is a molecule composed of three atoms of oxygen, reason why it is also known as trioxygen. It forms a natural belt or “shield” in the upper atmosphere (at 20 km to 30 km above Earth), also called stratosphere.
This ozone layer protects us from solar ultraviolet (UV) radiation. For this reason, it is considered one of the primary greenhouse gases in the atmosphere, alongside water vapor, carbon dioxide, methane and nitrous oxide.
These greenhouse gases absorb and emit radiant energy in order to maintain the average temperature of Earth’s surface in about 15°C (59 °F). Without these gases, the temperature would be about -18°C (0 °F), and life would be less viable.
What is the ozone layer depletion?
Since the beginning of the Industrial Revolution the emissions of carbon dioxide to the atmosphere have massively increased, partially destroying this protection layer and driving to the ozone layer depletion, commonly known as “the ozone hole”.
It is one of the most serious problems faced by our planet earth. Without this protective layer preventing the entrance of ultraviolet radiations with high energy electromagnetic waves, our planet would suffer some issues, such as global warming, and the humanity would have serious difficulties to survive.
If you would like to have a look at the ozone layer right now or last months, you can take a look to NASA’s ozone map.
Causes of the destruction of the ozone layer?
About 80% of the total ozone layer depletion is due to the production and emission of chlorofluorocarbons (CFCs). At stratospheric levels, CFCs convert into chlorine, which reacts with ultraviolet rays to destroy ozone on a massive scale.
This conversion from CFCs to chlorine is faster at lower temperatures, and explains why the ozone layer above Antarctica has been extremely damaged. In Antarctica the hole in the ozone layer can be clearly seen growing since mid-1980s.
Other air pollution compounds contributing to the ozone layer reduction are hydrochlorofluorocarbons (HCFCs) and volatile organic compounds (VOCs). Both, maintain stable at lower atmospheric levels and react with sun rays at the stratosphere, just as CFCs do. The emissions of these gases come from aerosols, refrigerants, industrial processes, and obviously from vehicles combustion engines.
Effects of the ozone hole to the environment and health
When high energy electromagnetic waves reach the Earth’s surface, both the planet and humans are exposed to several harmful effects due to the ozone layer depletion.
For humans, direct exposure to UV rays can lead to:
- Skin cancer such as melanoma, basal cells or squamous cell carcinomas.
- Premature aging and other skin damage.
- Eye damage such as cataract problems, photokeratitis or snow blindness.
- Damage or weak the immune system.
In plants, despite being prepared and adaptable for incrasing levels of UVB, ozone layer depletion can cause problems such as: form changes on how nutrients are distributed, on developmental timing phases and on secondary metabolism.
On marine ecosystems, exposure to UVB reduce survival rates of phytoplankton and harm early developmental stages of fish, shrimp, crab, amphibians and other marine animals. Furthermore, short wave ultraviolet B (UVB) sun rays can also alter terrestrial and aquatic biogeochemical cycles.
Ozone layer depletion is obviously one of the main reasons that contribute to global warming, applying over Earth’s surface a greenhouse effect and increasing its temperature. Actions that warm our planet’s surface contribute to climate change, with direct and indirect effects in almost all ecosystems and organisms. This is why the ozone layer is so important, for the Earth, for us!
Ozone layer depletion prevention
To sum up, destructing the ozone layer does not help anyone, we are putting everything and everyone in danger!
Despite the creation of some international laws and agreements to preserve the environment and reduce CFCs emissions (such as Montreal Protocol, Kyoto Protocol, The Paris Agreement and many other national laws), everyone needs to take part and change some habits or with different daily practises. Here are some examples:
- Buying and using recycled products.
- Saving of energy:
- Change your light bulbs to CFL
- Use less heat and air conditioning
- Buy energy-efficient products
- Use less hot water
- Use the “off” switch
- Reducing fossil fuels emissions by using public transport.
- Plant a tree (or two!).
- Spread awareness and encourage others to make a change.