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Climate Change: The Ozone Layer
THE OZONE LAYER
What is The Ozone Layer?
The ozone layer is a protective layer of naturally occurring
ozone gas, found in the Earth’s stratosphere, 15 – 30
kilometres above the Earth’s surface.
Why is The Ozone Layer Important?
The ozone layer protects life on Earth because it acts as an
umbrella and shields us from 97 – 99% of the Sun’s
dangerous rays. By blocking out these rays, the ozone layer
stops them from reaching Earth’s surface.
Earth’s Ozone Layer
Have you ever had sunburn? This is caused by Ultraviolet
(UV) rays. If too many UV rays reach Earth, they can damage
humans, animals and crops. UV rays cause skin cancer,
cataracts and a weakened immune system in humans, which
means we can get sick easily. They can also affect algae,
which will disrupt the whole food chain.
What is the Hole in the Ozone Layer?
Ultra Violet Rays
In 2000, a hole in the ozone layer, nearly 30 million square
kilometres in size, (roughly as large as North America), was discovered.
In Antarctica, 65% of the ozone layer has already been destroyed. In other areas, the layer has
been destroyed by as much as 20%. The low temperatures of the polar regions speed up the
conversion of CFCs to chlorine.
The ozone layer is thinnest at the North and South Poles. There are many smaller holes in the
Arctic regions, causing UV rays to reach the heavily populated areas of Europe.
Nearly 5% of Earth is already not covered by the ozone layer. In addition, ozone levels are
dropping by 4% a year.
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Save Your Planet
Climate Change: The Ozone Layer
Hole in the Ozone Layer
Wikimedia Public Domain, created by NASA)
How is the Ozone Layer Being Destroyed?
In the 1980s, scientists discovered that the ozone layer was getting thinner. Since then
research has found that it is being destroyed by chemicals such as chlorine, fluorine and
bromine. One of the main ways that these reach the ozone layer is through
Chlorofluorocarbons (CFCs).
CFCs are gases used to keep things cold, like refrigerators and air conditioners. CFCs are also
used to make soap and foam, like fire extinguishers, as well as in pesticides, which are
sprayed on crops to stop insects destroying them. One of the main culprits of CFCs is spray
aerosols, like deodorants.
When they are used, CFCs are carried by the wind and find their way into the stratosphere.
Once there, they are broken down by UV light and then release chlorine, which breaks down
the ozone. One atom of chlorine can destroy 100,000 molecules of ozone.
In this way, the ozone layer is being destroyed and dangerous UV rays are now reaching
Earth.
CFCs in Fire Extinguisher
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CFCs in Aerosols
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CFCs in Pesticides
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Save Your Planet
Climate Change: The Ozone Layer
What Can You Do?
Encourage your parents and family to buy CFC-free or ozone-friendly products.
Remember the following if you play outside or do sport in the sun:
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Always wear sunscreen with a SPF of at least 30.
Cover your body and wear a wide-brimmed hat.
Do not play outside in the bright sun.
Use Sunscreen
Wear a Hat
What Has Been Done?
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1978 – Sweden was the first country to ban aerosol sprays.
1987 – The Montreal Protocol was signed by many countries to stop the production.
and use of substances that cause ozone depletion.
1996 – The United States and European countries banned the use of CFCs.
2003 – Scientists announced the depletion of the ozone layer is slowing down.
BUT….Some nations are still using CFCs!
Scientists predicted that ozone depletion peaked around 2010.
CFCs can last for up to 100 years in the atmosphere, so it will take another 50 years for
nature to repair the ozone layer and for it to return to the same levels as in the 1980s. Until
this time, we need to protect ourselves from the danger of UV rays.
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The Ozone Layer from Space
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