Ozone Layer Depletion
What is ozone?
Ozone is a gas made up of molecules that are formed by three oxygen atoms. Its molecule formula is O3. Ozone is formed when the sunlight hits oxygen molecules (O2) and breaks them up into individual atoms. These individual atoms then join up with O2 molecules and make O3, or ozone.
What is the ozone layer?
Way up high in the Earth's atmosphere, called the stratosphere, there is a fairly high concentration of ozone molecules that are formed when the sun hits oxygen molecules. This part of the atmosphere is called the ozone layer.
Ozone is formed in the atmosphere from oxygen molecules
Why is the ozone layer important?
Ozone molecules in the atmosphere provide us with important protection from the rays of the sun. Specifically, these molecules are good at absorbing certain ultraviolet rays that can cause sunburn and skin cancer.
How is the ozone layer getting damaged?
It turns out that certain types of molecules can cause a chemical reaction when they come in contact with ozone molecules. This causes the ozone to break up and become unable to absorb ultraviolet light. The main molecules that are destroying the ozone layer are called chlorofluorocarbons or CFCs.
Chlorofluorocarbons are a group of chemicals which are made up of only chlorine, fluorine, carbon, and hydrogen. They were first used as refrigerants to keep things cold. A lot of people considered CFCs miracle chemicals. Eventually they were used in a variety of products including air conditioners, spray cans, fire extinguishers, and in manufacturing foams.
Unfortunately, CFCs can eventually find their way into the Earth's atmosphere and the ozone layer. Once they get there they destroy ozone molecules and cause the ozone layer to become depleted or thinner.
CFCs Get Banned
In 1974 scientists Sherry Rowland and Mario Molina discovered the link between the depletion of the ozone layer and CFCs. CFCs became somewhat regulated, but it wasn't until 1987 that a treaty was formed called Montreal Protocol to try and stop the manufacture and use of CFCs throughout the world. CFCs were to be banned and completely eliminated in developing countries by the year 2000.
A hole in the ozone over the Antarctic
Effects on Health
Because CFCs last so long, the ozone layer will likely continue to thin for some time in the future. This will cause an increase risk of sunburn and skin cancer. Skin cancer can be very dangerous. For this reason you should always wear sunscreen to protect your skin when you are outside in the sun for a long time. Strong ultraviolet rays can also damage your eyes. You can protect them by wearing sunglasses.
What can we do about it?
There isn't much we can do about the CFCs that were released prior to the ban, but there are some things we can do:
- Old refrigerators - If you have a refrigerator made before 1995 it probably uses refrigerant made from CFCs. Get a new refrigerator and be sure to have the old one disposed of properly.
- Air conditioning - Old air conditioners, made before 1994, typically used a CFC called Freon. If you still have one of these, it's time to get rid of it and buy a new one. Even newer air conditioners use chemicals called HCFCs. Even though HCFCs are better for the ozone, they still contribute to the depletion, so try and use as little air conditioning as possible.
- Foam - A lot of foam products contain CFCs. Try and use different packing materials such as crumpled old newspapers.
- The word "ozone" means smelly in Greek because the gas has a strong odor.
- CFC molecules are highly stable and can last for up to 100 years. Unfortunately, this gives them plenty of time to find their way to the ozone layer.
- One chlorine molecule from a CFC can destroy up to 100,000 ozone molecules.
- Ultraviolet rays can also have bad effects on nature. They can kill plankton, which is a major source of food in the ocean's food chain.
- The ozone layer over Antarctica is very thin. It is sometimes called the "hole" in the ozone layer.
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