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Depletion of the Ozone Layer
Chlorofluorocarbons (CFCs) travel to the atmosphere where they catalyze the
breakdown of the ozone layer. Scientists have warned that even if action is taken quickly,
ozone depletion can be reduced, but not reversed for at least 100 years.
1. Ozone consists of three oxygen molecules (O3) is produced naturally by sunlight.
2. At ground level ozone is a pollutant, but in the stratosphere it forms a layer that
protects the earth from the harmful ultraviolet radiation from the sun.
3. Although ozone is just one layer of many in the atmosphere, it absorbs more
than 99% of the sun's ultraviolet radiation.
4. U.V radiation can cause sunburn and even skin cancer. It can also cause cataracts,
weaken the immune system, damage, kill micro-organisms on the ocean floor
(food for sea creatures), and decrease crop yields.
5. Chlorofluorocarbons CFC's have been shown to contribute to the greenhouse
effect. This would result in melting of ice caps, a rise in sea levels, and the
disruption of weather patterns.
6. Scientists had measured the amounts of ozone layer for many years; they
suspected it might be damaged by air pollution. Then in 1985, British scientists
announced that they had discovered a 30% decrease in the amount of ozone
over Halley Bay in the Antarctic.
(Also, satellite scientists had told their computers to regard any very low
readings as errors and therefore missed the hole.)
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CFCs are found in fridges, freezers and air conditioners and in some aerosol spray
and fire extinguishers. Plastic foams used for packaging and furniture can be made using
CFC's. In electronics factories, CFCs are used to clean the circuit boards that go into
televisions and computers. The CFCs then gradually drift up into the atmosphere.
They are safe at ground level, but are dangerous to the atmosphere.…read more
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FOR MORE INFO CHECK OUT MY CFC'S POWERPOINT PRESENTATION.…read more