The document discusses ozone depletion and its causes. Ozone depletion is the gradual destruction of the ozone layer by chlorofluorocarbons (CFCs) released into the atmosphere. The ozone layer protects life on Earth from harmful ultraviolet rays. CFCs used in aerosol sprays, refrigerants, and other products damage the ozone layer when they reach the upper atmosphere. This depletion increases UV exposure and can harm plant life, animals, and humans through diseases. International agreements aim to reduce CFC usage and protect the ozone layer.

1. Ozone
Depletion

2. What is ozone depletion?
• The gradual destruction of the ozone layer
caused mainly by the release of
chlorofluorocarbons (CFCs) into the
atmosphere.
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3. Purpose of ozone layer
• Act as a shield around the Earth
• Protecting life on Earth from harmful
ultraviolet (UV) rays of the Sun
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5. Cause of ozone depletion
• CFCs have been identified as the main
cause of damage to the ozone layer.
• Chlorine contained in the CFCs are
destroying the ozone molecules in the
ozone layer.
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6. Sources of CFCs
• Aerosol spray
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7. Sources of CFCs
• Coolants in
refrigerators / air cons
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8. Sources of CFCs
• Styrofoam
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11. Consequences of ozone depletion
• Impact on animals and plants
– Damage plant tissues and destroy crops,
resulting in decline in food supply.
• Leading to famine
– UV rays kill plankton which food for many
marine animals
• Destruction of food chain and web
• Extinction of species
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13. Consequences of ozone depletion
• Impact on people
– Too much exposure to UV rays can cause disease
like cataract and skin cancer
– Weaken our immune system making us less resistant
to diseases
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14. Solution?

15. Measure to reduce ozone depletion
(international level)
• Sign international agreement to cut down
usage of CFCs
– Montreal protocol
– Kyoto protocol (reduce greenhouse gases)
• Reducing usage of CFCs products
– Stop buying products containing CFCs
– Disposal coolant in fridge & air con properly
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16. Measure to reduce ozone depletion
(national level)
• Ban use of CFCs by signing Montreal Protocol
– It is illegal to import products containing CFCs into
Singapore.
• New alternative to replace CFCs in
– Refrigerators
– Aerosol sprays
– Air conditioners
• All new cars in Singapore since 1995 are
equiped with CFCs free air conditioning systems
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17. Individual effort
• Use / buy products without CFCs
• When disposing products with CFCs in
them should inform waste company.
– These companies will take necessary actions
to prevent CFCs from escaping into the
atmosphere.
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