1. “Life’s Support System Depletion”
Ozone
Layer
Depletion
“Life’s Support System Depletion”

2. Outline of Presentation
What is the Ozone layer?
How is ozone created and destroyed?
What is the Ozone hole?
What are the causes of Ozone Depletion?

3. Outline of Presentation
What are Ozone Depleting Substances?
Effects of the depleting Ozone to humanity and all living things.
Impacts of the Ozone Layer depletion to the Earth.
How can the Ozone layer be saved?

4. What is Ozone Layer?
The Ozone Layer is a thin, fragile shield that envelops the entire earth which efficiently and effectively filters and screens almost all of the harmful ultraviolet rays.

5. Ozone is a gas that is naturally present in the atmosphere.
air molecules
Ozone is a gas that is naturally present in the atmosphere.
It is a molecule made up of three oxygen atoms.
It’s chemical symbol is O3.

6. The Atmosphere
Earth’s atmosphere is divided into four layers with different elevation and temperature profile:
Troposphere
Stratosphere
Mesosphere
Thermosphere

7. THE GOOD AND BAD OZONE

8. The Solar Radiation
The Earth’s atmosphere is exposed to radiation from the sun. Energy is transferred from the sun to the earth in the form of electromagnetic energy. Electromagnetic energy can be divided into spectrum, in which protons that transfer energy have both a wavelength and energy level.
This radiation includes ultraviolet, visible and infrared radiations.

9. There are three categories of UV:
UV-A: Most UV-A is able to reach the earth’s surface.
UV-B: 90% of UV-B is blocked off by the ozone layer.
UV-C: 100% of UV-C is blocked off by the ozone layer.

10. HOW IS OZONE CREATED AND DESTROYED?

11. HOW OZONE IS CREATED IN THE STRATOSPHERE7

12. How ozone is naturally destroyed in the Stratosphere
UV radiation strikes ozone molecule…
… releasing one oxygen atom O
How ozone is naturally destroyed in the Stratosphere

14. 3
What is the
The depletion or the loss of the blocking effect of the ozone layer against ultraviolet rays is what we call the OZONE HOLE.

15. What causes the ozone layer to deplete?

16. The Ozone Depletion Degradation of the Ozone Layer.
When even a small amount of ozone layer is lost, more ultraviolet light from the sun can reach and destroy the Earth.
Caused by the chemical reaction involving chlorine and bromine which are also called Ozone Depleting Substances (ODS).

17. OZONE DEPLETING SUBSTANCES (ODS) AND THEIR USES
CHLOROFLUOROCARBONS or CFCs
HALONS
Contain at least one bromine atom
Halons are primarily used in fire extinguishers
Simple chemicals containing chlorine, fluorine and carbon.
CFCs are used in refrigerators, air-conditioners, spray cans, solvents, foams, other application.

18. OZONE DEPLETING SUBSTANCES (ODS) AND THEIR USES
CARBON TETRACHLORIDE and METHYL CHLOROFORM are used as solvents.
HYDROBROMOFLUOROCARBONS (HBFCs) are used in fire extinguishers.
HYDROCHLOROFLUOROCARBONS (HCFCs) were developed as the first major CFC replacement .

19. OZONE DEPLETING SUBSTANCES (ODS) AND THEIR USES
METHYL BROMIDE (CH3Br) is used as a fumigant and in quarantine treatment.