1. OZONE DEPLETION by
JAGTAP SANJAY B.
OZONE DEPLETION

2. Earth’s atmosphere Protective blanket surrounding the Earth.
Contain gases, dust particles, water vapor.
Saves life from hostile environment of outer space.
Composition of Atmosphere
Major component : Nitrogen , Oxygen, Water vapor
Minor component : Argon, Carbon dioxide.
Trace component : Neon, Helium, Methane, Krypton Nitrous Oxide, Hydrogen, Xenon Ozone, Ammonia.
Total mass of the Atmosphere is approximately 5*1015 tons, which is roughly one Millionth of the Earth’s total mass.

3. Structure of Atmosphere
Troposphere
Stratosphere
Mesosphere
Thermosphere

4. Structure of Atmosphere

5. OZONE LAYER
The word Ozone is derived from Greek word OZIN meaning pleasant gas.
In Stratosphere it is found at altitude 15 to 50 km.
Percentage of Ozone in Atmosphere %
Sea level ozone is 0.5 PPM
Color of Ozone is Blue.
Out of one Lakh Molecule only one molecule of Ozone is in the Atmosphere.
Ozone is one form of Oxygen, but opposite to Oxygen, Ozone is poisons gas.
Unstable in nature

6. Ozone (O3) is formed by one Molecule of Oxygen with one Atom of Oxygen
Ozone (O3) is formed by one Molecule of Oxygen with one Atom of Oxygen. Called as natural umbrella, prevents the entry of harmful Ultra Violet rays.

7. 1 11
111 1V 1V

8. Good Ozone
Bad Ozone
Above the elevation of 15 to 50 km in the stratosphere layer present Ozone absorbs ultra violet rays coming from Sun and protects the Earth this is good Ozone.
In Troposphere near the surface of earth due to anthropogenic activities of mankind increase in percentage of
Nitrogen oxide(N2 O), Hydrocarbon(HC). In the presence of sunlight Ozone produce naturally on the Earth surface causes harmful ill effects. This is bad Ozone

10. Global study of Ozone depletion
Conclusion of Russian scientists: Explosion due to nuclear tests carried out by Russia, USA and France emitted Nitrous oxide in Atmosphere causes Ozone depletion. (Molina and Roland 1974)
Theory by Ben Ezence : Scientist from Canada, carried out 12 years study of Atmosphere from 1975 to stated that CFC is responsible for Ozone depletion. He also study Earths Heat Budget and stated that Earth absorb 0.1 % more energy from solar radiation.
Conclusion by NASA : observations obtained from various satellites conclude that up to year 1986, Ozone is depleted by 50%

11. Observations by National Science Foundation : In year 1985 American satellite ‘NIMBUS-7’ observe big hole to Ozone layer on Antarctica. The area is near about area of USA. % is greater in the months from August to October.
Conclusion by UNO : According to Environmental programme run by UNO conclude that from the total Ozone depletion 90 % done by CFC, Chlorine, and Bromine.

12. Process of Ozone depletion
Natural process :
A The UV rays coming from the Sun absorbs by the Ozone layer and undergoes photochemical reaction. In this reaction ozone is dissociated in to molecular Oxygen and Oxygen atom.
O3 UV rays O2 + O
This loss of Ozone is automatically compensated by the formation of Ozone in the Atmosphere.
O O O3
O2 + O O2 + O O2 + O
O2 + O O3

13. B Nitrogen oxide is formed by conversion of Nitrogen due to solar radiation. Photochemical reaction by Nitrogen oxide depleted large amount of Ozone.
Man made process :
Modern ways of life of human being lead to depletion of Ozone umbrella. This called anthropogenic process.
Nitrogen oxide
Sulphate aerosols
CFCs

14. Causes of Ozone depletion
Natural causes
Man made causes
Volcano eruption
Decomposition
High frequency of sunlight
Chemical fertilizers
Rocket
Space shuttle
supersonic Aeroplanes
Atomic explosion
Burning of fossil fuel
Halon gas used in fire extinguishers
Cooling system(CFCs)

15. Effect of CFCs
Industrial pollution
Industrial pollution

16. Supersonic aero plane
Atomic explosion
Atomic explosion

17. Projecting Space Shuttle

19. HOLE IN THE OZONE LAYER AT POLE.

20. Harmful effects of Ozone depletion
Skin, breast, blood cancer
Kill phytoplankton
Sun burn
Asthma
DNA breakage
Change in Ecosystem
Reduction in Photosynthesis
Global warming
Melting of ice belts
Increase in sea level

21. Control of Ozone depletion
The CFCs should be substituted with harmless chemicals like Hydro Chloro Fluoro Carbon.
Complete ban on Halon.
Use of compost fertilizer.
Ban on atomic explosion.
Plantation and conservation of trees.
Public awareness programme.
Reduce air pollution

22. Montreal Protocol
11 developed countries participated in this meeting on Ozone depletion in Canada on 16th Sept 1987.
They decided that from 1st Jan 1989, use of CFC shall be initiated with imposing complete ban by 2000.
This will lead to 20% less production of CFCs.
India signed the treaty in 1992.

23. 16 September was celebrated as INTERNATIONAL OZONE DAY

24. Thank you…!