This document summarizes information about ozone layer depletion. It discusses that the ozone layer protects the Earth from 95% of harmful UV radiation, but is being depleted by chemicals like CFCs. Main causes of depletion are CFCs, nitrogen fertilizers, and air/rocket transportation which release gases that break down the ozone. Consequences are increased skin cancer, eye cataract, and damage to animals. Control measures proposed are limiting driving/burning practices, using alternative refrigerants, and regulating rocket emissions.

1. Ozone layer depletion
Ravi Kumar GARRE

2. Contents covered
• Introduction
• Mechanism of ozone layer depletion
• Causes of ozone layer depletion
• Consequences of ozone layer depletion
• Control measures of ozone layer depletion

3. Ozone layer depletion
• Ozone layer is surrounded by earth about 15 to
40km above earth surface.
• The layer keeps/ reflects 95% of UV radiation from
sun which is harmful to life on earth.
• Ozone layer depletion refers to the thinning of the
ozone layer, which allows more UV radiation to
reach the earth’s surface.
• Ozone depletion occurs when destruction of the
stratospheric ozone is more than the production of
the molecule.

4. Ozone layer depletion
• These two reactions balance each other and
ultimately result in effective absorption of short
wave length UV radiation in stratosphere.
• This protects life on earth from harmful UV
radiations.

5. Ozone layer depletion
• 1971 – Harol Johnson (US Chemist) – NO is reason
behind Ozone’s depletion.
• 1985 – Farmen – the Ozone depleting at over
Antarctica.
• It was later realized that the main culprit of Ozone
depletion are chlorofluorocarbons.
• CFCs stay for a long period in stratosphere (65-38
years) depending on its type. During this period each
chlorine atom is capable of converting up to 10,000
molecules of ozone into oxygen.

6. Mechanism of ozone layer depletion

7. Causes of ozone layer depletion
1. Use of CFCs – reason for maximum damage of
ozone layer.
2. Nitrogenous fertilizers – release nitrous oxide
into atmosphere.
3. Air transport, rockets and space shuttles –
release oxides of nitrogen, carbon, sulphur,
hydrocarbons and particulate matter.
4. Nuclear tests
5. Some violent eruptions from sun also may be
responsible for producing ozone depleting
substances

8. Consequences of ozone layer
depletion
• Skin cancer and dangerous malignant
melanoma which occurs in the pigments of
body.
• Cataract formation in eyes
• Considerable damage to animals
• Lead to acid rain, photochemical smog, global
warming and climate change

9. Control measures
• Limit private vehicle driving
• Plant more trees and don’t burn plastics
• Use air conditioning equipment and
refrigerators that do not use CFCs and HCFCs
as refrigerants.
• Ban the use of dangerous nitrous oxide
• Developing stringent regulations for rocket
uses

10. Thank you