1. CHANGING ENVIRONMENT Stratospheric Pollution Ozone Layer Depletion
Greenhouse Effect

2. STRATOSPHERIC POLLUTION

3. WHAT CAUSES STRATOSPHERIC POLLUTION ?
Upper stratosphere consists of considerable amount of ozone, which protects us from the harmful UV radiations coming from the sun. Depletion of this protective layer causes stratospheric pollution.

4. BASIC MECHANISM

5. OZONE LAYER DEPLETION

6. WHAT IS OZONE AND OZONE LAYER?
Ozone (O3) is a highly-reactive from of oxygen.
Unlike oxygen (O2), ozone has a strong scent and is blue in color.
Ozone exists within both the tropospheric and stratospheric zones of the Earth’s atmosphere
In the troposphere, ground level ozone is a major air pollutant and primary constituent of photochemical smog
In the stratosphere, the ozone layer is an essential protector of life on earth as it absorbs harmful UV radiation before it reaches the earth.

7. CFC’s And Ozone Layer Depletion
Chlorofluorocarbons are created and used in refrigerators and air conditioners. These chlorofluorocarbons are not harmful to humans and have been a benefit to us. Once released into the atmosphere, chlorofluorocarbons are bombarded and destroyed by ultraviolet rays. In the process chlorine is released to destroy the ozone molecules

8. Destruction Of Ozone By Chlorine
Molecular oxygen is broken down in the stratosphere by solar radiation to yield atomic oxygen, which then combines with molecular oxygen to produce ozone. The ozone is then destroyed by chlorine atoms.

9. Ozone Destruction By UV Rays
UV radiation from the sun releases the radicals Cl and ClO.
Ozone is a highly unstable molecule so it readily donates its extra oxygen molecule to free radical species such as hydrogen, bromine, and chlorine.
These compound species act as catalysts in the breakdown of ozone molecules.

10. The Ozone Layer Depletion Process

11. Effects Of Ozone Layer Depletion
Damage to plant cell DNA molecules - makes plants more susceptible to pathogens and pests
Reductions in photosynthetic capacity in the plant - results in slower growth and smaller leaves
Causes mutations in mammalian cells and destroys membranes
Skin cancer
Premature aging (photo aging) of the skin (different from normal chronological aging)
Cataracts and eye disorders (corneal sunburn and blindness)
Immune system damage

12. THE GREENHOUSE EFFECT

13. WHAT IS GREENHOUSE EFFECT ?
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface, energy is transferred to the surface and the lower atmosphere. As a result, the temperature there is higher than it would be if direct heating by solar radiation were the only warming mechanism.

14. Greenhouse Gases
In order, the most abundant greenhouse gases in Earth's atmosphere are:
Water Vapors
Carbon Dioxide
Methane
Nitrous Oxide
Ozone

15. Example of the Greenhouse Effect
The Sun’s energy passes through the car’s windshield.
This energy (heat) is trapped inside the car and cannot pass back through the windshield, causing the inside of the car to warm up.

16. What is global warming?
Global warming is the current rise in the average temperature of Earth's oceans and atmosphere and its projected continuation. The scientific consensus is that global warming is occurring and was initiated by human activities, especially those that increase concentrations of greenhouse gases in the atmosphere, such as deforestation and burning of fossil fuels.

17. Effects of Global Warming
Rising Sea Level
Increased Temperature
Habitat Damage and
Species Affected
Changes in Water Supply

18. WHY IS GLOBAL WARMING HAPPENING?

19. Burning of Fossil Fuels
Pollution from coal, natural gas, and oil
Pollution from coal, natural gas, and oil
Pollution from coal, natural gas, and oil

20. What’s being done now to reduce our emissions?
Wind Power
Solar Power
Fuel-Efficiency

21. WHAT IS THE PROOF THAT GLOBAL WARMING IS TAKING PLACE?

22. Portage Glacier Alaska 1914 2004
Photos: NOAA Photo Collection and Gary Braasch – WorldViewOfGlobalWarming.org

23. Colorado River
Arizona
June 2002
Dec 2003

24. What can you do to solve the problem?

25. Simple Things To Do
Turn off your computer or the TV when you’re not using it. Take shorter showers. Heating water uses energy. Keep rooms cool by closing the blinds, shades, or curtains. Turn off the lights when you leave a room. Use compact fluorescent bulbs.

26. QUIZ TIME

27. GLOBAL WARMING WHAT ARE THE MAIN GREEN HOUSE GASES?
WHAT IS A GREEN HOUSE GAS?
WHAT ARE THE MAIN CAUSES OF GLOBAL WARMING?

28. OZONE LAYER DEPLETION WHAT IS OZONE LAYER AND WHY IT IS IMPORTANT?
HOW IS OZONE LAYER BEING DEPLETED?
HOW CAN WE PREVENT OZONE LAYER FROM DEPLETION?

29. STRATOSPHERE WHAT IS STRATOSPHERE?
WHAT IS THE IMPORTANCE OF STRATOSPHERE OR WHY DO WE NEED TO CONSERVE IT?

30. THANK YOU!! Rashi Saloni Tanvi Vidushi
Don't blow it - good planets are hard to find…!!!