2. OZONE DEPLETION A Significant Environmental Issue

3. What is the Ozone Layer?  An important layer of O 3  Located in the stratosphere  Absorbs incoming ultraviolet rays from the sun  Acts as a sunscreen for the earth

4. What is Ozone Depletion?  Thinning and breakdown of the ozone layer

5. Causes of Ozone Depletion  Human (75 - 85%): –CFCs, HCFCs, carbon tetrachloride, halons –Methyl bromide, methyl chloroform  Nature (15 - 25%): –Methyl chloride, HCl

6. Impacts/Effects  Atmosphere –1% ozone depleted = 2% UV-B reaching earth’s surface –Climatic changes throughout the world

7. Impacts/Effects  Biosphere –Life cycle of plants will change –Harmful to planktons –Damage to lens, cornea, and retina –Causes skin cancer –60 million Americans  1 million will die skin cancer by 2075

8. Possible Solutions 1111987 –3–3–3–30 countries signed the Montreal Protocol 1111989 –M–M–M–Montreal Protocol finally takes effect DDDDevelopment of replacement for CFCs KKKKnowledge of current situation to everyone RRRRecycling old refrigerators

9. Ozone hole over Antarctic Composition: Nitric acid and ice crystals

10. References Warburton, P. (1999) Atmospheric Processes and Human Influence, Hong Kong: HarperCollins Publishers. Fisher, M. (1992) The Ozone Layer, New York: Chelsea House Publishers. Morgan, Sally. The Ozone Hole. Danbury, CT: Franklin Watts, 1999.