envcomm ozone depletion (uneditted)
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Ozone Depletion
Layers of the Atmosphere
Troposphere
Extends from the land or water surface up to an elevation of about five miles in the polar region.
Composed of water vapor and clouds
The layer where rainstorms are produced and airplanes fly.
Stratosphere
• 30 miles above the earth and gets hotter as you go higher
Mesosphere
• Extends another 20 miles and is characterized by a cooler temperature.
Ozone Layer
• Ozonosphere
• Hovers on top of the stratosphere
Ozone (O3)
• A strong smelling, slightly bluish gas.• Composed of threeoxygen atoms• Regarded as “the Jekyll and Hyde” of the
atmosphere.• About 90% of all ozone s located in the
upper regions of the stratosphere; the rest is at ground level and is responsible for warming the globe.
Depletion of Ozone Shield
• Ozone-depleting substances (ODS)
• Carbons
• Carbon tetrachloride
• Methyl chloroform
• Chlorofluorocarbons (CFCs)
CFCs
• Originally regarded as “wonder chemicals”• Colorless• Non-flammable• Non-corrosive• Non-toxic• Cool refrigerators and air conditioners• Clean delicate plastic foam• Used in home insulation• Propellant of aerosols
Cause of Depletion
• Once split apart into the stratosphere, CFC molecules pluck off one of the three oxygen atos in the ozone.
• A single chlorine atom can, over time, destroy more than 100,000 ozone molecules
• CFC Emissions Around the Globe• Western Europe and U.S contribute most og
the world’s CFC’s
Effects of Depletion
• If CFC usage continues unabated, more than 60 million addictional cases of skin cancer and one million additional deaths will take place by the year 2075.
• Make people more vulnerable to a variety of infectious diseases including malaria.
• Can cause 17 million cases of cataracts• UV-B radiation will disrupt the food chain• Destroy microorganisms necessary to maintain marine life.
Destroy photosynthesis and metabolism of plaktons and can cause mutation in some marine organisms
• Disrupt the Earth’s Climate.
Solutions to Ozone Depletion
• Ban the use and production of CFC’s, halons, and other ODSs • Require all service stations and auto repair shops to recycle CFCs• Prohibit the sale of new CFC-laden products-from refrigerators to dry-
cleaning solvents• Ban all cars equipped with CFC-using air conditioners• Prohibit the use of nearly all CFC’s in most industrial processes exept in
drug manufacturing medical devices and military specifications that require them,
• Ban the use of plastic foam for foof packaging.• Prohibit the use of building insulators with CFC compounds.• Require service station and auto repair shops to capture recycle Freon• Use Freon sucstitutes or alternati ves for CFCs• Reuse of CFCs by means of a recycling machine