The OZONE!! By: The Green Squirrels Names of Team Members April 20,2005
Goals of this presentation Inform you of the ozone depletion of course!! –Background and History –Chemical Principles –Some Facts –HOW IT AFFECTS YOU!
Why Should You Know about the Ozone…. YOU…yes you…are one of the main factors in what is causing ozone depletion Because of ozone depletion you are susceptible to diseases such as cataracts, malignant melanoma, etc. Ozone depletion affects you and the world we live in
Location, Location, Location The Ozone (O 3 ) all around us 90% of the Ozone is contained in the stratosphere approx. 15 to 50 km above the earth
STRATOSPHERIC OZONE
What is this Ozone that I speak of? Studies of the upper atmosphere dates back to the 1800’s! 1930 – Sidney Chapman Multiple studies before 1970 do not take into account humans Click Me
What The Ozone Does Earth’s Natural Sunscreen UV-A: relatively harmless; causes tanning not burning UV-B: harmful; causes sunburn, skin cancer, and other disorders UV-C: extremely harmful; but almost completely absorbed by ozone
Causes Of Ozone Depletion Chlorofluorocarbons: refrigerants, solvents, foam blowing agents Methyl Chloroform: solvent Carbon Tetrachloride: industrial chemical Halons: fire extinguishing agents Methyl bromide: produce and soil fumigant
all uv-c and most uv-b never reaches the Earth’s surface
Ozone (O3) is a molecule made up of three atoms of oxygen (O)
high energy ultraviolet light = UV-C
O 2 + UV-C photon —› O + O O + O 2 —› O 3 (ozone) O 3 + UV-B photon —› O + O 2 O + O 3 —› O 2 + O 2 O 2 + UV-C photon —› O + O O + O 2 —› O 3 (ozone) O 3 + UV-B photon —› O + O 2 O + O 3 —› O 2 + O 2
CHAPMAN CYCLE
Causes Of Ozone Depletion Chlorofluorocarbons: refrigerants, solvents, foam blowing agents Methyl Chloroform: solvent Carbon Tetrachloride: industrial chemical Halons: fire extinguishing agents Methyl bromide: produce and soil fumigant
PROS and CONS of Ozone Depletion PROS There are no positives to ozone depletion. CONS Less plant production Less frogs and amphibians Increase of skin cancer and cataracts in humans
Ozone Depletion Since 1980
Affects on Human Health Ultra Violet – B radiation damages human skin Non-melanoma skin Cancer Cataracts
The Antarctic Ozone Hole Ozone levels have dropped 33% since 1975 Most depletion happens from September to December 3 – 5 degree increase in temperature predicted for 2020
Where did all this info come from?? Barid, Colin, Wendy Gloffke. Chemistry in Your Life. W.H. Freeman New York CIESIN Thematic Guides: Ozone Depletion and Global Environmental Change – Hardy, John T., Climate Change Causes, Effects, and Solutions. John Wiley & Sons West Sussex, England. Miller, Tyler. Environmental Science. Thompson Brook/Cole California The Ozone Hole – U.S. EPA: Ozone Depletion Science –