1. Do Now: Take out notebook Today is February 8, 2018
7.4 The Ozone Shield
Do Now: Take out notebook
Today is February 8, 2018

2. The Ozone Layer
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3. The Ozone Layer
The ozone is a form of oxygen.
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4. The Ozone Layer The ozone is a form of oxygen. It is O3, not O2.
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5. The Ozone Layer The ozone is a form of oxygen.
It is O3, not O2.
Ozone in the stratosphere absorbs ultraviolet rays from the sun.
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7. Ozone Eaters
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8. Ozone Eaters
1970s scientists began to worry about CFCs.
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9. Ozone Eaters 1970s scientists began to worry about CFCs.
Chlorofluorocarbons
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10. Ozone Eaters 1970s scientists began to worry about CFCs.
Chlorofluorocarbons
CFCs used in refrigerators and air conditioners.
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11. Ozone Eaters 1970s scientists began to worry about CFCs.
Chlorofluorocarbons
CFCs used in refrigerators and air conditioners.
Used in making Styrofoam, deodorants, insecticides and paints.
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12. UV light causes the CFC to break down, releasing a chlorine atom.
Chlorine goes to oxygen molecule.
The chlorine atom reacts with an ozone molecule to create an oxygen molecule and a chorine monoxide molecule.
The chlorine monoxide molecule then reacts with a another ozone molecule and one chlorine atom.
The chlorine atom can then break up another ozone molecule.
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13. The Ozone Hole
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14. The Ozone Hole
1985, British scientific journal reported that that Halley Bay, Antarctica recorded a reduction in ozone.
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15. The Ozone Hole
1985, British scientific journal reported that that Halley Bay, Antarctica recorded a reduction in ozone.
Reduction of 50% to 98%
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16. The Ozone Hole
1985, British scientific journal reported that that Halley Bay, Antarctica recorded a reduction in ozone.
Reduction of 50% to 98%
Ozone levels reduced since 1979.
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17. In these satellite images the Antarctic ozone amount is illustrated in red. Notice the total decrease in ozone from 1971 to 1998.
December 5, 2019
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18. Effects of Ozone Thinning
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19. Effects of Ozone Thinning
As the amount of ozone in the stratosphere decreases, more ultraviolet rays will come through.
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20. Effects of Ozone Thinning
As the amount of ozone in the stratosphere decreases, more ultraviolet rays will come through.
UV light damages DNA.
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21. Effects of Ozone Thinning
As the amount of ozone in the stratosphere decreases, more ultraviolet rays will come through.
UV light damages DNA.
UV kills single celled organisms such as algae.
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22. Effects of Ozone Thinning
As the amount of ozone in the stratosphere decreases, more ultraviolet rays will come through.
UV light damages DNA.
UV kills single celled organisms such as algae.
Can disrupt food web.
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24. Eyes
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25. Eyes
Cataracts can develop. Causing the lens to cloud up.
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26. Eyes Cataracts can develop. Causing the lens to cloud up.
Result: Blurred vision or blindness.
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27. Skin & Immune System
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28. Skin & Immune System
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29. Skin & Immune System
Faster aging, wrinkling and cancer.
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30. Skin & Immune System Faster aging, wrinkling and cancer.
Weaker immune response, making the body more susceptible to most diseases.
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31. Crops
December 5, 2019
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32. Crops
Interference with photosynthesis.
December 5, 2019
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33. Crops Interference with photosynthesis. Result: lower crop yield.
December 5, 2019
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34. Marine Life
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35. Marine Life
Ultraviolet kills phytoplankton near the surface and disrupts ocean food chain.
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36. Stopping the Ozone Eaters
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37. Stopping the Ozone Eaters
Chlorofluorocarbons are banned as per Montreal Protocol.
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38. Stopping the Ozone Eaters
Chlorofluorocarbons are banned as per Montreal Protocol.
It will take a few years for the stratospheric ozone.
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