The Ozone Layer
© The GlobalEd 2 Project
Essential Questions
1. What is the ozone layer?
2. Why should I care about the ozone layer,
anyway?
3. What if the ozone layer did not exist?
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Enduring Understandings
1. The ozone layer refers to the ozone in
the stratosphere; where more than 90%
of the earth's ozone resides.
2. The ozone layer helps protects us.
3. The ozone layer absorbs much of the
sun’s uv light.
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Facts About Ozone Depletion
• Major Cause:
– Emissions of CFCs (chlorofluorocarbons); human
manufacturing
• Consequence:
– Increase in ultraviolet light from the sun
• Increase in skin cancers (carcinomas, malignant melanomas)
• Increased incidence of cataracts
• Impact on crops
© The GlobalEd 2 Project
CFC Facts
• Invented by Thomas Midgley in the 1920s
• Prior to the 1980’s, CFCs were used in:
– air conditioning/cooling units
– as aerosol spray propellants
– in the cleaning processes of delicate
electronic equipment.
© The GlobalEd 2 Project