1. The Ozone Layer
GOALS:
Explain how the ozone layer shields the Earth from harmful radiation.
Describe how CFCs are damaging the ozone layer.
What are impacts for a thinner ozone layer.

2. Ozone Layer Ozone Layer:
An area of the stratosphere with high concentrations of ozone gas
Acts like a sun screen blocking out UV rays
Ozone = O3
Good ozone vs. Bad Ozone

5. Ozone Depletion Chlorofluorocarbons (CFCs) Man-made chemical
“Miracle Chemical”
Damages the ozone layer
Takes a LONG time to get to ozone layer and destroys many ozone molecules

6. CFCs
Used for decades
Each CFC molecule can destroy 100,000 ozone molecules over decades

8. Ozone Hole
Antarctic Ozone Levels

9. Impacts of Thinning Ozone Layer
Damage to skin cells (including skin cancers)
Damage to eyes
UV Light damages DNA
Kills phytoplankton (single-celled organisms) which are the base of most ocean food chains
UV light damages crops

10. Wide Ranging Impacts

11. Protecting the Ozone Layer
Montreal Protocol: international agreement in 1987 to phase out CFC usage
Second conference in 1992 in Copenhagen
WHY WILL IT STILL BE A PROBLEM FOR MANY MORE DECADES?

12. Section Review
Explain how the ozone layer shields the Earth from harmful radiation.
Describe how CFCs are damaging the ozone layer.
What are impacts for a thinner ozone layer.
OZONE DEPLETION IS NOT THE SAME AS GLOBAL WARMING!!!
Exploring the Ozone Layer (video)