1. Ozone & Greenhouse Effect

2. What is Ozone? Ozone is a molecule that occurs in the Stratosphere Ozone absorbs harmful UV rays from the sun O 3 + uv O 2 + O O 3 Ozone in the stratosphere protects us from harmful UV radiation

3. What’s the problem? In the 1970’s a compound called Chlorofluorocarbons (CFC’s) began to be used. CFC’s were used in refrigerators, propellants, aerosols, etc. It was thought that CFC’s were inert until scientists discovered…

4. CFC’s destroy ozone!

5. The ozone hole is a place in the lower stratosphere where ozone has been destroyed

6. Ozone Hole One molecule of CFC can destroy up to 100,000 molecules of ozone This has resulted in a hole in the ozone layer above Antarctica

8. Dangers of Ozone Depletion When ozone is depleted, harmful uv rays can get through the atmosphere This makes it much easier to get skin cancer

9. What has been done? Once it was proven that CFC’s were destroying ozone, scientists met in Montreal and made the Montreal Protocol The Montreal Protocol called for a ban of CFC’s and that production of CFC’s be stopped

10. The Greenhouse Effect Sun’s energy (aka- heat) gets trapped in the troposphere Some radiation that reaches Earth’s surface is absorbed. Some energy is reflected.

11. The Greenhouse Effect Reflected heat might get trapped by carbon dioxide, water vapor, or other gases. Trapped heat makes atmosphere warmer. Warm atmosphere reflects heat to Earth’s surface again!

12. Greenhouse Effect No greenhouse effect would mean colder than average temps. Too much, however, can cause a rise in average temps.

13. Global Warming Global warming IS the rise in average temps. Melting ice caps, rising seas, droughts

14. Global Warming Probable cause: carbon dioxide Where does it come from? Burning of fossil fuels (coal, oil, natural gas)

15. Greenhouse Gases The three types of greenhouse gases are water vapor, carbon dioxide and methane. They absorb heat energy from the sun in the form of infrared radiation. This keeps the earth warm enough for life to exist.