2. GLOBAL WARMING AND OZONE DEPLETION

3. Agenda  Continuation from yesterday  Independent Practice  Articles & Follow Up Questions

4. The Greenhouse Effect  The gases in the atmosphere that absorb the reradiated infrared radiation are known as greenhouse gases.  Water vapor, carbon dioxide, and methane are some examples.

5. The Greenhouse Effect  The energy from the absorbed radiation heats the gases in the air. These gases form a “blanket” around Earth that holds heat in the atmosphere.  The process by which gases hold heat in the air is called the greenhouse effect.

6. The Greehouse Effect

7. The Greenhouse Effect  In a greenhouse, the glass allows short wavelength radiation to enter,  but does not let long wavelength (infrared) radiation to escape.

8. Greenhouse Effect

9. Analogy…foiling hot food

10. What does the Greenhouse Effect do?  The greenhouse effect is a natural process that keeps Earth’s atmosphere at a temperature that is comfortable for most living things.  Were it not for the greenhouse effect, Earth would be approximately 33  C colder than it is.

11. Global Warming  Human activities that add greenhouse gases to the atmosphere may be warming Earth’s atmosphere.  The burning of wood, coal, oil, and natural gas adds carbon dioxide to the air.  The increased carbon dioxide can trap heat and the result could be global warming.  Global warming is a gradual increase in the temperature of Earth’s atmosphere.

12. Effects of Global Warming

13. Ozone Depletion FILTER

14. Ozone Depletion  In the 1970’s, scientists noticed that the ozone layer over Antarctica was growing thinner.  Chemicals produced by humans have been damaging the ozone layer.  The main cause of ozone depletion is a group of chlorine compounds called chloroflourocarbons, or CFCs.  CFCs are destroying the ozone layer

15. Ozone Depletion

16. Ozone Depletion Effects  Skin cancer increases  Sun burns  Eye problems  Malaria  Infectious Disease

17. Independent Practice  Complete practice questions  Read articles 1 and article 2  Answer questions that pertain to each article  HOMEWORK IF NOT FINISHED IN CLASS!