1. May 10th, 2007 HW: Textbook- Read p. 535-539, #’s 1-4 Do Now: Do you think that we need Earth to be warmed? Aim: What is the greenhouse effect and how is it related to global warming?

2. YES! Otherwise it would be too cold to support life –No liquid water –Bacteria would not be able to function The SUN warms the Earth by a natural process: Do we need Earth to be warmed? THE GREENHOUSE EFFECT

3. The natural process in which Earth’s atmosphere traps heat by greenhouse gases THE GREENHOUSE EFFECT

4. Greenhouse Gases Trap energy (heat) from sun Most occur naturally in the atmosphere: 1.Water vapor --------> water cycle 2.Carbon Dioxide (CO 2 ) --------> respiration 3.Methane --------> where organic matter decompose with a lack of oxygen, plants, cattle during digestive process 4.Nitrous oxide --------> released by bacteria in soils and oceans 5.Ozone --------> reaction of ultraviolet rays with oxygen

5. What happens to the sun’s energy that heads towards earth? 1.Some is reflected back to space 2.Some penetrates the atmosphere and strikes the earth (otherwise the earth would be too cold) 1.Some of this energy is re-radiated back into space

7. So what’s the big deal? Excess (too much) greenhouse gases trap too much energy (heat) from sun An Enhanced Greenhouse Effect

8. Where does the excess greenhouse gases come from? Burning of fossil fuels –Releases CO2 and other greenhouse gases Deforestation –Less CO2 taken in by photosynthesis

9. How does this relate to Global Warming? Global Warming: increase in average global temperature Caused by enhanced (too strong) of a greenhouse effect

10. 1.What is the naturally occurring process of heating the earth called? 2.What traps the sun’s energy? 3.What are the naturally occurring greenhouse gases? 4.What creates excess greenhouse gases? 5. What is global warming? 6.What causes global warming? Greenhouse Effect Greenhouse gases Water vapor, CO 2, Methane, Nitrous Oxide, Ozone Burning of fossil fuels, deforestation Increase in average global temperature Excess greenhouse gases trapping sun’s energy

11. Greenhouse Effect Works