1. Start-Up: The hole in the ozone layer does not cause global warming. In fact, the hole in the ozone layer slows down global warming. Why is this a misconception some people have?

2. Greenhouse effect Greenhouse gases in the atmosphere trap heat that would otherwise be reflected back into space This is a natural process! Life on earth cannot exist without it!

3. Greenhouse gases: water vapor, carbon dioxide, ozone, methane

4. VENUS Extreme greenhouse effect!

5. Carbon cycle Process by which carbon moves from inorganic to organic compounds and back Matter and energy are not created nor destroyed! They are only converted from one form to another!

6. Humans have caused an increase in the amount of carbon released into the atmosphere Fossil fuels burned to run cars and trucks, heat homes and businesses, and power factories are responsible for about 98% of U.S. carbon dioxide emissions

7. Compare the increase in CO 2 output with this…

10. Monthly changes in atmospheric CO 2 concentration

11. 6CO 2 +6H 2 O  C 6 H 12 O 6 + 6O 2 Photosynthesis Trees act like carbon “sinks”, absorbing carbon from the atmosphere

12. Because trees are carbon “sinks”, when you cut them down, all the carbon they have absorbed get released into the environment

13. Without Human Activities Non-human events do not account for the trend

14. With Human Activities Both human and non-human events together account for the trend

15. What will the increasing level of carbon dioxide (a greenhouse gas) do to the greenhouse effect?

16. Predictions Differences are due to natural variability and human choices