1. 03/02 Please, turn in your homework! “The World We Create” NATS 101 Section 6

2. UNIT 2: Global Warming, Natural or Man-Made?

3. The Global Warming Controversy Global warming – “is an average increase in the temperature of the atmosphere near the Earth’s surface.” (EPA) For sure you have heard about people having different views about “Global Warming:” Is it happening? What is causing it? What are its potential effects?

4. Is Global Warming a Fact? Observe the movie carefully:  Try to make a graph of temperature deviation  T from the average as a function of time.  Map the areas of the planet that have higher  T. Year TT 0

5. Is Global Warming a FACT? Important: Surface/troposphere  Warming Stratosphere  Cooling

6. Over Many Years What “causes” the changes?

7. Major Potential Causes What major factors may have an influence on the temperature of our planet? Which one dominates? Natural Human-induced Not sure Earth’s Orbit/Tilting Sun’s IntensityAmount of radiation Albedo Human Emissions Volcanic Eruptions Atmosphere’s composition Greenhouse gases Aerosols

8. Solar Activity oCoCW/m 2

9. Other Natural

10. Correlations

12. CO 2

13. CO 2 lagging? Claim: Although CO 2 may not initiate the trend, it sustains it and exacerbates it.

14. T rate increase

15. CO 2 Contributions Minor Contributions?

16. The Warming Process Increased CO 2 Warmer air Higher water vapor capacity More energy trappedHeating accelerated and more stored in the atmosphere! More energy trapped Heating accelerated and more stored in the atmosphere! Warming affects major natural cycles in our planet, such as the water cycle.

17. Precipitable Water

18. Estimates of changes in water vapor for the 20 th Century to be about 5% over the global oceans, and this indeed suggests a radiative forcing equivalent to that of carbon dioxide increases.

19. Each team will split into two groups: One group will support the position that human actions are the main contributing factor to global warming, while the other group will support the position that the cause of global warming is due to natural occurrences. Use information you learned today in class to support your arguments. At the end of the debate, take a poll to determine the overall team’s position on this issue. Mini-Debate