1. AVG. 81.7 = 71.0%

2. Climate Change What is the greenhouse effect? What are some common green house gases? Where is the carbon and how much gets exchanged per year? Why do we not have a definitive answer about how hot we will get? Behaviour of complex systems (tipping points etc.)

3. Absorption by the Atmosphere http://en.wikipedia.org/wiki/Image:Atmospheric_Transmission.png

4. http://www.whrc.org/carbon/http://www.whrc.org/carbon/ (Woods Hole Research Center) Sediments and sedimentary Rocks could account for another 6x10 7 Petagrams! (www.physicalgeography.net/9r.html)

5. http://www.whrc.org/carbon/http://www.whrc.org/carbon/ (Woods Hole Research Center)

6. H&K Fig. 9.6: Feedback (positive and Negative) “Butterfly effect” in complex systems

7. CO 2 Concentrations and Temperature Change Note that total temperature change across several ice ages was only about 12 o C or about 22 o F.

8. Next summary will look at this: Robinson et al. J. Phys. Surg. 12, 79-90 (2007) These doctors say yes the warming is there, but claim that there is no evidence that the warming is anthropogenic. Why might you be skeptical of this article?

9. http://www.mardiros.net/atmosphere/atmosphere_structure.html 10 ppm ozone at ~ 50 km compared to 40 ppb ozone in the troposphere!

10. http://www.atm.ch.cam.ac.uk/tour/part2.html Ozone levels at Halley Bay station (Antarctica)

11. TOMS Satellite movie ( Total Ozone Mapping Spectrometer ) http://www.atm.ch.cam.ac.uk/tour/anim_toms.html

12. TOMS Satellite movie ( Total Ozone Mapping Spectrometer ) http://www.atm.ch.cam.ac.uk/tour/part2.html

13. Montreal Protocol (1987-9) http://en.wikipedia.org/wiki/Montreal_Protocol

14. Thermal Pollution Remember, all energy production eventually leads to thermal energy being dumped into the environment. I once had a colleague who claimed this was a strong argument against having unlimited cheap power (as might come from nuclear fusion). How does this compare to the problem of global warming (i.e. to the energy coming from the sun)?

15. Thermal Pollution: Local water sources

16. US Electrical power http://www.eia.doe.gov/fuelelectric.html Look at the text, which Shows an interesting Distinction between Utility producers and Non-utility producers In terms of this mix. (p 319)

17. Cooling towers

18. Basics of electricity There is a force other than gravity that acts “at a distance” (and is stronger). This force can be attractive or repulsive “Static Electricity” comes in two flavours; we call these positive and negative (like charges repel, unlike charges attract). At least some of the charges in metals are very mobile. The force is stronger if charges are closer. We can define a potential energy associated with the relative location of charges

19. Basics of electricity (cont.) The basics on the previous slide form the basis for all of our electrical technology! We measure charge in Coulombs (6.24x10 18 elementary charges) In electrical circuits, you have an “electromotive force” that provides the “push” (V: VOLTAGE, measured in VOLTS, a potential energy difference per unit charge 1 V = 1J/1 Coulomb) Moving charges carry the energy (I: current, measured in AMPS 1 A =1Coul/sec). Power = I V (1 watt = 1volt*1 Amp) The ratio of voltage to current is called the resistance of the circuit –OHM’s Law: V=IR (R measured in OHMS,  )

20. Batteries

21. Ohm’s Law The ratio of voltage to current in a circuit (or circuit element) is equal to the resistance of that circuit (or element) R = V / I V = I R I = V/R R is measured in OHMS (  ) 1  = 1V/1A.

22. Series and Parallel Circuits Series circuit: Current is the same in all elements (voltages add) Parallel circuit: Voltage is the same in all elements (Currents add)

23. US Electrical Power Generation

24. North American Power Plants http://en.wikipedia.org/wiki/Electric_power_transmission

25. US Electrical power http://www.eia.doe.gov/cneaf/electricity/epa/epa.pdf#page=15