1. CLIMATE
An Abrupt Climate Change Scenario and Its Implications for United States National Security (Pentagon Report, 2003). Global warming “should be elevated beyond a scientific debate to a US national security concern... future wars will be fought over the issue of survival rather than religion, ideology or national honour.”
"Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems." IPCC, 5th intergovernmental report
Understanding climate matters….

2. I. Large Scale Determinants A. Solar Radiation
CLIMATE
I. Large Scale Determinants
A. Solar Radiation
1. Average Radiation Budget
- Solar Constant = 2 calories/cm2/min
- 50% is reflected, absorbed, reradiated (Most ultraviolet light is reflected/absorbed) by the atmosphere
- on average, 1 cal/cm2/min strikes earth.
(but this varies dramatically, as we will see…)

3. - 50% is reflected, absorbed, reradiated (Most ultraviolet light is reflected/absorbed)
Difference between red and yellow is incoming radiation absorbed by atmosphere

4. YAY OZONE!
CO2 fills ‘window’ in H2O absorbance
ABSORBANCE
Greenhouse effect

5. A. Solar Radiation 1. Average Radiation Budget
2. Local Radiation Budget – Angle of incidence (latitude and season)
Goes through more atmosphere
Less energystrikes/unit area (since it is spread over more area)
3) More is reflected off surface; a
lower percentage of what
strikes/unit area is absorbed

6. A. Solar Radiation 1. Average Radiation Budget
2. Local Radiation Budget – Angle of incidence (latitude and season)

7. B. Effects on Atmospheric Circulation
LOW ENERGY
LOW ENERGY
HIGH ENERGY

8. HIGH ENERGY
LOW ENERGY

11. As air rises:
- decrease pressure
- increase volume
- decrease energy/unit volume
- decrease temperature

12. As air rises:
- decrease pressure
- increase volume
- decrease energy/unit volume
- decrease temperature
“Adiabatic cooling”
Decrease temp, increase tendancy of water vapor to condense

13. PV = nRT As air rises: - decrease pressure - increase volume
- decrease energy/unit volume
- decrease temperature
“Adiabatic cooling”
Decrease temp, increase tendancy of water vapor to condense
PV = nRT

14. As dry cold air falls:
- increase pressure
- decrease volume
- increase energy/unit volume
- increase temperature
“Adiabatic warming”

15. 30oN 30oS As dry cold air falls: - increase pressure - decrease volume
- increase energy/unit volume
- increase temperature
“Adiabatic warming”
30oN
Increase temp of this dry air, evaporate water off surface
30oS

16. 30oN 30oS HOT, DRY, DESERTS TROPICAL RAINS at solar equator

17. 30 N
30 S

18. Latitude of solar equator drive seasonal rainy seasons in tropics

19. Three cycles in each hemisphere:
Hadley
temperate (Ferrel),
polar

20. Transfer of energy from equator to poles
(“Why are global warming’s greatest effects at the poles, not in raising the temperature of the tropics?)

21. C. The Coriolis Effect
- Pattern of air movement along the surface of the earth…

22. C. The Coriolis Effect
Pattern of air movement along the surface of the earth…
- conservation of momentum east
- speed relative to Earth changes
(treadmill analogy)

23. C. The Coriolis Effect

24. D. Effects on Ocean Circulation

27. E. Long-Term Effects
1. ENSO (El Nino Southern Oscillation)

28. E. Long-Term Effects 1. ENSO (El Nino Southern Oscillation)
“upwelling” of cold, nutrient-rich water from depth feeds coastal productivity of fish
“upwelling” stops, fish populations (and fisheries) crash

29. E. Long-Term Effects
1. ENSO (El Nino Southern Oscillation)

30. E. Long-Term Effects 2. Younger Dryas
- Dramatic cooling of northern Europe 11,000-13,000 years ago, correlating with the melting of the Laurentian Ice Sheet in North America.
- Fresh water formed a lens on surface; deflecting Gulf Stream to the east at a much lower latitude, starving Europe of the heat transferred by the Gulf Stream.

31. F. Difficulties in Modeling Global Climate
1. Positive Feedback Loops

32. F. Difficulties in Modeling Global Climate
1. Positive Feedback Loops

33. F. Difficulties in Modeling Global Climate
1. Negative Feedback Loops