1. Climate Systems Chapter 15

2. Clicker Question What is the approximate CO 2 content of the atmosphere? –A. 0.004% (40 ppm) –B. 0.04% (400 ppm) –C. 0.4% (4000 ppm) –D. 4% (40,000 ppm) –E. 40% (400,000 ppm)

3. Clicker Question What is the approximate CO 2 content of the atmosphere? –A. 0.004% (40 ppm) –B. 0.04% (400 ppm) –C. 0.4% (4000 ppm) –D. 4% (40,000 ppm) –E. 40% (400,000 ppm)

4. Clicker Question The CO 2 content of the atmosphere has increased by more than 20% in the past 50 years. –A. True –B. False

5. Clicker Question The CO 2 content of the atmosphere has increased by 19% in the past 50 years. –A. True –B. False

6. Systems? What is a system? Geologic phenomena are complex. All processes are related to, and interact with, other processes. So it is useful to think of geologic processes as systems or cycles.

7. Earth Systems Earth Interior Systems –Mantle Convection and Plate Tectonics –Core Convection and Magnetic Field –Rock Cycle (weathering & metamorphism) Atmospheric/Biospheric Systems –Hydrologic Cycle –Ocean Cycles (Circulation and El Niño) –Carbon Cycle (CO 2 in atmosphere) –Oxygen Cycle

8. Earth Interior Systems Rock Cycle –Igneous-Weathering-Sedimentation- Metamorphism Mantle Cycle –Mantle Convection, Crust Formation, and Subduction = Plate Tectonics –Water Cycling Core Convection –Magnetic Field - Ozone shield

9. Earth Interior Systems: Deep Water Cycle Ocean crust hydrates on ocean bottom. Crust and lithosphere subduct. >90% of water is returned at arc volcanoes 1 to 10% of this water goes deep. This water is returned at mid ocean ridges.

10. Earth Interior Systems: Deep Water Cycle 0.2% H 2 O in subducting crust is sufficient to recycle the oceans once in 4 Gy. Oceans (0.025% of Earth mass) is maintained by a deep cycle of H in high pressure minerals. H solubility in rock is responsible for the style of plate tectonics.

11. Atmospheric/Biospheric Systems: Human Impact Hydrologic Cycle –Evaporation - Transport - Precipitation - Flow Ocean Cycles –Global Circulation & El Niño Carbon Cycle (Greenhouse Gas) –CO 2 - Photosynthesis - Carbon - Carbonates Oxygen Cycle –O 2 in atmosphere is biogenic –Incompatible with methane (CH 4 )

12. Hydrologic Cycle in 1000’s km 3 /y

13. Carbon Cycle: Natural Sources and Sinks

14. Carbon Cycle: Anthropogenic

15. Carbon Cycle CO 2

19. Carbon Cycle

21. Warming Sea Level Rise –Thermal Expansion of water –Melting Glaciers Increased Storm Intensity

22. Warming: Vulnerable US Cities New Orleans Houston Corpus Christi Mobile Orlando Miami

23. Climate Cycles: Eccentricity

24. Climate Cycles: Tilt

25. Climate Cycles: Precession

26. Continental Drift and Ocean Circulation

27. Ocean Cycle: El Niño

28. Continental Drift

29. Past Climate History 18 O/ 16 O Variation in Ice Cores –Oxygen isotopes are fractionated by evaporation and precipitation. –The vapor prefers the lighter isotope. –Cold global temperatures deplete 18 O in ice and enrich it in ocean water. –Isotope variation can be measured in ice cores and in ocean sediments. CO 2 variation can be measured in gas bubbles in ice. Both methods provide evidence of large variation in global temperatures

30. Atmospheric/Biospheric Systems: Human Impact Hydrologic Cycle –Evaporation - Transport - Precipitation - Flow Ocean Cycles –Global Circulation & El Niño Carbon Cycle (Greenhouse Gas) –CO 2 - Photosynthesis - Carbon - Carbonates Oxygen Cycle –O 2 in atmosphere is biogenic –Incompatible with methane (CH 4 )

31. Earth Systems Terms Carbon Cycle Rock Cycle Mantle Cycle Greenhouse Gas El Niño La Niña

32. Climate Learning Goals Atmosphere is in equilibrium with surface Cycles and Systems Hydrologic Cycle: Surface, shallow, deep Ocean circulation: heat transport Carbon Cycle: Sources and sinks Oxygen Cycle: Where does it come from? Rock Cycle: weathering, transport.

33. Climate Learning Goals What is a greenhouse gas? How does it trap heat? How much CO 2 do we have now? What are main sources and sinks? Do we have a record of past CO2? Do we have a record of Earth temperatures?

34. Next Chapter 16 Weathering, Erosion, Mass Wasting Does weathering of rock remove or add CO 2 to the atmosphere? –A. Adds –B. Removes –C. No effect on CO2

35. Next Chapter 16 Weathering, Erosion, Mass Wasting Does weathering of rock remove or add CO 2 to the atmosphere? –A. Adds –B. Removes –C. No effect on CO2