Using global climate models to evaluate environmental problems and potential solutions

1. PIK 21 May 2012 Using global climate models to evaluate environmental problems and potential solutions Ken Caldeira Dept. of Global Ecology Carnegie Institution for Science Stanford CA 94305 USA kcaldeira@carnegiescience.edu

2. PIK 21 May 2012 Exercises in undisciplined science Ken Caldeira Dept. of Global Ecology Carnegie Institution for Science Stanford CA 94305 USA kcaldeira@carnegiescience.edu

3. Science Values, morality Factual statements Prescriptive and normative statements

5. international v

6. Where did carbon come out of the ground to supply Germany’s CO2 emissions? Germany Russia Rest ofworld Norway Caldeira, Cao, and Bala, submitted

7. Where was CO2 emitted to support consumption in Germany? Germany China Rest ofworld Caldeira, Cao, and Bala, submitted

8. Where was the carbon extracted to supply consumption in Germany? Rest ofworld Norway Germany Russia Caldeira, Cao, and Bala, submitted

9. What is the international trade in carbon that is extracted from the ground in one country and emitted in another? Extraction  Production Davis, Peters, and Caldeira, PNAS 2011

10. Where was CO2 released in one country to produce products that were consumed in a different country ? Production  Consumption Davis, Peters, and Caldeira, PNAS 2011

11. What is the international trade in real or “embodied” carbon from the country of extraction to country of consumption? Extraction  Consumption Davis, Peters, and Caldeira, PNAS 2011

13. Infrastructural commitment to future climate change How much climate change are we committed to from existing CO2-emitting devices? Assuming normal device lifetime Steven J. Davis, lead co-conspirator

14. Infrastructural commitment to future climate change Approach Analyze existing stock of power plants, automobiles, etc, and estimate future emissions from these devices Apply emissions in a climate models Project future temperature change

16. Infrastructural commitment to future climate change Davis, S. J., K. Caldeira, and H. D. Matthews (2010) Future CO2 emissions and climate change from existing energy infrastructure,Science

17. Infrastructural commitment to future climate change Davis, S. J., K. Caldeira, and H. D. Matthews (2010) Future CO2 emissions and climate change from existing energy infrastructure,Science

18. Infrastructural commitment to future climate change A1G-FI A2 B1 Davis, S. J., K. Caldeira, and H. D. Matthews (2010) Future CO2 emissions and climate change from existing energy infrastructure,Science

20. Climate consequences of energy system transitions What the climate effects be of specific energy system transitions, taking into account energy-system life-cycle analysis data? Nathan Myhrvold, lead co-conspirator

21. Climate consequences of energy system transitions Approach Develop simple low-dimensional climate model -- radiative forcing from greenhouse gases -- time evolution of GHG concentrations -- thermal inertia of ocean -- radiative fluxes to space Represent GHG emissions during plant construction and operation Simulate energy system transitions

22. Climate consequences of 40 year transition of 1 TW coal system to alternative technologies

24. Climate consequences of afforestation / deforestation What are the combined biophysical and biogeochemical responses t large-scale afforestation or deforestation? GovindasamyBala, lead co-conspirator

25. Climate consequences of afforestation / deforestation LLNL coupled ocean-atmosphere carbon-climate model (NCAR PCM2, IBIS, modified OCMIP) GovindasamyBala, lead co-conspirator

26. With deforestation, CO2 is much higher but temperatures are slightly cooler Atmospheric CO2 Temperature Additional contribution from loss of CO2-fertilization of forests A2 Effect of loss of carbon from forests

27. Global deforestation experiment: net temperature change (CO2 + biophysical) A2

28. Boreal Temperature change predicted in latitude-band deforestation simulations Temperate Tropical

29. Predicted role of forests Tropical forests cool the planetTemperate (mid-latitude) forests do littleBoreal forests warm the planet

31. Does evaporating water cool global climate? George Ban-Weiss, lead co-conspirator

34. For each Joule of evaporated water, about ½ Joule additional gets to space Does evaporating water cool global climate? 1 W/m2 of evaporation leads to about ½ K cooling

36. Geophysical limits on wind power How much power could civilization get out of winds, considering only geophysical limits? Kate Marvel, lead co-conspirator

37. Geophysical limits on wind power Approach Perform simulations using NCAR’s CAM3.5 atmosphere model coupled to mixed-layer ocean with specified heat transport. 2⁰ lat x 2.5⁰ lon, 26 horizontal layers 100 year simulations, 60 years used

38. Geophysical limits on wind power Simulations Drag added to (i.e., momentum removed from)SL: bottom two Surface LayersWA: Whole Atmosphere Effective drag area from 1 to 104 m2 km-3

39. Geophysical limits on wind power Adisk = Disk area η = Fraction of kinetic energy (momentum) removed from flow

40. Geophysical limits on wind power Effective areaAeff = ηAdisk Adisk = Disk area η = Fraction of kinetic energy (momentum) removed from flow

41. Amount effective drag area and kinetic energy extracted

42. Amount effective drag area and kinetic energy extracted Global power demand

43. Climate effects: Temperature change Suggests civilization-scale zonal mean temperature changes of ~0.1 K

44. Climate effects: Precipitation change Suggests civilization-scale zonal mean precipitation changes of ~1 % 429 TW 428 TW

45. Atmospheric kinetic energy

46. Atmospheric kinetic energyproduction (loss) Slope = 0.8

47. Atmospheric polewardheat transport

48. Atmospheric polewardheat transport

49. Conclusions: wind power • Geophysical limits to global wind power greatly exceed global power demand. • Global power demand ~ 18 TW • Near surface winds > 429 TW • Whole atmosphere > 1873 TW • Climate effects of uniformly distributed wind turbines appear to be minor at civilization scale (0.1 K temperature , 1% precipitation)