1. Introduction to Geoengineering for Ecologists Ken Caldeira Carnegie Institution Dept of Global Ecology kcaldeira@carnegie.stanford.edu Ecosystem Impacts of Geoengineering Workshop Scripps, 31 Jan 2011

2. Reuters: David Gray

3. www.sit.ac.nz

5. Solar Radiation Management options Carbon Dioxide Removal options

6. Desire for improved well- being Demand for goods and services Demand for energy Impacts on humans and Climate change & ocean CO 2 emissions CO 2 in ecosystems acidification atmosphere Conservation Efficiency Low-carbon energy Carbon dioxide removal Adaptation Climate engineering

8. Temperatures continue to increase throughout this century in every plausible emissions scenario IPCC TAR There is no practical way for emissions reduction to reduce temperatures this century

9. Volcanoes caused global cooling by putting dust in the stratosphere Soden et al., 2002 Mt. Pinatubo

11. Temperature effects of doubled CO 2 Δ Temperature Statistical significance Caldeira and Wood, 2008

12. Temperature effects of doubled CO 2 Δ Temperature Statistical significance Caldeira and Wood, 2008 with a uniform deflection of 1.84% of sunlight

13. Precipitation effects of doubled CO 2 Caldeira and Wood, 2008

14. Temperature effects of doubled CO 2 Caldeira and Wood, 2008 with a uniform deflection of 1.84% of sunlight

15. Zonal average precipitation and temperature Caldeira and Wood, 2008

16. Cao et al, in prep. In HadCM3L, a coarse-resolution atmosphere-ocean GCM, perform outer product of (27) simulations starting from -- 3 different initial conditions (1xCO2, 2xCO2, 4xCO2) -- 3 different CO2 levels (1xCO2, 2xCO2, 4xCO2) -- 3 different solar intensity levels (-2CO2eq, normal, +2CO2eq) Perform linear regressions to separate dependencies on -- global mean temperature, -- CO 2 -concentration, and -- solar intensity.

17. C – response per CO 2 -doubling S – response per equiv. solar increase T – response per  C warming Cao et al, in prep.

18. C – response per CO 2 -doubling S – response per equiv. solar increase T – response per  C warming Cao et al, in prep.

19. C – response per CO 2 -doubling S – response per equiv. solar increase T – response per  C warming Cao et al, in prep.

20. Main effects - High CO 2 - Lower temperature Secondary effects - Changes in PAR - Changes in precip/evap Not considered - Changes in UV - Diffuse radiation - Everything else

22. TreesCrops Grasses C4 Positive down

24. Mt. Pinatubo and global ozone Mt. Pinatubo

27. Concluding suggestions Consider consequences if people are deploying measures thoughtfully Compare “geoengineered” state to both “natural” state of the system and the perturbed state in the absence of “geoengineering”