1. Skeptics’ Arguments It’s the Sun

2. Solar Forcing

4. Radiative Forcing Estimates

5. Solar Forcing?

6. Radiative Forcing Estimates

7. IPCC, 2007 Fingerprint Analysis Black = Observed Gold = Human and Natural Forcings Blue = Only Natural Forcings

9. Skeptics’ Arguments It’s the Sun Natural Cycle

10. Ice Core Records

12. Source: Hansen, Clim. Change, 68, 269, 2005. Ice Core Records

13. Skeptics’ Arguments It’s the Sun Natural Cycle “Cooling”

14. US Temperature Record

15. http://data.giss.nasa.gov/gistemp/graphs/ Warming is Unequivocal

16. Source: Hansen, Clim. Change, 68, 269, 2005. Ice Core Records

17. Skeptics’ Arguments It’s the Sun Natural Cycle “Cooling” Others?

18. Bottom Line No credible alternative can explain the magnitude, time course, or spatial pattern of the warming that has actually occurred. Real debate has shifted from whether we are causing climate change to how severe its impacts will be and what we should do about it. Good sources: http://www.skepticalscience.org http://www.realclimate.org Naomi Oreskes’ Merchants of Doubt