1. Changes to Radiative Forcing From: IPCC 2007 report

2. Climate Feedbacks Positive: a change in temperature (either positive or negative) that leads to a greater change in the same direction through a resulting change in a property of the system. Negative a change in temperature (either positive or negative) that leads to a change in a property of the system that acts to negate the original temperature change.

3. Positive Feedbacks Some important known feedbacks: Melting ice/ocean albedo albedo of ice with snow: ~0.95 albedo of sea water: 0.03 – 1.0 (depending on solar angle) Water vapor water vapor in atmosphere increases exponentially with temperature – Clausius-Clapeyron equation Ocean uptake of CO 2 solubility is inversely dependent on temp

4. Positive Feedbacks CO 2 partitions into water according to Henry’s Law: H = 3x10 -2 M/atm The ocean’s buffer system: pKa 1 = 6.1; pKa 2 = 9.2 The ocean’s pH is 8.2

5. Positive Feedbacks From the equilibrium expressions:

6. Positive Feedbacks From: Jacob

7. Negative Feedbacks Some important known feedbacks: CO 2 fertilization some plants sequester more CO 2 in a warmer CO 2 ‘rich’ atmosphere Water vapor – clouds an increase in atmospheric water vapor should lead to an increase in clouds and a higher planetary albedo

8. Reliability of Global Circulation Models From: IPCC 2007 report

9. Predictions From: IPCC 2007 report

10. Predictions From: IPCC 2007 report

11. Predictions From: IPCC 2007 report

12. Predictions From: IPCC 2007 report

13. Abrupt and Irreversible Change From: IPCC 2007 report ocean currentssea iceglaciers ice sheetsvegetationetc.

14. The Carbon Cycle From: IPCC 2007 report