1. Factor Influencing Climate Change Tectonics Ocean Circulation Patterns and the Thermohaline Cycle Orbital Forcing Mechanisms Atmospheric Variations

2. Climate Reconstruction Using Proxy Records JIce Cores JMarine Sediments JBanded Corals JPollen JTree Rings JLoess JSpeleothems JVarved Lake Sediments JPeat JGeomorphological Evidence JHistorical Evidence

3. Thermohaline Cycle wDriven by TEMPERATURE and SALINITY wShutdown of the system causes periods of cold -Shutdowns caused by: Freshwater pulses and changes in temperature which causes changes in density wThe “bipolar seesaw” theory -Shutdown of the thermohaline cycle causes cold in the Northern Hemisphere and warming in the Southern Hemisphere and vice versa.

4. Orbital Forcing Mechanisms  Obliquity - tilt of the Earth  Precession – Shape of the Earth Orbit about the Axis (think top)  Eccentricity – Shape of the Earth’s Orbit about the Sun

5. Orbital Forcing Mechanisms cont.  All factors influence insolation -How much of the radiation from the sun is being trapped within the Earth’s Atmosphere  Insolation decrease promotes cooling and ice sheet growth  Insolation increase promotes warmth and ice sheet melting

6. Atmospheric Variations VRising concentrations of Greenhouse gases –Methane, CO 2, water vapor, SO 4 VRises caused by: –Anthropogenic effects –Shutdown of Thermohaline Cycle –Orbital Forcing –Increased plant life (burial vs. growth)

7. Atmospheric Variations cont. VVolcanic Eruptions VAlbedo (positive feedback) VReflection of radiative heat

8. Final Thoughts  Dating is the most crucial aspect of climate reconstruction, but is the most difficult to perfect,  No one record, or person, has all of the answers. You need to put together all of the information, and ask questions, in order to understand picture being painted.