Orbital Changes in Climate
Next we move from climate changes that conspire over several million years to “higher” frequency changes associated with orbital parameters. These Milankovitch cycles provide an explanation for glacial-interglacial periods that we’ve seen over the past three million years, further emphasize the importance of climate feedbacks and help to improve estimates of climate sensitivity. We can get a deeper understanding of “natural” climate variability to better answer the question of whether the changes in climate we’ve seen over the last 150yrs are natural or not by studying the more detailed paleoclimate data from the last glacial maximum 20kya up to present. Along the way be prepared for a bumpy ride.
Readings
Key Concepts
Definitions
Web links Abbreviated Lecture Notes
Next we move from climate changes that conspire over several million years to “higher” frequency changes associated with orbital parameters. These Milankovitch cycles provide an explanation for glacial-interglacial periods that we’ve seen over the past three million years, further emphasize the importance of climate feedbacks and help to improve estimates of climate sensitivity. We can get a deeper understanding of “natural” climate variability to better answer the question of whether the changes in climate we’ve seen over the last 150yrs are natural or not by studying the more detailed paleoclimate data from the last glacial maximum 20kya up to present. Along the way be prepared for a bumpy ride.
Readings
Key Concepts
- The cyclical nature of glacial-interglacials over the last million years can be primarily explained by what factors?
- How have monsoons changes in response to these variations?
- Is Earth currently at an interglacial optimum?
- Why are Milankovich cycles alone insufficient for explaining the magnitude of temperature change between glacial and interglacial periods?
Definitions
- Precession, Obliquity, Eccentricity
- Glacial and interglacial periods
- Radioactive decay and unstable isotopes
Web links Abbreviated Lecture Notes