1. Natural Mechanisms of Climate Change

2. How do we know about past climates?
Paleoclimatology- the study of the history of the earth’s climate
Using: ice cores, tree rings, and lake bottom sediment

3. External Forces – beyond earth
Solar Energy- changes in 3 ways:
1. Shape of earth’s orbit – sometimes circular, sometimes elliptical
2. Changes in earth’s tilt – currently at 23.5 degrees
Varies from degrees over 41,00 yr cycle
Smaller the tilt means less seasonal variation.

4. 3. Changes in earth’s spin – it wobbles sometimes.

5. Ocean, Atmosphere and Land Forces of Climate Change

6. Ocean Causes Changes Change climates along the coasts theyu flow
Change in temp
Change in the Great Ocean Conveyor

7. Volcanic Activity
Releases SO2 which forms sulfic acid and reflects sunlight
Releases huge amounts of ash and dust
-blocks the sun
Short tem

8. Atmospheric Albedo
The reflective property of the atmosphere (amount of sunlight atmosphere reflects)
An ↑ in clouds means an ↑ in reflection
A ↓ in clouds means a ↓ in reflection
The more sunlight that reaches Earth the temp ↑

10. Surface Albedo Earth’s reflective capacity
Includes land, snow, water, and ice
Ice and snow reflect, land absorbs
As ice and snow melt, less sunlight is reflected, more is absorbed, temp ↑

12. Asteroids and Meteoroids
If huge ones impact Earth, large amounts of dust and debris in atmosphere
May block out the sun
Leading theory on what killed the dinosaurs

13. Plate tectonics Changes where glaciers can form
Changes the flow of currents
Changes the climates on different continents
Redistributes the areas of absorption of solar radiation