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Paleoclimate
Cretaceous Climate (144 to 65 million years ago)
While the dinosaurs were roaming the Earth, global temperatures were 8 to 15 deg C warmer than they are now. Tropical conditions existed as far north as Canada and Siberia! This warm period was followed by a gradual cooling, until 2.5 million years ago, when the current glaciation period began.
Why did the cooling occur? The underlying reason is plate tectonics, and their effects on the rock cycle and the carbon cycle.
Next page -> cretaceous climate, continued
Links and resources
Cretaceous Climate (144 to 65 million years ago)
While the dinosaurs were roaming the Earth, global temperatures were 8 to 15 deg C warmer than they are now. Tropical conditions existed as far north as Canada and Siberia! This warm period was followed by a gradual cooling, until 2.5 million years ago, when the current glaciation period began.
Why did the cooling occur? The underlying reason is plate tectonics, and their effects on the rock cycle and the carbon cycle.
- A decreased source of CO2, a greenhouse gas, because of plate tectonics.
- Removal of CO2 from the atmosphere and ocean because of the Himalayas.
- Reduced solar radiation at the South Pole because of Antarctica
- Reduced heat transport in the oceans because of North and South America
Next page -> cretaceous climate, continued
Links and resources
