North America was flooded and split apart into two pieces. The temperature then was more than fifteen degrees greater than the average temperature today. Scientists believe that the tilt of the earth's axis changes to tilt the opposite way every 10,000 years like a cycle. While going through this cycle it will change the climate of areas. Right now it is moving so that North America is going to be close to the sun in the winter.
Seasons become more extreme when the opposite happens.
This controls the cycle of ice ages. Volcanoes when they erupt, send clouds of dust into the air blocking sunlight. This would cool the earth off more. Oceans are known to absorb CO2 because of the ocean currents and the action of plankton. There is some evidence that there is naturally rapid climate change between each Ice Age, which confuses the whole global warming and idea.