There are too many answers for the cause of the Ice Age. The scientist Milutin Milankovitch was the first one to come with an answer in the twenties. He claimed that planet Earth was subjected to different amounts of solar energy at different times due to the difference in its cosmic movement. When this conclusion first appeared it seemed right as an ice age appears every 100,000 years approximately.
Milankivitch’s theory could not explain some variation in the ice age pattern. During the last 200 million years we lived without ice age. Recent studies focused on the greenhouse effect. But this may open the way for more questions that we could find an answer. What is the cause of fluctuations of CO2 without interference from human? The truth is we don’t know yet.