How Many Ice Ages have There Been?

There have been at least five ice ages in the Earth’s history. The earliest occurred about 2.1 to 2.4 billion years ago. The next occurred 630 to 850 million years ago during the Cryogenian period. The Andean-Sharan, which was a minor ice age took place 430 to 460 million years ago, followed by the Karoo ice age 260 to 360 million years ago. Believe it or not, the Earth is actually in an ice age now that began about 2.58 million years ago and in which the last glacial period ended about 10,000 years ago.