The ice age is a period of time in Earth's history where large parts of the planet's surface were covered in ice and snow. It is generally agreed upon that there have been multiple ice ages throughout Earth's history, although the most recent one is the most well-known and affected the planet for tens of thousands of years. The ice age was a time of significant geological and biological changes, and its impact can still be felt today.

The most commonly discussed ice age is the one that affected much of the Earth's surface between 2.6 million and 11,700 years ago. Scientists refer to this as the Pleistocene epoch, and it is generally considered the most recent major glacial period. During this time, huge glaciers covered much of North America, Europe, and Asia. These glaciers were so massive that they caused significant changes in the planet's geography, shaping valleys, riverbeds, and other landforms as they moved across the surface.

The cause of the ice age is