Today, around 10% of the Earth’s surface is covered in ice. The Arctic and Antarctic regions are covered by a contiguous ice sheet – meaning, we are living in an ice age today.

But for most part of our planet’s history, the climate has been warm and equable, and even in the Arctic there was no ice cap. Contiguous ice sheets only exist during ice ages, which are rare and do not last long.

The diversity of life on Earth today is due to the last ice age.