Snowball Earth 700 Million Years Ago

A perfect combination of erupting volcanoes along with a rapid cooling effect may have caused the largest glaciation event in history - known as 'snowball Earth' - that covered our planet pole-to-pole in ice more than 700 million years ago, Harvard scientists say.

A perfect combination of erupting volcanoes along with a rapid cooling effect may have caused the largest glaciation event in history - known as 'snowball Earth' - that covered our planet pole-to-pole in ice more than 700 million years ago, Harvard scientists say.