Step back in time by just 20,000 years and the world is a very different place. The Great Deep Freeze means that vast swathes of the northern hemisphere are covered by ice sheets, glaciers carve great valleys through the landscape, and continents me...
The last ice age ended only a few thousand years ago, but there were earlier periods when the entire world was frozen, periods now known as Snowball Earth. Episode 2 of Miracle Planet takes us back more than two billion years to this first ice age t...