It is the greatest climate disaster to have ever affected Earth – 650 million years ago, a cataclysmic ice age buried the planet beneath snow and ice, almost completely wiping out life and turning the world into one huge snowball.

Snowball Earth uncovers the story behind one of the most controversial theories in science today. To investigate, the programme travels the world to follow scientists scouring southern Australia, Nevada’s Death Valley and Alaskan glaciers for tantalising clues as to how our planet ran away into this doomsday scenario.