Five times our world has stood on the brink of Armageddon - it's been incinerated, frozen, drained, flooded and smothered by poison gas. We are very lucky to be alive...
Delving into the deep history of mass extinctions, Brannen explores the five occasions when our world has stood on the brink of Armageddon, and provides a chilling warning of the unwelcome reprise we are heading towards.