Tony Robinson picks through the ruins of three great civilisations from the last 2,000 years to ask what made these civilisations more vulnerable to climate catastrophe than the ones who survived. In the jungles of Central America he investigates how decades-long drought brought the advanced Mayan civilisation to an apocalyptic end, resorting to human sacrifices to plead to their gods for salvation. Dr Joy Singarayer travels to the extraordinary landscape of Greenland to discover how the mini-Ice Age of the 13th century wiped out the 'advanced' Vikings, while their 'savage' Inuit neighbours developed new tools and strategies to stay alive. Meanwhile, in the deserts of America's southwest, Dr Jago Cooper investigates the climate crisis that made the Puebloan inhabitants of extraordinary cliff cities homeless 750 years ago.