After nearly a decade overseas as a war reporter, the acclaimed journalist Dahr Jamail returned to America to renew his passion for mountaineering, only to find that the slopes he had once climbed have been irrevocably changed by climate disruption. In response, Jamail embarks on a journey to the geographical front lines of this crisis - from Alaska to Australia's Great Barrier Reef, via the Amazon rainforest - in order to discover the consequences to nature and to humans of the loss of ice.