After nearly a decade overseas as a war reporter, 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 this finalist for the 2020 PEN/E.O. Wilson Literary Science Writing Award, 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 understand what the loss of ice means for nature and for humans. Encountering scientists, fishermen, and the last subsistence seal hunters of the Bering Sea, Jamail articulates the shared sense of urgency, while offering cogent reasons to cherish and protect our fragile planet.