Proposing a novel geological epoch, the Anthropocene, acknowledges the impact of anthropogenic change at the planetary level and suggests that the Holocene, which began approximately 11,700 years ago, has ended. This book examines how the Anthropocene Working Group (AWG), a third-level subordinate body within the International Union of Geological Sciences (IUGS), has led the debate about the Anthropocene concept among scientists and, significantly, within a wider global audience. For geoscientists, the focus has been on possible geological markers of a novel periodization in the Geological Time Scale (GTS) and the appropriate scientific methods to empirically validate a new geological epoch. However, scholars from other disciplines argue that the Anthropocene’s meaning extends beyond and differs significantly from geological markers, periodization, or time. The AWG evolved in this tension, seeking to make sense of the notion of a geological Anthropocene, drawing on various geoscientific and scholarly findings. We demonstrate how the AWG has become a focal point of a global debate that straddles the boundaries between academic disciplines and public perceptions of science.