This Very Short Introduction explains the science behind the Anthropocene and the many proposals about when to mark its beginning: the nuclear tests of the 1950s? The beginnings of agriculture? The origins of humans as a species? Erle Ellis considers the many ways that the Anthropocene's "evolving paradigm" is reshaping the sciences, stimulating the humanities, and foregrounding the politics of life on a planet transformed by humans. The Anthropocene remains a work in progress. Is this the story of an unprecedented planetary disaster? Or of newfound wisdom and redemption? Ellis offers an insightful discussion of our role in shaping the planet, and how this will influence our future on many fronts.