According to the author, we are facing a radical transformation of our physical environment. This transformation is not limited to increased pollution or rising temperatures, but is part of a global crisis caused by human activity. For humanity to survive, radical social change and the replacement of fossil capitalism by an ecological civilization, eco-socialism, are necessary. Angus calls on 21st century Socialists to make the preservation of the Anthropocene their priority. The environ- mental crisis is the biggest crisis of our time and a global mobilisation is needed to preserve the Age of Man.