“Sustainability” is a longstanding desideratum in environmental politics. Recent discussion posits that environmental upheavals mean the world is entering a new geological epoch, the “Anthropocene.” Those two notions—the ideal of sustainability and the proposal of the Anthropocene—offer sharply contrasting ways of imagining the current ecological crisis and possible responses to it. Both have significant antecedents in the earth sciences of the late eighteenth century. The former is typically attuned to the eighteenth century’s directional or cyclical theories of the earth; the latter is explicitly dependent upon the alternative historicist theories that came to prominence after the French Revolution. This talk will compare those ways of thinking about time and change in earth systems.