This article examines an important theme in Cyprian’s address to the pagan Demetrianus, in which Cyprian responds to the accusation that the crisis of the mundus (‘world’) is evidence that the gods are angry that Christians have failed to worship them. Although Cyprian agrees, later in this treatise, that contemporary signs of crisis can be interpreted as a sign of God’s anger against humans in the present, he begins his treatise with another argument: that the visible signs of crisis in nature were in fact signs of God’s sentence of senescence and mortality on the natural world. I demonstrate, through comparisons with other of Cyprian’s works, that there is a subtle allusion in the address to Demetrianus to the precise moment of that sentence, after the fall in Eden; that is, the punishment of mortality was pronounced not just against sinful humans, but against the earth itself. I also show how this ancient scriptural aetiology for the failing world draws on the classical – especially Lucretian - tradition of the idea of the senectus mundi. Overall, the article aims to shift our understanding of the quality of Cyprian’s punitive eschatology in this treatise.