In the Anthropocene, future people are more vulnerable to present people than ever before. This paper explores the idea that a required response to humanity’s changed circumstances is the introduction of a new category of crime into international criminal law: postericide. It discusses the ways in which a theory of postericide might be justified by reference to the moral imperatives embodied in international criminal law. And it explores the  traction and authority that a law of postericide has with respect to climate denial.