Formalizing the Anthropocene: an interplay between normative knowledge-making and societal norm-making

How, and to what extent, can societal norms legitimately enter scientific knowledge-making, or can science intervene in societal norm-making? This question has become a key matter in defining and studying the Anthropocene as a new geological epoch. This paper aims to enrich the discussion by examining how two kinds of norms – one operating primarily within the boundary of science and the other originating from broader societal concerns – came to intersect in the debate over formalizing the Anthropocene as a new geological epoch. The first part of the paper traces the historical development of the GSSP practice as the central normative backbone of modern chronostratigraphy. Drawing on archival documents from the International Subcommission on Stratigraphic Classification (ISSC), in which the concept of GSSP was first debated and negotiated, it shows how the classification of geological time became a GSSP-based institutional practice through specific procedures, standards, and conventions for recognizing particular stratigraphic signals as valid evidence for defining geological time. Against this historical backdrop, the second part points out that, from its inception, the Anthropocene has carried the reflexive mode of thinking about the consequences of human activities, such as climate change, biodiversity loss, and habitability, hence calling for planetary stewardship. Since a new geological epoch can only be ratified through the acceptance of a specific GSSP proposal, formalizing the Anthropocene became a site at which the scientific norms constructed in the late 20^th century for the development of GSSP are brought into contact with the 21^st-century societal norms embedded in the concept of a human-driven Earth-system change. In a nutshell, the very term “Anthropocene” connotes both descriptive and prescriptive practices.

In 2023, the Anthropocene Working Group (AWG) submitted a GSSP proposal identifying plutonium-239 fallout from the mid-20^th-century nuclear testing as a globally synchronous marker, supported by multiple auxiliary stratigraphic proxies. As maintained by Skelton and Noone (2025) and the members of the AWG, this proposal has met the formal GSSP requirements with evidential robustness exceeding those of many previously ratified epochs. Nevertheless, the Subcommission on Quaternary Stratigraphy (SQS) voted to reject the proposal. This paper argues that the difficulties surrounding the formalization of the Anthropocene do not stem from matters of empirical evidence, but from matters of normative science: i.e., how existing scientific norms are to be interpreted, negotiated, and sometimes reconstructed when they encounter the pressure of societal imperatives to address planetary transformations. The paper thus asks how scientists should navigate the deeply humanistic implications of their stratigraphic decision about the Anthropocene.