Two years after the International Union of Geological Sciences (IUGS) voted to reject the proposal for a new geological epoch named the Anthropocene, a fresh controversy has emerged regarding the legitimacy of that decision. According to scholars, unpublished documents suggest the rejection was procedurally flawed and that the rationale provided was insufficiently explained.
Jürgen Renn, a historian of science at the Max Planck Institute of Geoanthropology in Jena, Germany, co-authored a paper published today in the journal Earth’s Future detailing these accusations. Renn emphasized the historic nature of the vote, stating, “It should be clear to the world — it should be transparent.” The authors are calling on the IUGS to release key documents related to the vote and to conduct an independent review of the process to preserve “public trust in our capacity to understand and respond to planetary transformation.”
Researchers involved in the original vote have defended the integrity of the proceedings. Adele Bertini, a geologist at the University of Florence and co-chair of the voting subcommittee, expressed willingness to subject the documents to scrutiny if it aids the legacy of the research behind the proposal. She also noted that she recently co-authored a technical explanation for the rejection in the journal Nature Reviews Earth & Environment.
The dispute represents the latest escalation in a long-standing debate among geologists about formally recognizing the Anthropocene in the stratigraphic record. Currently, Earth is classified as being in the Holocene epoch, which began approximately 11,700 years ago following the last glacial period. In 2009, the Anthropocene Working Group was established to gather evidence that human industrialization had initiated a distinct new epoch.
The proposal argued that the Anthropocene began in 1952, marked by a layer of plutonium from nuclear weapons testing found in Earth’s strata. This physical indicator coincided with other significant human-driven changes, such as rising concentrations of carbon dioxide and methane in the atmosphere. Jan Zalasiewicz, a geologist at the University of Leicester who led much of the working group’s efforts, maintained that the scientific case for the Anthropocene remains strong.
Zalasiewicz, who co-authored a review highlighting the evidence for the proposal, argued that a formal definition is necessary to provide stability and legitimacy to the term within the geosciences. However, when the proposal was put to a subcommittee of stratigraphers in 2024, it was rejected by a vote of 12 to 4, with two members abstaining.
Phil Gibbard, a geologist at the University of Cambridge who voted against the proposal, argued for a more flexible classification. He suggested referring to the Anthropocene as an “event” rather than an epoch, similar to the Great Oxidation Event, which marked a significant but not epoch-defining shift in Earth’s atmospheric composition.
I’m skeptical about the ‘flawed process’ claims. Geology has always been contentious, and votes like this are normal debate.
Does this political squabble matter to anyone outside academia? Climate change doesn’t care about our stratigraphic labels.
I find it surprising that procedural flaws are being alleged two years later. The science should speak for itself!
1952 seems like a solid marker, but calling it an ‘event’ rather than a full epoch might actually be more scientifically precise.
Transparency is crucial here. If the IUGS won’t release the documents, how can we trust their decision?