The quest to declare the Anthropocene an official geological epoch has descended into an epic row, after the validity of a leaked vote that apparently killed the proposal was questioned.
Supporters of the idea have been working on the proposal for 15 years. They say it would formalise the undeniable and irreversible changes that human activity has wreaked on the planet. It would mark the end of the Holocene epoch, the 11,700 years of stable global environment in which the whole of human civilisation developed.
Opponents argue that pinpointing the start of the human age to a particular date fails to recognise the long history of anthropogenic changes, through farming for example.
The proposal set the start date of the Anthropocene in 1952, marked by the worldwide fallout of plutonium from nuclear weapons’ tests. A new epoch also requires a specific location to represent the change and the sediments collected in a sinkhole lake in Canada were selected in July.
However, a geological committee – the Subcommission on Quaternary Stratigraphy (SQS) – voting in February sank the proposal by 12 votes to four, according to a report by the New York Times. Subsequently, the chair of the SQS said the “alleged” vote was in “violation of the statutory rules” and requested an inquiry into the affair.
The chances of the Anthropocene being formally adopted appear slim, with the chair of the International Commission on Stratigraphy, which oversees the SQS having told Nature magazine that the proposal “cannot be progressed further”.
If the vote is confirmed, a new proposal could be submitted. Either way, the concept of the Anthropocene is already widely used to describe the planet-altering impact of humanity.
An alternative proposal could be to declare the Anthropocene a geological “event”. These take place over time, are not part of the official geological timescale and do not need committee approval. Mass extinctions and the oxygenation of the atmosphere 2bn years ago are called events.
“Human impact goes much deeper into geological time,” said Prof Mike Walker, SQS member and at the University of Wales, Trinity Saint David. “If we ignore that, we are ignoring the true impact, the real impact, that humans have on our planet.”
However, the SQS chair, Prof Jan Zalasiewicz, from the University of Leicester, said: “The alleged voting has been performed in contravention of ICS statutes. Violation of the statutory rules included those about the eligibility to vote and other vital rules for securing a due scientific process. The [leak] has exposed the SQS, and by default its parent scientific bodies, to a considerable potential for reputational damage.”
Zalasiewicz, supported by one of the SQS vice-chairs, said he had requested an inquiry “including instituting a procedure to annul the putative vote”.
Philip Gibbard, an SQS member from the University of Cambridge, told Nature that the crux of the annulment challenge was an objection to the voting process kicking off on 1 February, when the rest of the committee wanted to move forward: “There’s a lot of sour grapes going on here.”
Prof Colin Waters, chair of the Anthropocene Working Group that developed the proposal, told the Guardian: “Irrespective of the vote, the AWG stands fully behind its proposal, which demonstrated beyond reasonable doubt that the Earth system now clearly lies outside of the relatively stable interglacial conditions of the Holocene [and] that the changes are irreversible.“
Waters said: “Anthropocene strata are also distinct from Holocene strata. They can be characterised using more than 100 durable sedimentary signals including anthropogenic radionuclides, microplastics, fly ash and pesticide residues, most of which show sharp increases in the mid-20th century.
“The Anthropocene, though currently brief, is of sufficient scale and importance to be represented on the geological timescale,” he said. “We will continue to argue the case and I would not be surprised if there is a future call for a proposal to be reconsidered.”
