Scientists have voted against a proposal to declare a new geological epoch called the Anthropocene to reflect how profoundly human activity has altered the planet.

The proposal was rejected by members of the , which is part of the International Union of Geological Sciences, according to three voting members of the subcommission contacted by CNN Tuesday.

The vote followed a 15-year process to select a geological site that best captures humanity鈥檚 impact on the planet. The international union鈥檚 Anthropocene Working Group, which spearheaded the effort, made a July 2023 announcement that because of the way sediment from the lake bed reveals the geochemical traces of nuclear bomb tests, specifically plutonium, from 1950.

The vote was not unanimous, said Kim Cohen, an assistant professor of geosciences at Utrecht University in the Netherlands and a voting member of the subcommission.
鈥淭here were some abstainees. There was a minority of yeses to a majority of nos,鈥 said Cohen, who voted in favor of the proposal.

Phil Gibbard, a professor emeritus of quaternary paleoenvironments at the Scott Polar Research Institute at the University of Cambridge in the United Kingdom, and a voting member of the subcommission, said that the 鈥減roposal for a formal Anthropocene was rejected by a 66 per cent vote.鈥

'Very disappointing'

The geologic time scale provides the official framework for our understanding of Earth鈥檚 4.5 billion-year history. Geologists break down our planet鈥檚 history into eons, eras, periods, epochs and ages 鈥 with an eon being the largest chunk of time and an age the shortest.

While few scientists doubt the impact humans have made on the planet, the geological community was divided about whether the changes rose to the level of epoch, suggesting it was too soon in geological terms for such a declaration.

Some experts argued that the start of the Anthropocene could be better defined in other ways, such as the beginning of the Industrial Revolution. Others have suggested the impact of humans on Earth was better classified as a geological event that unfolds gradually over a long period of time.

Colin Waters, the chair of the AWG who led the development of the proposal to make the Anthropocene an official part of Earth鈥檚 geological history, said the outcome of the vote was 鈥渧ery disappointing.鈥

鈥淲e have as a group many eminent researchers in their field of expertise who wish to carry on as a group, in an informal capacity, that will continue to argue the case that the evidence for the Anthropocene as an epoch should be formalised, as consistent with the scientific data presented in the submission,鈥 said Waters, an honorary professor at the School of Geography, Geology and the Environment at the University of Leicester, via email.

鈥淚f the above vote is confirmed鈥 then the current proposal cannot progress, but given the existing evidence, which continues to grow, I would not be surprised if there is a future call for a proposal to be reconsidered,鈥 he said.

The term 'Anthropocene' is in wide use

The proposal will not go any further at this stage, said David Harper, a professor emeritus of paleontology at Durham University and the chair of the International Committee of Stratigraphy, which would have held a vote on the proposal if the subcommission had passed it.

The committee is also part of the International Union of Geological Sciences, which represents more than 1 million geoscientists around the world.

鈥淭his is the commission鈥檚 expert group for this interval of geological time and we are bound by its decision. The current proposal will proceed no further according to our statutes,鈥 Harper said via email, adding that he hadn鈥檛 been officially informed of the decision and wouldn鈥檛 comment any further.

Cohen said there were several arguments both for and against the proposal raised during the six-week period of discussion by the subcommission, but declined to give further detail. Regardless of whether the term is officially classified as a geological epoch, Anthropocene is already widely in use, Cohen noted.

鈥淓verybody talks about it already. In journals, many people use it. But in geology, not so many as all the other sciences,鈥 he said.