Panel rejects a proposed geologic time division reflecting human influence, but the concept is here to stay
5 MAR 2024 – 4:00 PM ET
BY PAUL VOOSEN
For now, we’re still in the Holocene.
Science has confirmed that a panel of two dozen geologists has voted down a proposal to end the Holocene—our current span of geologic time, which began 11,700 years ago at the end of the last ice age—and inaugurate a new epoch, the Anthropocene. Starting in the 1950s, it would have marked a time when humanity’s influence on the planet became overwhelming. The vote, first reported by The New York Times, is a stunning—though not unexpected—rebuke for the proposal, which has been working its way through a formal approval process for more than a decade.
“The decision is definitive,” says Philip Gibbard, a geologist at the University of Cambridge who is on the panel and serves as secretary-general of the International Commission on Stratigraphy (ICS), the body that governs the geologic timescale. “There are no outstanding issues to be resolved. Case closed.”
The leaders of the Anthropocene Working Group (AWG), which developed the proposal for consideration by ICS’s Subcommission on Quaternary Stratigraphy, are not yet ready to admit defeat. They note that the online tally, in which 12 out of 18 subcommission members voted against the proposal, was leaked to the press without approval of the panel’s chair. “There remain several issues that need to be resolved about the validity of the vote and the circumstances surrounding it,” says Colin Waters, a geologist at the University of Leicester who chaired AWG.
Few opponents of the Anthropocene proposal doubted the enormous impact that human influence, including climate change, is having on the planet. But some felt the proposed marker of the epoch—some 10 centimeters of mud from Canada’s Crawford Lake that captures the global surge in fossil fuel burning, fertilizer use, and atomic bomb fallout that began in the 1950s—isn’t definitive enough.
Others questioned whether it’s even possible to affix one date to the start of humanity’s broad planetary influence: Why not the rise of agriculture? Why not the vast changes that followed European encroachment on the New World? “The Anthropocene epoch was never deep enough to understand human transformation of this planet,” says Erle Ellis, a geographer at the University of Maryland, Baltimore County who resigned last year in protest from AWG.
Opponents also felt AWG made too many announcements to the press over the years while being slow to submit a proposal to the subcommission. “The Anthropocene epoch was pushed through the media from the beginning—a publicity drive,” says Stanley Finney, a stratigrapher at California State University Long Beach and head of the International Union of Geological Sciences, which would have had final approval of the proposal.
Finney also complains that from the start, AWG was determined to secure an “epoch” categorization, and ignored or countered proposals for a less formal Anthropocene designation. If they had only made their formal proposal sooner, they could have avoided much lost time, Finney adds. “It would have been rejected 10 years earlier if they had not avoided presenting it to the stratigraphic community for careful consideration.”
The Anthropocene backers will now have to wait for a decade before their proposal can be considered again. ICS has long instituted this mandatory cooling-off period, given how furious debates can turn, for example, over the boundary between the Pliocene and Pleistocene, and whether the Quaternary—our current geologic period, a category above epochs—should exist at all.
Even if it is not formally recognized by geologists, the Anthropocene is here to stay. It is used in art exhibits, journal titles, and endless books. And Gibbard, Ellis, and others have advanced the view that it can remain an informal geologic term, calling it the “Anthropocene event.” Like the Great Oxygenation Event, in which cyanobacteria flushed the atmosphere with oxygen billions of years ago, the Anthropocene marks a huge transition, but one without an exact date. “Let us work together to ensure the creation of a far deeper and more inclusive Anthropocene event,” Ellis says.
Waters and his colleagues will continue to press that the Anthropocene is worthy of recognition in the geologic timescale, even if that advocacy has to continue in an informal capacity, he says. Although small in size, Anthropocene strata such as the 10 centimeters of lake mud are distinct and can be traced using more than 100 durable geochemical signals, he says. And there is no going back to where the planet was 100 years ago, he says. “The Earth system changes that mark the Anthropocene are collectively irreversible.”
doi: 10.1126/science.z3wcw7b
Uma (in)certa antropologia 