This word was rejected by geologists. But it’s already taken over the world.

Earlier this year, a panel of geologists rejected a proposal to officially designate the past seven decades, during which humans profoundly impacted the environment, as the new chapter in the planet’s history.

But as these scientists spent years debating, the term became widely adopted outside geology to encapsulate the angst around environmental degradation — popping up in book titles, music albums and art exhibitions.

For the term’s proponents, the idea that humanity has pushed the Earth into a new geological epoch should serve as a wake-up call. “It’s only been 70 years,” said Francine McCarthy, a professor of earth science at Brock University in Ontario, referring to the start of the new proposed epoch. “We don’t have another 70 years to wait.”

The name’s persistence speaks to a need for a cultural shorthand for referring to the big, complex ecological changes that are defining the present era, advocates say — something akin to terms like the Cold War or the Internet Age that came before it. Even if geologists say they cannot pinpoint its exact start, it is obvious to many who continue to use the term that the Anthropocene has begun.

“I always thought that this geological discussion was perhaps too soon,” said ecologist Inês Martins, whose employer — the Leverhulme Center for Anthropocene Biodiversity at the University of York — has embraced the term. “But the reality is it is a very useful concept to use to identify an era where humans have increased their impacts.”

The term burst into public consciousness in 2000, when the Nobel Prize-winning chemist Paul Crutzen suggested the global effect of human activities was so profound that Earth was no longer in the Holocene, the current geological epoch.

“I was at a conference where someone said something about the Holocene, the long period of relatively stable climate since the end of the last ice age,” Crutzen recalled years later to the author Fred Pearce. “I suddenly thought that this was wrong. The world has changed too much. So I said: ‘No, we are in the Anthropocene.’ I just made up the word on the spur of the moment. Everyone was shocked.”

The coinage is a combination of the prefix “anthropo-,” which comes from the Greek word for human, and suffix “-cene,” derived from the Greek for “new” or “recent.”

The five most recent epochs all deploy “-cene” but lack the specificity of Crutzen’s new name, according to Merriam-Webster, with names simply referring to how far in the past each is.

Crutzen, who died in 2021, knew a thing or two about humans degrading the atmosphere, having won his Nobel for his work explaining how pollution was stripping Earth’s protective ozone layer.

Earthbound geologists took his idea seriously. In 2009, a scientific body called the International Commission on Stratigraphy appointed a working group to search for a so-called “golden spike” for the new epoch — a literal place on Earth where the rock record shows a clear transition from one ancient time to the next. For example, the Jurassic period, famous for its dinosaurs, is named after the Jura Mountains in Europe.

Scientists have put forward plenty of possible start dates. Crutzen himself suggested the second half of the 18th century, as greenhouse gases accumulated in glacial ice. The official Anthropocene Working Group proposed a spike in plutonium found in the mud of Crawford Lake in Canada, the result of nuclear weapons testing in the 1950s.

McCarthy, who studies the lake and argues that a plutonium-laced layer of sediment built up on its bottom should serve as a new “golden spike,” said the fact that the Anthropocene began so recently should send a sobering message to society to act fast to slow climate change. “That’s the scary part, is how quickly we have come to this point.”

But in a contested vote in March, a subpanel of the International Commission on Stratigraphy, the group charged with dividing the planet’s history into units that correspond with the geologic record, rejected that proposal, with some members arguing that such a recent feature should not define an epoch. Under its rules, geologists cannot submit another Anthropocene proposal for at least 10 years.

“Sediment deposited within my lifetime is not a new epoch, by any standards,” said Philip Gibbard, a University of Cambridge geologist who voted against the official Anthropocene proposal.

‘The cat’s out of the bag’

Golden spike or no golden spike, the Anthropocene isn’t going anywhere.

In a statement after the vote, the International Commission on Stratigraphy acknowledged the term will “continue to be used not only by Earth and environmental scientists, but also by social scientists, politicians and economists, as well as by the public at large.”

“It will remain an invaluable descriptor of human impact on the Earth system,” the commission added.

Even the term’s critics admit it has staying power. “The term Anthropocene is unfortunately here to stay,” Gibbard said. “The cat’s out of the bag. The horse has bolted. We can’t stop it.”

If anything, all the headlines on the rejection have only heightened the public’s awareness of the term. “It is definitely drawing more attention” to it, said McCarthy. “Even those people who are against — the no vote people — most of them would probably agree that we are in the Anthropocene,” she added.

The term is being searched for online about as much in the months since the March decision as it was during the months prior, according to Google Trends, and is still popping up in scientific studies, including in the prestigious journal Nature.

“It’s a good term that explains what we do to the planet,” said climatologist Jan Esper, who wrote a recent Nature paper that found that the summer of 2023 was the hottest in the Northern Hemisphere in 2,000 years.

The evolution of the concept is still underway. Norman Wirzba, a professor of theology at Duke Divinity School, said the name Anthropocene may imply that all of humanity is responsible for climate change, even though a handful of countries are responsible for the majority of greenhouse gas emissions.

“The question is, why are we calling this the Anthropocene when it’s very clear that what really made this happen was capitalism?” said Wirzba, who noted an alternative name for the current epoch: the “Capitalocene.”

“To lump all of humanity together,” he added, “is not discriminating enough.”

Gibbard, the geologist, has another idea. He wishes for the Anthropocene to be regarded as an ongoing “event,” a term used in geology to describe ancient episodes that leave a mark in the rocks.

Geological events can be something as simple as a footprint left in the mud or as cataclysmic as a volcanic eruption and the dinosaur-killing asteroid that led to mass extinction. For science to work, Gibbard said, researchers need to agree on what words mean.

“It would be most unsatisfactory if we had a term that could not be used, or is being used, in different ways in different disciplines,” he said. But he added that no geologist is in a position to stop people from using words how they wish. “We are not policemen. It is not our job to police the language.”

But for others, the term’s vagueness is exactly what gives it strength.

“We all as a community of citizens of planet Earth decided that this was a word to refer to the age of humanity, and the flexibility that different groups brought to that term really gave it a lot of power,” said Jacquelyn Gill, a paleoecologist at the University of Maine. “The fact that the Anthropocene has eluded definition is a feature and not a bug.”

“Geologists and stratigraphers don’t own the concept,” she added. “People can just walk outside, and they recognize we’re in the Anthropocene.”