In a vote, scientists deny that we are in the Anthropocene – 03/05/2024 – Environment

The Triassic was the dawn of the dinosaurs. The Paleogene saw the emergence of mammals. The Pleistocene included the last ice ages.

Is it time to mark humanity’s transformation on the planet with its own chapter in Earth’s history, the “Anthropocene”, or the human epoch?

Not yet, scientists decided, after a debate that lasted almost 15 years. Or a blink of an eye, depending on the angle from which you look.

A committee of about two dozen scholars voted overwhelmingly against a proposal to declare the beginning of the Anthropocene, a newly created epoch of geological time, according to an internal announcement of the vote results seen by The New York Times .

By geologists’ current timeline of Earth’s 4.6 billion-year history, our world is now in the Holocene, which began 11,700 years ago with the most recent retreat of the great glaciers.

Changing the chronology to say that we have advanced into the Anthropocene would represent a recognition that recent human-induced changes in geological conditions have been profound enough to end the Holocene.

The declaration would shape terminology in textbooks, research articles, and museums around the world. It would guide scientists in their understanding of our still-developing present for generations, perhaps even millennia.

Ultimately, though, the committee members voting on the Anthropocene in recent weeks weren’t just considering how defining this period had been for the planet. They also had to consider when, precisely, it began.

By the definition that a previous panel of experts spent nearly a decade and a half debating and crafting, the Anthropocene began in the mid-20th century, when nuclear bomb tests spread radioactive material throughout our world.

For several members of the scientific committee who evaluated the panel’s proposal in recent weeks, this definition was too limited, too recent and inadequate to be an adequate framework for reshaping the Homo sapiens on planet Earth.

“It restricts, confines, narrows the entire importance of the Anthropocene,” said Jan A. Piotrowski, a committee member and a geologist at Aarhus University in Denmark. “What was happening during the beginning of agriculture? What about the Industrial Revolution? What about the colonization of the Americas, of Australia?”

“The human impact goes much deeper into geological time,” said another committee member, Mike Walker, an Earth scientist and professor emeritus at the University of Wales Trinity Saint David. “If we ignore this, we are ignoring the true impact humans have on our planet.”

Hours after the results of the vote within the committee were circulated this Tuesday (5) morning, some members said they were surprised by the margin of votes against the Anthropocene proposal compared to those in favor: 12 to 4, with 2 abstentions.

Even so, on Tuesday morning it was unclear whether the results represented a conclusive rejection or whether they could still be challenged or appealed. In an email to the Times, committee chairman Jan A. Zalasiewicz said there were “some procedural issues to consider” but declined to discuss them further.

Zalasiewicz, a geologist at the University of Leicester, expressed support for the canonization of the Anthropocene.

This question of how to situate our time in the narrative of Earth’s history has placed the world of geological timekeepers in an unfamiliar light.

The grandly named chapters of our planet’s history are governed by a group of scientists, the International Union of Geological Sciences. The organization uses rigorous criteria to decide when each chapter began and what characteristics defined it. The goal is to maintain common global standards to express the planet’s history.

Geoscientists do not deny that our era stands out within this long history. Radionuclides from nuclear tests. Plastics and industrial ash. Concrete and metal pollutants. Rapid global warming. Sharp increase in species extinctions. These and other products of modern civilization are leaving unmistakable traces in the mineral record, especially since the mid-20th century.

Still, to qualify for entry into the geological time scale, the Anthropocene would have to be defined in a very specific way, one that meets the needs of geologists and not necessarily the anthropologists, artists and others who are already using the term.

Therefore, several experts who expressed skepticism about the enshrinement of the Anthropocene emphasized that the vote against should not be interpreted as a referendum among scientists on the broad state of the Earth.

“This is a specific and technical subject for geologists, for the most part,” said one such skeptic, Erle C. Ellis, an environmental scientist at the University of Maryland. “This has nothing to do with the evidence that people are changing the planet,” Ellis said. “The evidence continues to grow.”

Francine MG McCarthy, a micropaleontologist at Brock University in St. Catharines, Ontario (Canada), takes the opposite view: she helped lead some of the research to support the ratification of the new epoch.

“We are in the Anthropocene, regardless of a line on the time scale,” McCarthy said. “And acting accordingly is our only way forward.”

The Anthropocene proposal began in 2009, when a working group was convened to investigate whether recent planetary changes deserved a place in the geological timeline.

After years of deliberation, the group, which came to include McCarthy, Ellis and about three dozen others, decided yes. The group also decided that the best starting date for the new period was around 1950.

The group then had to choose a physical location that most clearly showed a definitive break between the Holocene and the Anthropocene. They chose Crawford Lake in Ontario, Canada, where the deep waters preserved detailed records of geochemical changes in the bottom sediments.

Last fall, the working group sent its Anthropocene proposal to the first of three governing committees of the International Union of Geological Sciences — 601% of each committee must approve the proposal for it to advance to the next.

Members of the first committee, the Subcommittee on Quaternary Stratigraphy, submitted their votes beginning in early February. (Stratigraphy is the branch of geology dedicated to the study of layers of rock and how they relate to each other over time. The Quaternary is the ongoing geological period that began 2.6 million years ago.)

According to the rules of stratigraphy, every time interval on Earth needs a clear and objective starting point, which applies worldwide. The Anthropocene working group proposed the mid-20th century because this encompassed the postwar explosion of economic growth, globalization, urbanization, and energy use.

But several members of the subcommittee said that humanity’s transformation on Earth was a much broader story, one that may not even have a single start date across all parts of the planet.

For this reason, Walker, Piotrowski, and others prefer to describe the Anthropocene as an “event,” not an “epoch.” In the language of geology, events are a broader term. They do not appear on the official timeline, and no committee needs to approve their start dates.

However, many of the planet’s most significant events are called events, including mass extinctions, rapid expansions of biodiversity, and the filling of Earth’s skies with oxygen 2.1 billion to 2.4 billion years ago.

Even if the subcommittee’s vote is upheld and the Anthropocene proposal is rejected, the new epoch could still be added to the timeline at some later point. However, you will have to go through the entire discussion and voting process again.