The New York Times
The Triassic period was the birth of the dinosaurs. Mammals emerged in the Paleogene. 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 human epoch?
Not yet, scientists decided after an almost 15year debate. Or a blink of an eye, depending on which angle you look from.
According to an internal New York Times notice of the voting results, a committee of about two dozen scientists voted overwhelmingly against a proposal to declare the beginning of the Anthropocene, a newly created epoch of geological time.
According to geologists' current timeline of Earth's 4.6 billion years of history, our world is now in the Holocene, which began 11,700 years ago with the recent retreat of major glaciers.
Changing the chronology so that we have advanced into the Anthropocene would be an acknowledgment that recent humaninduced changes in geological conditions were profound enough to end the Holocene.
The declaration would shape terminology in textbooks, research articles and museums around the world. It would guide scientists for generations, perhaps even millennia, in their understanding of our stillevolving present.
Ultimately, the committee members who voted on the Anthropocene in recent weeks were not just concerned with how formative this period has been for the planet. They also had to consider when exactly it started.
According to the definition that an earlier panel of experts debated and elaborated for nearly a decade and a half, the Anthropocene began in the mid20th century, when atomic bomb testing spread radioactive material throughout our world.
For several members of the scientific committee who have evaluated the panel's proposal in recent weeks, this definition was too limited, too current and inadequate to provide an adequate framework for the transformation of Homo sapiens on planet Earth.
“It limits, limits and narrows the entire meaning of the Anthropocene,” said Jan A. Piotrowski, a committee member and geologist at Aarhus University in Denmark. “What happened at the beginning of agriculture? What about the Industrial Revolution? What about the colonization of America and Australia?”
“Human influence extends much deeper into geologic time,” said another committee member, Mike Walker, a geoscientist and professor emeritus at the University of Wales Trinity Saint David. “If we ignore this, we ignore the true impact that humans have on our planet.”
Hours after the results of the vote within the committee were distributed this Tuesday morning (5), some members said they were surprised at the margin of votes against the Anthropocene proposal compared to those in favor: 12 to 4, with 2 abstentions.
Still, it was unclear Tuesday morning whether the results represented a final 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 our time should be classified in the narrative of earth's history has cast the world of geological timepieces in an unusual light.
The magnificently named chapters of our planet's history are led by a group of scientists called the International Union of Geological Sciences. The organization uses strict criteria to decide when each chapter began and what characteristics defined it. The aim is to maintain common global standards for representing the history of the planet.
Geoscientists do not deny that our time stands out in this long history. Radionuclides from nuclear tests. Plastics and industrial ash. Pollutants from concrete and metal. Rapid global warming. Sharp increase in species extinction. These and other products of modern civilization have left unmistakable traces in the mineral stock, especially since the middle of the 20th century.
However, to be included on the geologic time scale, the Anthropocene would have to be defined in a very specific way that meets the needs of geologists and not necessarily the needs of the anthropologists, artists, and others who already use the term.
Several experts who expressed skepticism about the entrenchment of the Anthropocene therefore emphasized that the no vote should not be interpreted as a referendum among scientists on the general state of the Earth.
“This is largely a specific and technical issue for geologists,” said one of those skeptics, Erle C. Ellis, an environmental scientist at the University of Maryland. “This has nothing to do with the evidence that humans are changing the planet,” Ellis said. “The evidence continues to mount.”
Francine MG McCarthy, a micropaleontologist at Brock University in St. Catharines, Ontario, Canada, takes the opposite view: She helped lead some research in support of the ratification of the new era.
“We are in the Anthropocene, regardless of any 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 study whether recent planetary changes deserve a place in the geologic timeline.
After years of deliberation, the group, which included McCarthy, Ellis and about three dozen others, decided “yes.” The group also decided that the best start date for the new period was around 1950.
The group then had to select a physical location that most clearly revealed the final break between the Holocene and Anthropocene. They chose Lake Crawford in Ontario, Canada, where the deep water preserved detailed records of geochemical changes in the bottom sediments.
Last fall, the working group sent its Anthropocene proposal to the first of three steering committees of the International Union of Geological Sciences — 60% of each committee must approve the proposal for it to advance to the next.
Members of the first committee, the Subcommittee on Quaternary Stratigraphy, cast their votes beginning in early February. (Stratigraphy is the branch of geology that deals with the study of rock layers and their relationship to one another 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 that applies worldwide. The Anthropocene Working Group suggested the mid20th century because it encompassed the postwar explosion in economic growth, globalization, urbanization, and energy consumption.
But several members of the subcommittee said that humanity's transformation on Earth is a much broader story that may not even have a single start date for all parts of the planet.
For this reason, Walker, Piotrowski, and others prefer to describe the Anthropocene as an “event” rather than an “epoch.” In the language of geology, events are a broader term. They do not appear on the official schedule and no committee is required to approve their start dates.
However, many of the planet's most significant events are called events, including mass extinctions, the rapid expansion of biodiversity, and the filling of Earth's sky with oxygen between 2.1 and 2.4 billion years ago.
Even if the subcommittee's vote is affirmed and the Anthropocene proposal is rejected, the new epoch could still be added to the timeline at a later date. However, you have to go through the entire discussion and voting process again.