Despite official votes, the evidence of the Anthropocene is clear

Fierce academic infighting is nothing new, but this turmoil has important implications for our species. Geologic epochs define distinct periods in Earth’s history, defined by major changes in geological deposits, including fossils and geochemical signals. The move away from the Holocene, which represents relatively stable climatic conditions over the past 11,700 years, to the human-modified Anthropocene means that we have put Earth on a new trajectory, unlike any previous epoch, as geological and other scientific evidence undoubtedly indicates.

The debate over whether humanity had entered a new geological epoch began in 2000, when Nobel Prize-winning chemist Paul Crutzen interrupted a meeting of the International Geosphere-Biosphere Programme. Scientists were reporting new changes in the systems they studied. “Stop saying Holocene,” Crutzen grumbled. “We’re in the Anthropocene.” Crutzen was arguing that the criteria that define the Holocene had been violated by human activities.

Like beavers, prairie dogs, earthworms, and many other species, humans have been changing the Earth for thousands of years. For example, different approaches to agriculture have reshaped ecosystems. Around the mid-20th century^Number But something new happened in the 21st century: population, production and consumption of goods, and globalization began to grow. ExponentiallyHistorian John McNeill and chemist Will Steffen have dubbed this intensifying phase the “Great Acceleration.” Environmental geographer Ruth DeVries calls it the “Big Ratchet.”

Carefully and rigorously, Expert Panel The Anthropocene Working Group (AWG), a group of 33 scientists, has examined Crutzen’s claims. Over the course of 14 years, the AWG [of which Barnosky, this article’s coauthor, is a member] They reviewed hundreds of studies and conducted additional research of their own. Together with leading scientists from relevant fields, the AWG Decided Indeed, the parameters defining the Holocene have not only been substantially exceeded around the world but in some areas have been disrupted, pushing the Earth System past boundaries into a new normal.

The next question for geologists defining the geological era was when exactly did the change occur. Major periods in Earth’s history are marked by major shifts in geological strata. Periods can be determined in lake and ocean sediments, ice cores, peat bogs and coral reefs, all of which provide conclusive evidence that the Anthropocene is real.

Since about 1950 the geological record has changed. DramaticallyGeologists are finding new man-made minerals and rocks around the world, including radioactive fallout from nuclear bomb testing, many types of contaminants including “forever chemicals” and plastic particles, and large amounts of concrete. They are seeing rearrangements of terrestrial and marine sediments resulting from agriculture, cities, roads, dams, and water systems. Unique assemblages of plants and animals reflect the massive movement of species around the world and the replacement of wild animal bones with the remains of cattle, sheep, and other domestic animals. The records quietly assert that for the first time in Earth’s history, a single species became a geological force. Homo sapiens.

But for a new epoch to be officially designated, evidence for it must be synchronous across the globe — that is, it must appear in the geological record at the same time across the globe. This distinction is important: local developments do not necessarily lead to changes in the functioning of the entire Earth system; large, global changes do.

In 2023, 12 teams of scientists from around the world presented their findings. evidence To help pinpoint a single place that could exemplify the transition from the Holocene to the Anthropocene. From the Baltic Sea to Antarctica, from the San Francisco Bay area to the lakes of China, to the coral reefs of the Gulf of Mexico and the Indian Ocean, the markers were almost numbingly uniform. Lake Crawford in Canada, a silent witness to the sediments that accumulated there over millennia, shows this history so clearly that it was chosen by the AWG as the place to hold the “golden spike” of the Anthropocene. Like other places, the lake showed a persistent geological signal that was significantly strengthened in the 1950s.

In a recent vote, the gatekeepers of geological time ignored the evidence of hundreds of peer-reviewed studies and insisted that the Anthropocene is a relative term that cannot be pinpointed, precisely pinpointed, or measured in time and space.

This small minority of scientists who oppose the Anthropocene ignore one of the most central tenets of their discipline: relying on data, not faith or certainty. Assert Humans have been modifying the environment since at least the advent of agriculture, so that by the mid-20th century^Number They argue that events since the 20th century are not special enough to be designated as a geological period. They fail to acknowledge that early developments in human technology did not have simultaneous effects on a global scale, as evidenced by the mid-20th century.^Number While these advances were part of the preparation for the Anthropocene, they did not affect the entire planet at the same time and with rapidity. radically change The Earth’s operating system was developed in the mid-20th century.^Number The century did.

Some cultural critics opine that whether or not geologists officially define the Anthropocene, they will continue to recognize it. Artist,Writer, Historian, Sociologist, EpidemiologistSome, and others, do not rely on a formal designation to confirm that we are all living in an increasingly unstable environment. But international scientific consensus, based on a vast body of evidence and analysis, can guide us as we address the challenge. Failure to name the Anthropocene in a way that reflects the massive disruptions that began during the Great Acceleration and continue to this day will hinder efforts to support a safe operating space on Earth for humanity and the countless species on which we depend. The window of opportunity to take effective action to change our dangerous trajectory is rapidly closing.

In the past, there was fierce resistance to paradigm-shifting discoveries that changed basic ideas about Earth’s history. For example, the notion that plate tectonics continues to move the continents, or that a meteorite impact caused the mass extinction of the dinosaurs, were anathema to many people who held tightly to their inherited worldview. Eventually, the evidence was accepted by new generations, and these concepts made it into textbooks.

Ironically, Darwin might have been intrigued that the Anthropocene is in some sense a recovery of the biblical view of humanity’s place on earth. He might have marveled that a small, inconspicuous mammal could, through hundreds of millions of years of natural selection, acquire the power to transform the entire planet. Darwin might have conducted his own research into the Anthropocene, analyzing lake sediments. Looking at the evidence of a new epoch, his main questions might have been: “Can humans adapt to the changes they have brought about?” and “How much time do we have?”