Scientists say the Anthropocene began in the 1950s: NPR

Trees surround Crawford Lake in Milton, Ontario, Monday, July 10, 2023. A new geological epoch defined by how humans impact the Earth should be marked by a team of scientists at pristine Crawford Lake outside of Toronto in Canada.

Cole Burston/The Canadian Press via AP

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Cole Burston/The Canadian Press via AP

Trees surround Crawford Lake in Milton, Ontario, Monday, July 10, 2023. A new geological epoch defined by how humans impact the Earth should be marked by a team of scientists at pristine Crawford Lake outside of Toronto in Canada.

Cole Burston/The Canadian Press via AP

From climate change to species loss and pollution, humans have etched their impact on the Earth so strong and lasting since the mid-20th century that a special team of scientists says a new geological era began in that time.

This era, dubbed the Anthropocene—derived from the Greek terms for “man” and “new”—began sometime between 1950 and 1954, according to the scientists. While there is evidence around the world that captures the impact of burning fossil fuels, detonating nuclear weapons, and dumping fertilizer and plastic on the ground and into waterways, scientists are proposing a small but deep lake outside of Toronto, Canada — Lake Crawford — to create a historic marker.

“It is quite clear that the scale of change has intensified incredibly and this must be a human influence,” said University of Leicester geoscientist Colin Waters, who chaired the Anthropocene working group.

This puts the power of humans into a somewhat similar category with the meteorite that slammed into Earth 66 million years ago, killing the dinosaurs and ushering in the Cenozoic Era, or what is known as the Age of Mammals. But not quite. While this meteorite started an entirely new era, the working group suggests that humans only started a new era, a much smaller geological time period.

The group aims to determine an exact start date for the Anthropocene by measuring plutonium levels at the bottom of Lake Crawford.

The idea of ​​the Anthropocene was proposed at a scientific conference more than 20 years ago by the late Nobel Prize-winning chemist Paul Crutzen. Teams of scholars have debated the issue ever since, eventually forming a working group to study whether it was needed and, if so, when the epoch would begin and where it would be celebrated.

Lake Crawford, which is 79 feet (29 m) deep and 25,800 square feet (24,000 m2) wide, was chosen over 11 other sites because the annual impacts of human activity on Earth’s soils, atmosphere, and biology are clearly preserved in sediment layers. This includes everything from nuclear fallout to species-threatening pollution to steadily rising temperatures.

Francine McCarthy, a member of the specialized committee on this site as a professor of earth sciences at Brock University in Canada, said that there are distinct and multiple signals that began around 1950 in Lake Crawford showing that “human influences overwhelm the Earth system.”

“The remarkably well-preserved annual record of sedimentation at Lake Crawford is truly astonishing,” said Marcia McNutt, president of the US National Academies of Sciences, who was not part of the panel.

Many scientists have said that the Anthropocene shows the power – and arrogance – of humanity.

“The arrogance of imagining we are in control,” said former White House science adviser John Holdren, who was not part of the working group for scientists and does not agree with the proposed start date, wanting a date much sooner. “The truth is that our ability to change the environment has far exceeded our understanding of consequences and our ability to change course.”

Geologists measure time in eons, eras, periods, epochs, and ages. The Scientific Working Group suggests that the Anthropocene followed the Holocene, which began about 11,700 years ago at the end of the Pleistocene.

They also suggest that he start a new era, naming it Crawfordan after choosing the lake as its starting point.

The proposal still needs approval by three different groups of geologists and could be signed off at a major conference next year.

The reason geologists have not declared the Anthropocene the beginning of a larger and more important time scale, such as the period, is because the current Quaternary epoch, which began roughly 2.6 million years ago, is based on permafrost at the Earth’s poles, which is still present. Waters said that in a few hundred years, if climate change persists and those people disappear, it may be time to change that.

“If you know your Greek tragedies, you know that power, arrogance, and tragedy go hand in hand,” said Naomi Oreskes, a historian of science at Harvard University who is a member of the working group. “If we do not address the harmful aspects of human activities, which are clearly disruptive to climate change, we are heading towards a tragedy.”