Humanity is awaiting the declaration of a new geological era in the history of the planet
The announcement of the new era will mark a paradigm shift in scientific thinking - CC0
Humanity is preparing to record a new geological era in the history of the planet Earth , which depends mainly on the human impact on the planet, and scientists have chosen for it the name "The Anthropocene".
Since 2009, a group of geoscientists has been collecting evidence of humanity's transition to a new geological era resulting from human influence... And on Tuesday they will announce their latest findings, which is the starting point of the Anthropocene era, when the massive human impact on the planet began.
The expected announcement, Tuesday, during two scientific conferences in the French city of Lille and the German capital, Berlin, will culminate without firm conclusions, a scientific adventure launched in 2002 by Paul Crutzen, the Nobel Prize winner in chemistry thanks to his identification of the sources of the destruction of the ozone layer, and he is the first to talk about the emergence of this era that It has been described as the "era of human influence", in a theory that has not received official approval from the highest scientific authorities.
The Earth's 4.6 billion-year history is systematically divided into eras, periods, epochs, and geological eras, a division that students learn and develop from the International Commission on Stratigraphy. Humanity is currently living in the modern life period, the Quaternary era, the Holocene era (the modern era).
It was this committee that tasked the Anthropocene Working Group with de facto answering three key questions.
According to these questions, if a group of aliens during the next million years inspected the layers of rocks and sediments on Earth, would they discover a human impact important enough to conclude that a new geological frontier had been clearly crossed? If so, when do we find the clearest evidence of this? and where?
very difficult
As for the first question, the working group's answer is unequivocal, as they assert that humans did indeed take the planet out of the Holocene era, which began 11,700 years ago, after several ice cycles, and moved it to a "new world."
The effects of human activity, from microplastics to perpetual chemical pollutants, to invasive species and greenhouse gases, are everywhere, from mountain tops to ocean floors, and the disruptions they cause are many, including climate change, pollution, and biodiversity loss, to an extent. Breaking the natural balance of the globe.
For the team, the turning point is the mid-twentieth century, when all indications of human influence in sediments saw an explosive rise that scientists call the "Great Acceleration".
It remains to locate the symbolic place where this shift is most evident. It could be a lake, a coral reef, a glacier... Nine sites in China, Canada, Japan and elsewhere have been shortlisted for potential places in this context.
There is still great ambiguity surrounding this issue, especially in terms of knowing whether this work will be officially approved by the members of the International Committee for the Stratigraphy of the Earth, and then by the trustees of the International Union of Geosciences, which is known for its intransigence when it comes to amending the International Charter for the History of the Stratigraphy of the Earth.
The prevailing impression points to great difficulty in this regard. Some well-known geologists believe that the technical criteria required to characterize the Anthropocene as a new "epoch" have not been met, although they acknowledge that dramatic changes have occurred over the past century.
The "real" Anthropocene
So Phil Gibbard, the secretary of the International Commission on Stratigraphy, thinks the term "geological event" would be more appropriate.
In 2022, Gibbard stressed, "the conditions that caused the glaciations," a series of dozens of glacial cycles that occurred over the past million years, "have not changed, so we can expect the Holocene to be nothing more than an interglacial period."
But, according to proponents of classifying the Anthropocene as an ice age, for the first time in human history, not only has a species drastically altered Earth's morphology, chemical and biological composition, but this species realizes that it has done so.
Naming the era would push humanity to focus on future challenges, which Paul Crutzen called "a quantum leap in scientific thinking."
"We have to recognize that there are turning points," Johan Rockström, director of the Potsdam Institute for Research on the Effects of Climate Change, who is the author of a landmark study on planetary boundaries, told AFP.
For Jan Zalasiewicz, head of the working group, disapproval of the transition to the Anthropocene would leave the impression that the Holocene conditions that allowed human civilization to flourish still exist.
"It's clearly not," he told AFP, adding that "science is about distinguishing between what's real and what's not. The Anthropocene is real."
In terms of the impact of humans on the planet, researchers discovered in the depths of the Beppu Bay in Japan, a treasure in layers of sediment and mud, which is physical evidence that humanity has changed the planet.
Beppu is one of the candidate sites for the passage into the Anthropocene.
Michinobu Kowe, a professor at the Ehime Center for Marine Environmental Studies, has been studying the site for about a decade. His research initially focused on the impact of climate change on fish populations, with fish scales in sediment stocks providing clues.
It is only recently that the site has begun to be considered a hotspot for the study of the Anthropocene, given the "multiple anthropogenic signatures that include man-made chemicals and radionuclides found in the sedimentary layers of the bay."
"Human Impact on Earth"
To be considered significant, a site must provide evidence of at least a century of human origin, such as signs of nuclear testing, ecosystem change, and industrial development.
It should also provide complete archives for the period studied, information allowing scientists to identify each layer with the period during which it was formed.
The researchers consider coral reefs a good candidate because they grow in layers like tree trunks and absorb dissolved elements in the water, such as waste from nuclear tests.
But corals cannot capture elements that do not dissolve in water, such as microplastics.
Sediments from the Beibu Gulf contain fertilizers and elements from historical floods that are officially dated, as well as fish scales and plastic. Among the most striking data, according to Kawae and Yokoyama, are fingerprints from a series of nuclear tests conducted in the Pacific Ocean between 1946 and 1963.
The tests produced globally detectable atmospheric radiation, but also direct residues detected in places close to the test sites. "Both can be detected," Yokoyama commented.
Samples from the bay showed amounts of plutonium consistent with specific nuclear tests, and this matched similar results at the nearby Ishigaki coral reef.
Source : websites