Paris, France: Scientists are presenting compelling evidence that the Earth has transitioned into the Anthropocene epoch, characterized by significant human influence. The era, which began in the mid-20th century, is marked by soaring greenhouse gases, ubiquitous microplastics, pervasive “forever chemicals,” global disturbances in animal populations, and even the remnants of old mobile phones and chicken bones.
Jan Zalasiewicz, a British geologist who chaired the Anthropocene Working Group, was asked if there remained any place on Earth untouched by human impact. Reflecting for a moment, he expressed that it was difficult to think of a more remote location than the Pine Island glacier in Antarctica. However, when scientists conducted deep drilling beneath the glacier a few years ago, they discovered traces of plutonium. These remnants were remnants of radioactive fallout resulting from nuclear weapon tests that commenced in 1945, leaving an unprecedented radioactive signature.
Zalasiewicz stated that these radionuclides might represent the most distinct indicator marking the initiation of the Anthropocene epoch 70 years ago. Nevertheless, he acknowledged the abundant options available when identifying evidence of human influence.
On Tuesday, the Anthropocene Working Group is expected to reveal its selection for the epoch’s “golden spike” location—a site that best exemplifies the myriad ways in which humans have transformed the world. However, the announcement will not immediately establish the Anthropocene as an officially recognized geological time unit, as geologists worldwide continue to analyze the evidence.
The Anthropocene reveals numerous noteworthy aspects, and one particularly unsurprising element is the exponential surge of carbon dioxide and other greenhouse gases, which are recognized as primary contributors to global warming. Zalasiewicz explained that numerous changes occurred when humans acquired the ability to extract fossilized sunlight in the form of oil, coal, and gas from the ground. Anthropocene scientists have demonstrated that humans have consumed more energy since 1950 than the total energy consumption in the previous 11,700 years of the Holocene epoch.
This newfound power enabled humans to dominate the world in unprecedented ways. Land and animals were exploited to sustain the rapidly growing human population. A study in 2018 estimated that humans and their livestock account for 96 percent of the biomass of all land mammals on the planet, leaving only four percent for wild mammals. Furthermore, supermarket chickens, selectively bred to attain sizes far larger than their natural counterparts, comprise two-thirds of the biomass of all birds.
Human activities have also led to the global redistribution of species, introducing invasive organisms such as rats to even the most remote Pacific islands.
In 2020, researchers estimated that the combined mass of human-made objects surpassed the weight of all living organisms on Earth, dubbing these objects “technofossils.” Items like successive generations of mobile phones, which quickly become obsolete, are examples of technofossils that will endure as part of the Anthropocene record.
Microplastics, tiny plastic particles, have been detected in the highest mountain peaks and the deepest ocean trenches. Additionally, substances like PFAS or “forever chemicals,” used in products like non-stick cookware, are increasingly being found worldwide.
The list of potential markers for the Anthropocene includes pesticides, fertilizers, rising levels of nitrogen and phosphorus, and even buried human remains. The scientists suggest that these markers will be preserved for hundreds of thousands of years, providing future generations or any other curious beings with insights into this unique human era.
Considering the future, Mark Williams, a British paleontologist and member of the Anthropocene Working Group, expressed the hope for positive human responses as a defining signal of the Anthropocene. While the fossil record does not currently indicate a mass extinction event, Williams warned that it is a looming possibility.
“We have two paths ahead,” he added.
Regarding untouched regions, the scientists reached a consensus that the only remaining place potentially unaffected by human fingerprints is likely located beneath the ice in Antarctica. However, Zalasiewicz cautioned that if no changes occur, these ice sheets will steadily melt due to global warming, erasing the last vestiges of an untouched domain.
