The term Anthropocene was first used in 2000 by atmospheric chemistry researcher and Nobel Prize winner Paul Crutzen during a conference. This evocative concept refers to the impact of the human species on the planet: our activity is causing changes in the climate, acidification in the oceans, increases in sea level, proliferation of invasive species, dispersal of new materials such as plastics and a long etcetera of transformations. These changes and impacts are of such magnitude that we could be talking about a new geological era in which human activity would be the main responsible for the climate and the environment on Earth.
Since Crutzen first spoke of the Anthropocene, the term has become popular and its use is common both in scientific conversations and in the media. However, at a formal level, defining a geological era is not that simple and, although the Anthropocene is often spoken of as such, technically we are in the Holocene era, within the Quaternary period.
The Anthropocene as it was geological
In order to determine if the Anthropocene is really a geological epoch and define its starting point, the International Commission on Stratigraphy formed in 2009 the Anthropocene Working Group (AWG), which in May 2019 , and after a decade of analysis of scientific evidence, published the results of an internal survey among the members of the committee. In this consultation, the experts voted on the convenience of considering the Anthropocene as a chrono-stratigraphic unit defined by a GSSP (Global Boundary Stratotype Section and Point) pattern, which defines the starting point of the period in question when a point is found. where some material has emerged that clearly indicates the change. This stratotype is marked with a golden nail.
With 29 votes in favor and 4 against, the AWG supports the designation of the Anthropocene as a new geological era beginning in the mid-20th century, at which time a rapidly growing human population accelerated the pace of industrial production, the use of agricultural chemicals and other activities with global repercussions. At the same time, the first atomic explosions covered the world with radioactive debris that embedded itself in sediments and glacial ice, becoming part of the geological record.
To make official the designation of the Anthropocene as a geological era there is still a long way to go, for example it is necessary to define the GSSP, that point that would mark the beginning of the new epoch. The group is considering ten candidate sites around the world, including a cave in northern Italy, locations on the Great Barrier Reef and a lake in China. According to the group’s experts, the most acute of the signals and that could be a primary marker would be the footprint of artificial radioisotopes that are scattered around the world due to nuclear tests carried out in the early 1950s.
Once a GSSP proposal is made, it must be accepted by a majority (more than 60% votes in favor) by the members of the AWG committee and its main bodies. In addition, the final ratification will be in charge of the Executive Committee of the International Union of Geological Sciences, so the success of the proposal is not guaranteed.
Other meanings of the term Anthropocene
In any case, the term Anthropocene, although it is not finally considered relevant on a geological scale, does not seem to disappear from our vocabulary, and there are many disciplines, beyond geology, that have found their usefulness in the scientific field. This is the case of the humanities and archeology, which use the concept of the Anthropocene to refer more broadly, for example, to the important changes in land use that have occurred since human activity intensified on the planet. .
Recently, a team of scientists from the University of Queensland (Australia), has published the results of a work in which they indicate that these changes and that the influence of man on the climate would have started long before the 20th century, specifically ago 4,000 years and coinciding, in a very logical way, with the beginning of agriculture.
” The activities of farmers, shepherds and hunter-gatherers would have significantly changed the planet four millennia ago, ” explained Andrea Kay, a scientist at the aforementioned University’s School of Social Sciences. His team has carried out a survey, framed within the ArchaeoGLOBE project, to collect estimates of land use in the last 10,000 years carried out by archaeologists from around the world.
The objective: to take into account the results of studies on a regional scale to analyze them from a global perspective. “Even changing small-scale agriculture can cause significant change when considered on a large scale and over long periods of time,” says Kay.
For Alison Crowther, another of the group’s researchers, the study could help plan future climate scenarios. “This research and the collaborative approach we use gives us a better understanding of land use as a driver of long-term global environmental changes throughout the system,” he says.
In any case, and whatever the beginning of the Anthropocene, what seems very clear is that our activity is responsible for many of the changes and processes that are taking place on the planet. It is up to us whether these changes take one direction or the other.
