By Deborah Barsky, a writing fellow for the Human Bridges project of the Independent Media Institute, a researcher at the Catalan Institute of Human Paleoecology and Social Evolution, and an associate professor at the Rovira i Virgili University in Tarragona, Spain, with the Open University of Catalonia (UOC). She is the author of Human Prehistory: Exploring the Past to Understand the Future. Cross posted from Wiki Observatory.
Source: US Geological Survey
The evolution of the human mind has allowed us to transcend our modern understandings of time and expand into the realm of “deep time thinking.” One example of this is the Geologic Time Scale (GTS), a human construct that traces the astrophysical events that have affected the composition and structure of the Earth since it was formed some 4.6 billion years ago.
Scientists have assembled bits and pieces of this huge temporal scale into periods of relative climatic and biotic stability based on geological and fossil data. By ordering these events sequentially in time, they have been able to reconstruct when, how, and under what conditions life emerged on the planet. Under the aegis of the International Union of Geological Sciences (IUGS), the International Commission on Stratigraphy (ICS) is charged with defining geological epochs based on fundamental changes registered in the Earth’s geological formations. The GTS is often depicted with spiraling concentric branches divided into segments representing distinct geological epochs defined by periods of relative geobiological stability.
These epochs are named, dated, and ordered, and the length of each segment is proportional to its duration relative to the other phases. As we progress toward the outer rings of the spiral, we notice that the time segments gradually become smaller, especially around 500 million years ago after the unprecedented proliferation of complex life forms that appeared during the Cambrian explosion, which accelerated the pace of global ecological changes registered in the Earth’s layers.
The emergence of the first humanoid species has been traced back to only around 7 million years ago and is placed at the extreme tip of the last branch of the spiral, underscoring how little time has passed, relatively, since our ancestors appeared on the planet. Based on global climatic data, the evolutionary story of the genus Homo has taken place throughout the Quaternary Period that began around 2.58 million years ago during the Pleistocene Epoch. This period roughly overlaps with the invention of the first breakthrough human technologies made from stone. A global warming event that began 11,650 years ago around the same time as the emergence of early sedentary civilizations in the Fertile Crescent signals the start of the Holocene Epoch, in which we currently live.
The Anthropocene (The Age of Humans) has been proposed as a new geological epoch after or within the Holocene, and, if formalized, would be the first to be introduced based on geologically observable effects of human activity on the planet. This compelling proposal spurred the establishment of the Anthropocene Working Group (AWG), which is tasked to evaluate whether the geophysical signature of human behavior is sufficient to justify placing this new epoch at the apex of the spiraling branches of the GTS. While many scientists agree on the idea in principle, a major point of contention is when exactly the Anthropocene began.
Not surprisingly, pinpointing a precise threshold when human activity caused recognizable global geological alteration has proven to be a very difficult task that geologists and archeologists are working together to resolve. Some archeologists consider the Anthropocene as an incremental process, whose genesis can be identified diachronically in the Earth’s strata as early as tens of thousands of years ago, when modern humans consolidated planetary dominance, appropriating and transforming landscapes and biotic resources in archeologically detectable ways.
Anthropogenic signals, such as changes in ecosystems brought on by human overhunting of ice age megafauna, can be traced back to this period. By 10,000 years ago, plant and animal domestication boosted human ecosystem engineering as populations grew steadily through time. By around 5,000 years ago, the first urban dwellings drew swelling numbers of individuals into restricted areas, and technological innovation surged after the invention of metallurgy. Growing populations and intensified farming consumed and modified land, and animal husbandry led to increases in methane emissions traceable in the Earth’s sedimentary record.
The human imprint on the planet becomes significantly more conspicuous after the industrial age was launched in the Western world around 200 years ago, with an upsurge in carbon emissions from burning coal to feed technological development and increasing concentration of greenhouse gases driving global warming.
While viable arguments support each of these signposts along our evolutionary highway, the AWG concluded that the most suitable time to begin the Anthropocene would be in the 1950s, when the Great Acceleration sharply augmented the signs of human activity in the global geological record. This made the signs even more clearly distinguishable thanks to a wide range of indicators synchronously chronicling their symptoms, like climate deregulation, atmospheric, terrestrial, and water pollution, loss of biodiversity, excessive resource consumption, and massive land transformations.
In March 2024, the IUGS decided not to formally integrate the Anthropocene into the GTS; a verdict that has hardly quelled disagreements surrounding this matter. And there are other problems related to this issue. For example, while the existing chronostratigraphic divisions of the GTS register periods of stability lasting millions of years, the Anthropocene would be the first geological epoch to occur within only a human lifetime.
Even if we situate its beginning thousands of years before the industrial revolution, the Anthropocene sedimentary archive is currently still under formation. No matter the outcome of this fascinating planet-wide debate, the Anthropocene has indelibly entered into scientific and social discourse as the world faces many challenges posed by the unprecedented expansion of advanced human populations with unique techno-social behaviors that are now clearly linked to cataclysmic climatic events and biological genocide. It has become evident that the implications of the Anthropocene now exceed the question of its validity as a geochronological division in the Earth’s evolutionary history.
While geologists examine the end results of long-term paleoecological scenarios, archeologists center on more recent layers that record the origins and evolution of human life (the archeosphere). Fascinating interpretations are coming out of the collaboration between geologists and archeologists on the issue of the Anthropocene. Among these, the concept of the physical technosphere is particularly interesting since it addresses questions about how the entire mass of materials manufactured and modified by humans is becoming assimilated into the Earth system. In 2016, Jan Zalasiewicz and colleagues estimated the total mass of the physical technosphere to be a staggering 30 trillion tons, and it continues to grow, far surpassing both the volume and the diversity of the domesticated biosphere (plants and animals).
“We define the physical technosphere as consisting of technological materials within which a human component can be distinguished, with part in active use and part being a material residue. The human signature may be recognized by characteristics including form, function and composition that result from deliberate design, manufacture and processing. This includes extraction, processing and refining raw geological materials into novel forms and combinations of elements, compounds and products,” stated the article by Zalasiewicz and colleagues published in the Anthropocene Review, United Kingdom.
The study further added, “The active technosphere is made up of buildings, roads, energy supply structures, all tools, machines, and consumer goods that are currently in use or usable, together with farmlands and managed forests on land, the trawler scours and other excavations of the seafloor in the oceans, and so on. It is highly diverse in structure, with novel inanimate components including new minerals and materials… and a living part that includes crop plants and domesticated animals. Humans both produce and are sustained by (and now are dependent on) the rest of the physical technosphere.”
Although it was formed culturally because of anthropogenic agency, the technosphere combined with natural forces, has become an integral part of the functioning Earth system. It operates above and below the ground, in the seas, and even in outer space, with components interacting constantly and dynamically with the lithosphere, the biosphere, the hydrosphere, and the atmosphere.
While these other spheres have evolved over millions, or even billions of years, the technosphere—like the Anthropocene—has existed for a comparatively minute period of time. Continuously growing in pace with human demography and technological advances, the technosphere now generates so much excess waste that it cannot all be recycled back into the system, creating an imbalance in the structural relationships guiding the planet’s equilibrium and generating traceable Anthropocene deposits.
Beyond its physical aspects, the technosphere also encompasses the human social structures that enable it to function and in which all individuals play a part. Much like the synapses within the human brain or molecular systems forming the parts of a larger whole, humans constitute the individual components of the technosphere, cooperating to enable it to function while also creating the need for its existence.
“The technosphere is also manifest in the wide distribution of myriad artefacts such as needles, motors, and medicines, and by technological or technologically assisted processes like pumping and harvesting, as well as by nominally human activities that are closely tied to technological processes, such as watching television or filling out tax forms. Most such localized systems, processes and artefacts derive from, or are connected either directly or indirectly to, the globe-spanning networks of the technosphere,” stated the 2014 article by P. K. Haff, published in the Geological Society, London.
Following geological precepts and using methodologies classically applied in archeological sciences, the imprint of human activity on the planet is gradually being defined, quantified, mapped, and categorized, while novel subjects like technospheric taxonomy are being developed to complement traditional geological and stratigraphic practices. Just like the remnants of prehistoric material culture—like stone tools or pottery sherds—the objects we produce, use, and throw away in our daily lives are transforming into technofossils that will become markers in the chronocultural framework of human evolution, providing fodder for future archeologists.
At the generational scale, residues from polluting gases, sewage, toxic chemicals, and microplastics are melding into sedimentary layers, and artificial ground transformed by landfills, war rubble, mining, and urban settings is converted into novel anthropic geological settings with the passage of time.
There is no doubt that scarring and modification of land and sea resulting from wars, agriculture, urbanization, mining, and other human activities are being incorporated into the Earth’s geological layers. The evolution of human technologies has led our species to embark on an ongoing process that began incrementally and snowballed exponentially over the millennia, converting into the emblem of modern human heritage.
The global distribution of all human waste will be chronicled in relation to its position in sub-actual sedimentary formations that—in the not so distant future—will serve to define and classify the sequential cultural contexts of the Anthropocene.
20 comments
Comments are closed.
I followed the “Great Acceleration” link and found some very striking data comparing 1950 to 2021:
And still we must grow?
CO2, A daily CO₂ concentration of 431.25 ppm was recorded on May 10, 2025, at Mauna Loa, Hawaii, the highest daily average on record., Sam Carana, Arctic News.
Twenty more points in four short years, yet grow we must. Yikes.
Anthronecrotrophocine
Lol, produced and brought to market by Pfizer. The last pill you will ever have to take.
The “global warming period” that started 11,650 years ago is traceable to the Younger Dryas Events. A related claim that the extinction of the megafauna at about the same time as the Younger Dryas Event is due to human overhunting of said megafauna is not “written in stone” for several reasons. The Anthropocene can be titled that due to the primary expansion of Terran human populations across the globe, not necessarily to the primacy of the Terran human effect upon the globe. Yes, Terran humans do build cities, pollute the biosphere and do other measurable things to the globe, but they are also not capable of starting, stopping, nor modifying in a significant fashion natural forces such as earthquakes, volcanos, and extra-terrestrial sourced strikes, envelopments, plasma shroudings etc. etc.
As for global warming, all I can suggest is that the Earth will continue on, just not necessarily with a functional Terrestrial human technological civilization on it.
Finally, the contention that anthropocenic geologic features will follow us into the eternal future sound a lot like technologic hubris. The Earth is estimated to be 4.6 billion years old. Not all of that is even available for sampling; much of the very early strata have been subducted into the mantle and remelted and reformed as proto-historic substrate, geologically speaking. The proposed Anthropocine is barely twelve thousand years old. That works out to roughly .0000026 percent of the total age of the Earth.
Above is an example of the folly of the claim that “Man is the measure of all things.”
Man does measure, but does he really count?
Stay safe. Do the best with what you have.
Man is not going to have to count that high as this is the Tiny Tim of geological eras.
No time for semantics here as I’ve (three) cats to serve ; )
The experience of humans getting into virgin territory (Australia, Madagascar, New Zeeland) that did not happen 12,000 years ago but either much earlier or later, indicate that they do kill and eat the megafauna.
Yes, humans do overhunt, but the mass extinction of almost all megafauna in the Younger Dryas, particularly in North America, suggests that it was more than just that.
I follow the scenario proposed by the Younger Dryas Impact Theory, to which I find that the sudden extinction of the megafauna and the infamous “Black Mat” are the best arguments so far.
Black mat: https://pmc.ncbi.nlm.nih.gov/articles/PMC2373324/
Stay safe. Prepare for the worst and you’ll not be disappointed.
Humans migrated into North America earlier than the Younger Dryas event and did not eradicate the megafauna during all of that time. Finds at places like Monte Verde in Chile push Terran human habitation in the New World back to 19,000 years ago and probably earlier.
See: https://www.discovermagazine.com/planet-earth/monte-verde-our-earliest-evidence-of-humans-living-in-south-america
Genetic evidence places the peopling of the Australia New Guinea combined continent at 50,000 years ago. That’s a lot longer time with which to eradicate a smaller megafauna population than that which inhabited the North American continent.
The preponderance of the evidence says that whatever was responsible for the Younger Dryas events, there being probably two, separated by some 1200 years, did the bulk of the eradication of the megafauna of not only North America but Eurasia as well. As a side note, there is a long gap, over a thousand years, where there is a complete lack of Terran human artifacts in North America right after the Younger Dryas catastrophes.
In short, the old paradigms concerning the prehistory of Terran humans upon this globe are crumbling to dust in the face of new evidence that paints a quite different picture from that favoured by the “Official Narrative” of prehistory.
Stay safe.
Hey, wait a minute…I thought the Earth was only 7,000 year old?
I agree this smacks of hubris. Nature has a lot of recuperative power. For example, a few years ago I drove from Kaslo to Sandon B.C. along the right of way of the abandoned Kaslo and Slocan RR. At the turn of the last century this was the industrial frontier, with all the devastation to the environment that implies. Today, other than a few ruins, one would be hard pressed to find any trace of the mines, mills, and towns. The forest has reclaimed the area. I’m reminded of a statement by Gwynne Dyer in one of his videos back in the 90s (sorry, I can’t remember the title): “If we upset the balance of nature, nature won’t mind. It will just establish a new balance. WE however might have trouble adjusting to the new conditions.” We should perhaps wait a while before we start proclaiming that humans are the mark of a new geological era.
Or, in the words of a half-Anishinabe friend at the prospect of nuclear extinction (and counter to the “Gaia is suffering” theme):
It’ll be a bummer for us, but the earth won’t care.
I prefer defining the beginning of the Anthropocene coincident with the beginning of the nuclear age, which began shortly before the end of the Second World War. Large scale impacts of humankind on the Earth predate the Nuclear Age by tens of thousands of years, but I believe no other marker stands so characteristic of the impacts of humankind as the radioactive soil layer that begins the nuclear age. In any case, I believe this thin layer of soil contains decaying fission products that provide an easily detected, and exact time marker for later scientists to use – no matter where they mark the beginning of the Anthropocene. Also, I find sad irony in beginning the Anthropocene with the invention and first use of devices capable of achieving the complete end of the world and so near the impending collapse of the world we knew.
Though the world may “recover” from the presence of today’s Humankind, the climate will soon transition to a new epoch engineered by Humankind. This new climate epoch might serve as a memorial to the past presence of 20th and 21st century Humankind and its manifold excesses.
Gahan Wilson’s perspective:
https://www.newyorker.com/magazine/2009/10/26/3158183
Geologist here:
I’m firmly in the “no” camp. It’s an anthropological issue. Wait half a million years and then decide whether or not this is part of the Holocene, which in practice is rarely differentiated from the Pleistocene. They’re both generally lumped together by most geologists as it usually takes lab work to precisely identify the difference.
Interesting that the US Geological Survey graphic identifies the sub-periods Pennsylvanian and Mississipian rather than the Carboniferous period.
As for the Quaternary – well the Holocene/Pleistocene boundary isn’t so easy to differentiate here in Scotland where the physical impacts of the Loch Lomond re-advance are still being felt in isostatic readjustment.
My point is that most of geologic time, (excepting some catalclysmic extinctions) doesn’t have ultra sharp boundaries, and identifying the Younger Dryas as the commencement of the Anthropocene epoch is very much a debatable point.
I’d agree human induced changes are much more an anthropological issue, not being contemporaneous across the planet anyway.
You have a point about the uncertainty of just when Terran humans began to have measurable impacts upon the ecology and physical nature of the globe. However, the Younger Dryas events are such violent and consequential events upon both Terran human cultures and the physical world in which they lived that, all things being equal, using the Younger Dryas events as a convenient dividing line between the Pleistocine and the Anthropocine fits the available evidence.
the Earth chronicles Zecharia Sitchin.
Thank you for this article and the introduction to ‘Human Bridges’. I am familiar with ‘deep time thinking’. I have always considered it to be the Ultimate Extreme WOKE.
“The archeological record shows us, however, that even though human evolution appears to have taken place as a series of sequential stages advancing our species toward “progress,” in fact, there is no inherent hierarchy to these processes of development.
This takes a while to sink in, especially if you’ve been educated within a cultural framework that explains prehistory as a linear and codependent set of chronological milestones, whose successive stages may be understood by historically elaborated logical systems of cause and effect. It takes an intellectual leap to reject such hierarchical constructions of prehistory and to perceive the past as a diachronous system of nonsynchronous events closely tied to ecological and biological phenomena.”
https://observatory.wiki/How_Can_We_Understand_the_Passage_of_Time%3F