The recent International Union of Geological Sciences decision to reject the proposed “Anthropocene epoch” might seem confusing. Here’s a piece of draft material from my forthcoming book-in-progress, The New Lives of Images: Digital Ecologies and Anthropocene Imaginaries in More-than-Human Worlds, that attempts to bring the situation up to date. Comments welcome! Please note that the references to signs, signatures, and indexicality come from the book’s (processual-) semiotic approach to understanding images; if they seem abstruse, the first half of the book explains them clearly.
While it had some forerunners, the concept of the Anthropocene as a geological epoch was first proposed by atmospheric chemist Paul Crutzen and limnologist Eugene Stoermer in the year 2000. Within a few years, geologists were taking the concept as a serious proposal to mark a new epoch in the history of planet Earth, an epoch brought about by human activities.
For geologists, an epoch is not just any time period; it is part of a nested set of delineations: from smallest to largest and most encompassing, these are known as ages, epochs, periods, eras, and eons. Each is a geochronological unit, that is, a unit of time as marked by Earth history (geology) and determined through the practice of chronostratigraphy, or the reading and writing (-graphy) of layers of rock (strata) marking time (chronos). The entirety is based on the long verified observation that the remnants of the earth’s surface lay themselves down in horizontal layers, with the more recent laid on top of the less recent. The smaller chronostratographic units denote smaller levels of change over time; these combine to make up the larger ones, which denote larger changes.
The geologic time scale provides a kind of chronostratigraphic “address” for anything in the geologic record. We who live today are said to find ourselves “in” the Holocene or—if it should come to be accepted—the Anthropocene epoch, which are respectively the second and potentially third epochs of the third period (Quaternary) of the third era (Cenozoic) of the fourth eon (Phanerozoic) since the formation of the Earth. The Holocene, which began about 11,700 years ago, is roughly the thirty-eighth epoch in Earth’s history.
To say that we are in it, however, or in the Anthropocene, is to presume that we, or someone, could step out of time and see ourselves inside it. We cannot: we are at the leading edge (one of an infinity of leading edges) of a set of dynamic processes that unfolds not with the flatness of a unrolling roll of paper, but with noticeable folds, twists, and lumps. Whether today’s present will one day appear smooth or lumpy, or even form a dramatic twist in the geochronological fabric, cannot possibly be known until that present has become past. It will take additional layering on top of it—further epochs or ages at the very least—to see what it will look like once it is lain down. Geology is, after all (at least in its stratigraphic form), a reading of the past in the rockscape of the present.* Its ability to read the present is constrained by the fact that the present is not yet past. Its layering can only be predicted or, perhaps, divined.
Like other natural scientists, geologists work through the interpretation and production of indexical signs. (In short, an indexical sign is something that indicates a causal relationship to its referent, and not just a relationship of resemblance, which is an icon, or convention, which is a symbol.) Using physical instruments, they collect empirical observations of traces marking causal relationships. They measure, collate, and compare these to reveal causal trends and patterns in the world around us. They represent these graphically and interpret them in writing, which is published, distributed, read, discussed, debated, refined (or rejected), and projected into further research.
Empirical evidence, which is always evidence of something (and therefore of theory), in this way fuels theory-building, which gives rise to further evidence gathering, with representation and interpretation being a central part of the process. The indexical in this way becomes discursive, and vice versa. The work of science involves the production of what could be called “reversible indexicalities,” involving the building of what Bruno Latour calls a “reversible chain of transformations.” Within this chain, “indexicality is produced and sustained in circulation by scientists laboring to maintain the stability of indexical referents as they move from context to context.”[1]
The idea of a new epoch, and its proposed name, the Anthropocene, are discursive constructs—they are theoretical concepts developed to make sense of phenomena that can be measured empirically and assessed in reference to what is known. For those concepts to serve science, they must be able to operationalize indexical signs. And for the Anthropocene epoch proposal to become accepted by geologists, it must follow criteria developed by the geological community for identifying other epochs, including the signs and “signatures” that calls for.
The first such criterion, which led to the first challenge for proponents of the theory, was precise definition, including a precise starting point (since the epoch, if it is that, has only just begun).
Proposals for marking the beginning of the Anthropocene have ranged far and wide: they include the extinction of mammoths through human predation some 14,000 years ago; forest clearances and rice cultivation occurring 5 to 8 thousand years ago; the year 1610, as marking the Columbian Exchange, which resulted not only in the decimation of the majority of North and South America’s Indigenous societies, but a profound alteration of ecosystems including a noticeable dip in atmospheric CO2 concentrations; the onset of the industrial revolution, especially with the development of the steam engine; and the so-called Great Acceleration of the mid-twentieth century, with its introduction of radionuclides from hydrogen bomb tests alongside the deposits of plastics, concrete, and other technogenic substances across the world.
As with other steps in the process of identifying a geological epoch, the trajectory taken by the international geological community in articulating the Anthropocene has involved identifying clear and measurable demarcation criteria, reducing them to the clearest signal possible, and then identifying a site, a so-called “golden spike,” that reflects this signal especially well.
Selection and reduction has in effect occurred at multiple stages of the process. The geological community is as “nested” as its time scales, and within the International Union of Geological Sciences’ (IUGS, top level) International Commission on Stratigraphy (ICS, next level down), it is the Subcommission of Quaternary Stratigraphy (SQS, 3rd level, for our purposes) that has taken responsibility for the Anthropocene epoch proposal, which it has delegated to a group formed in 2009 called the Anthropocene Working Group (AWG, level 4).
In 2016, the AWG “decided by a majority vote that the Anthropocene possesses geological reality, that it is best considered at epoch/series level, that it is best defined beginning in the mid-twentieth century with the ‘Great Acceleration,’ and that it should be defined by a Global Stratotype Section and Point (GSSP).”[2] Between 2016 and 2022, the AWG developed criteria and evaluated evidence on behalf of a series of proposed sites around the world, of which one would be chosen as the “golden spike,” the single location that best records it in the geological record. In 2022, voting began on the site, and by 2023 the AWG had selected a small lake in Ontario, Canada, called Crawford Lake.
As Vox summarized it, in Crawford Lake “the waters are so deep that whatever sinks to the floor usually remains without mixing with the upper layers of water, so it stays preserved, offering an amazingly good record of geological change. Since the middle of the 20th century, the sediment there has been inundated by the byproducts of human activity: plutonium isotopes from the nuclear bombs we’ve detonated, ash from the fossil fuels we’ve burned, and nitrogen from the fertilizer we’ve used.”[3] The concept had thereby found its image, the ideal carrier of its indexicality, through a process of nomination, study, measurement, comparison, and evaluation.
Reading the notes and publications of the AWG, it is striking how often its members have been asked to vote on something or other, from the precise date of the beginning of the Anthropocene epoch and the candidate sites for the golden spike to much more refined details.[4] The entire process moved, in effect, from a global scale proposal—the Anthropocene as a marker of what makes the present different from the past—to a temporally specific date, which became November 1, 1952, coincident with the detonation of the first thermonuclear device, and finally to a specific site that best encompasses the criteria associated what the latter date. In the process of increasing the specificity of what was being identified, more and more of the richness of the original concept disappeared into the background.
This is what led long-time AWG member Erle Ellis to submit a public resignation letter in July 2023. In his letter, Ellis decried the “misleading and regressive perspective on Earth’s transformation by human societies” that he saw the AWG “now promoting.” Ellis wrote,
To define the Anthropocene as a shallow band of sediment in a single lake is an esoteric academic matter. But dividing Earth’s human transformation into two parts, pre- and post- 1950, does real damage by denying the deeper history and the ultimate causes of Earth’s unfolding social-environmental crisis. Are the planetary changes wrought by industrial and colonial nations before 1950 not significant enough to transform the planet? The political ramifications of such a misleading and scientifically inaccurate portrayal are clearly profound and regressive.
“The AWG’s choice,” he continued, “to systematically ignore overwhelming evidence of Earth’s long-term anthropogenic transformation is not just bad science, it’s bad for public understanding and action on global change.”[5] Calling it “bad science,” however, implicates the process for delineating other geological epochs and temporal units as well, all of which have followed more or less the same procedures, but with much lower political stakes.
Ellis’s complaints did not take place in a vacuum. By late 2023, the AWG had concluded its work and forwarded its proposal—for a “Crawfordian era” of an “Anthropocene epoch”—to the Subcommission on Quaternary Stratigraphy (the next level up). When, in March of 2024, the SQS voted against the proposal by a vote of 12 to 4 (with two formal abstentions and three other non-votes), AWG chair Colin Waters voiced his unhappiness. In a newsletter editorial, he complained of IUGS pressure to rush the vote, the ICS “breaching their own statutes and rules,” and the existence of a “catalogue of complaints about unethical behavior by those in high-office over the past decade who have aimed at preventing fair assessment of any proposal.”[6] The chair and vice-chair of the SQS committee responsible for the vote also claimed it was conducted illegitimately, with “procedural irregularities” including that several members were past their term limits. The chair, Jan Zalasiewicz, announced that he has been asked to step down from his role on the committee.[7]
The vote was nevertheless unanimously approved on March 20, 2024, by the IUGS executive (the highest level), which then announced that the Anthropocene epoch proposal was thus rejected.
The comments of some of those who voted against the proposal indicate that it was not necessarily a rejection of the Anthropocene idea, but that it was in part a rejection of its becoming an epoch. Some have proposed that it instead be considered an event, along the lines of mass extinctions or oxygenation of the Earth’s atmosphere, which may have catastrophic impacts but do not attain the temporal status of an epoch.
As it happens, then, the international geological community rejected the idea of an Anthropocene epoch at least in part because its own criteria had become too specific to reflect the concept’s original purposes. To put it in Latourian terms, the series of transformations failed to preserve the “reversible indexicalities” it called for. The motivation for delineating a new temporal unit had been to point to the overwhelming and multiple points of evidence that human activities had dramatically altered the planet’s surface. But by 2024, the process by which an epochal proposal gets vetted had reduced its own criteria to both a single start date and a single location on Earth to represent the change.
One might be forgiven for thinking that science was, in this respect, a victim of its own tendency to reduce its claims to the most indexically clear image, which in this case became a lake in Ontario. Science was also arguably “contaminated” here (I use the word without any judgment) by politics, that is, by some scientists’ quite understandable desire to have an effect in the world.
The result marks an important ambiguity in the very idea that geologists can speak of the present in the epochal terms by which they organize the past. To name the last 75 years the beginning of an “epoch” is to state that we have entered something definable and knowable. If instead the Anthropocene is the current name for an event or a condition that, in fact, defines the global situation today (as I’ve argued repeatedly on this blog and elsewhere), then it need not have geologists’ imprimatur at all.
Perhaps it is not the study of the past—through its indexical traces in the layers of the earth—but the study of the present that should be guiding our collective response to the global situation. The IUGS executive suggested as much in its statement announcing the decision: “Despite its rejection as a formal unit of the Geologic Time Scale,” they wrote, “the Anthropocene will nevertheless continue to be used not only by Earth and environmental scientists, but also by social scientists, politicians and economists, as well as by the public at large. It will remain an invaluable descriptor of human impact on the earth system.”[8]
What is, arguably, at stake between the framing of the Anthropocene as a new epoch into which we have entered and, alternatively, as an event and a condition to which we must respond, is the capacity to act. Framing the Anthropocene as an epoch, as Matthias Grotkopp writes, “tips the scales towards the illusion of a new normal, instead of framing it as a succession of crossed thresholds into the unknowable and unforeseeable.”[9]
It is that crossing of thresholds we need to be talking about, a crossing we are undertaking together, blindly so far, not the fabulous new era that isn’t.
*This article was slightly amended on March 23 to clarify that geology is not only “a reading of the past.” That is more accurately ascribed to the branch of geology called stratigraphy.
[1] Bruno Latour, Pandora’s Hope: Essays on the Reality of Science Studies (Harvard University Press, 1999), p. 71; and Joshua Malitsky, “Science and Documentary: Unity, Indexicality, Reality,” Journal of Visual Culture 11.3 (2012), p. 244.
[2] Anthropocene Curriculum, “Anthropocene Working Group,” https://www.anthropocene-curriculum.org/contributors/anthropocene-working-group, accessed March 21, 2024.
[3] Sigal Samuel, “Why Did Geologists Reject the ‘Anthropocene’ Epoch? It’s Not Rock Science,” Vox, March 20, 2024, https://www.vox.com/future-perfect/2024/3/7/24092675/anthropocene-climate-change-epoch-geology, accessed March 21, 2024.
[4] … refers to a “series of complex votes,” “continued rounds of voting and data analysis,”
[5] Erle Ellis, Letter to Anthropocene Working Group (AWG), Subcommission on Quaternary Stratigraphy, ICS, IUGS, July 12, 2023, https://anthroecology.org/wp-content/uploads/2023/07/ellis_AWG_resignation_2023_07_12.pdf, accessed March 21, 2024.
[6] Colin Waters, “Chair’s Column,” Newsletter of the Anthropocene Working Group 13: Report of Activities 2023, March 16, 2024, p. 4.
[7] See Damian Carrington, “Quest to Declare Anthropocene an Epoch Descends into Epic Row,” The Guardian, March 7, 2024, https://www.theguardian.com/science/2024/mar/07/quest-to-declare-anthropocene-an-epoch-descends-into-epic-row, accessed March 17, 2024; Alexandra Witze, “Geologists Reject the Anthropocene as Earth’s New Epoch—After 15 Years of Debate,” Nature, March 6, 2024, https://www.nature.com/articles/d41586-024-00675-8, accessed March 22, 2024; Alexandra Witze, “It’s Final: The Anthropocene is Not an Epoch, Despite Protest After Vote,” Nature, March 20, 2024, https://www.nature.com/articles/d41586-024-00868-1, accessed March 22, 2024.
[8] International Union of Geological Sciences, Facebook, March 21, 2024, https://www.facebook.com/iugspage, accessed March 21, 2024.
[9] Matthias Grotkopp, “Tipping the Scales: The Interfacing Worlds of Anthropocene: The Human Epoch,” Interfaces 50 (2023), https://journals.openedition.org/interfaces/8114, accessed March 21, 2024, p. 19.
Anthropocene is a reality. Personally I am an apocalyptic environmentalist. The main way to prevent the extinction of humankind is to discover our ignorance and to realize that humans are mammals therefore devouring the mammalian flesh is tantamount to cannibalism.