Pitfalls and potentials in dating the onset of the Anthropocene

Just when (and how) did humans begin influencing the planetary system? Recent posts on this blog – notably those by Zev and Stephen on creation myths, Noah’s on cosmopolitanism, and David’s on Holocene climate – have spurred me to think about how delimiting a chronological date on the start of the Anthropocene influences how we think about habitability. Here I present some musings.

As initially conceived by non-archaeologists, the start of the Anthropocene was placed somewhere in the past two hundred or so years, coeval with the industrial revolution and the great acceleration (Steffen et al., 2011, Crutzen, 2002) (although see (Ruddiman, 2003)). However, archaeologists have begun to weigh in, some of whom envision an earlier start date for the Anthropocene.  One of the more contentious aspects is identifying proxy measures of significant change (so-called golden spikes). A series of articles in the journal Anthropocene, many of which are in press and derived from a 2013 Society for American Archaeology symposium (Balter, 2013, Braje and Erlandson, 2014), provide a variety of starting points for the time at which humans can be said to have become a dominant factor. The arguments for each are varied, but tend to emphasize either the visibility of past impacts, or the kinds of impacts that are envisioned. These papers provide a great starting point for anyone interested in archaeology’s contributions to Anthropocene discourse, and are a wonderful introduction to the kinds of data and methods available for investigating local, regional, and global impacts.  I’ll just point out a few highlights here.

Several authors suggest that the onset of the Anthropocene should be set coterminous with the Holocene. They argue that not only does this relieve the need to derive new nomenclature, it emphasizes the long history of intensive human-world interactions, and eliminates the need for seeking clear-cut golden spikes. Smith and Zeder (2014), for example, note that the boundary of the Pleistocene-Holocene is marked in many parts of the world by incipient domestication of plants and animals, and the emergence of “ever expanding regionally tailored agricultural economies and a complex unfolding history of ever increasing management and modification of the biosphere over the past 10,000 years” (pp. 5). Thus, setting the starting date then would acknowledge the near global scale of landscape modification (by farmers). I would note that in at least some cases, domestication appears to have been an unintended consequence as populations were attempting to maintain a status quo in the context of social and environmental change, something that we should all consider in future planning for interventions in the Anthropocene.  Erlandson and Braje (2014) note that there were, in fact, many “tipping points” or moments of “acceleration” that we could hang the Anthropocene on, going back to the diaspora of anatomically modern humans 70,000 years ago out of Africa wherein “a unique human biology, a propensity for technological innovation, and shared adaptive resilience may underlie the development of agriculture and complex societies in far-flung parts of the world within just a few millennia, a virtual eyeblink in geological time” (Erlandson and Braje 2014, pp. 5). They too, however, argue that it is only during the Holocene that these impacts may be globally visible. Even though such changes may be difficult to identify in, say, atmospheric carbon concentrations, other sorts of proxies are plainly visible: contemporary forest composition, anthropogenic soils, architecture, tools, extinction events, and the like.

Foley et al. (2013) take a slightly different tack.  They accept the presentist (AD 1780) Anthropocene, but introduce the concept of the Paleoanthropocene as the “time interval before the industrial revolution during which anthropogenic effects on landscape and environment can be recognized but before the burning of fossil fuels produced a huge crescendo in anthropogenic effects” (Foley et al 2013, p. 84). The start of the Paleoanthropocene is thus an intentionally open ended question, with an emphasis on local or regional developments. They delineate several reasons why identifying anthropogenic input in the past is difficult, including inherent biases in the preserved data, the dampening effects of environmental sinks, and the different temporal and spatial scales in which landscape management and past technologies and practices were distributed across the landscape. There are, of course, many other dates that have been proposed (see Erlandson and Braje 2014: 5-6).

So, does the debate over the origins of the Anthropocene matter? A common rhetorical device in archaeological narratives (and most Western, linear histories) is the use of stages separated by turning points, typically referred to as “revolutions” (e.g., Neolithic revolution, industrial revolution, etc.).  Clive Gamble (2007) argues that revolutions are ultimately about delimiting origin points. Origins serve to establish a network of metaphors, analogies, and dualisms that organize observations for the sake of explanation. Origins thus are used to explain modern conditions, while at the same time separate modern from pre-modern on the basis of different networks. Commonly, origins enable a view of the modern world that is a product of a history of ascendancy / transformation / degradation / reclamation / failure (pick your favorite), while the ancient world is one in which humans were responders to change. In this regard, I see potential pitfalls in how we date the onset Anthropocene which mirror Noah’s risks of cosmopolitanism, particularly the risk of certainty of the composition and ordering of the cosmos. Indeed, Braje and Erlandson are well aware of the origin issues for public opinion and policy making, writing that a “post-Industrial Revolution starting date may suggest, to the uninitiated at least, that everything that came before was ‘natural.’”

Certainly, it could be argued that determining the start of the Anthropocene is simply a matter of empirical observation (see http://publishingarchaeology.blogspot.com/2014/01/are-archaeologists-welcome-in.html). The question emerges, then, what kinds of transformations? To date, most “revolutions” or origins for the Anthropocene are coincident with apparent transformations in food production and resource exploitation (e.g. farming in the early Holocene, expansive globalism with the rise of nation states, the intensive burning of fuels for power), each of which effectively mirror our own concerns (When did we begin to dominate or interanimate with the “natural”? When did we create social organizations that were vulnerable to external landscape pressure? And the like).  Often missing are alternative histories, such as the numerous hunter-gatherer communities who were globally coeval with farmers, and were in some cases equally responsible for massive landscape change. Although they perhaps do not fit a neat linear history, hunter-gatherers or other kinds of communities require us to think critically about our preconceptions of what habitability takes: Are nature-culture relations the same in hunter-gatherer communities as in farming communities? Further, do all farming communities have fundamentally the same relations with nature? Do different kinds of communities / ontologies / cosmologies provide for different modes of vulnerability or resiliency?  Is it the case that ancient communities responded to environmental change, or could they envision alternative strategies?  There are no easy answers to these questions, but I suggest we should keep them in mind lest we should explain only that which we think exists (or is relevant).

So, just when (and how) did humans begin influencing the planetary system? Determining the point at which humans became a dominant factor is “simply” an empirical question, depending on how we determine what being dominant means at the appropriate temporal and spatial scales. However, how we envision the origins of the Anthropocene influences the kinds of collective (cosmopolitan?) pasts and futures we can imagine for ourselves, which in turn may influence public opinion and policy (see Braje and Erlandson 2014).

References

  1. Balter, M. 2013. Archaeologists Say the ‘Anthropocene’ Is Here—But It Began Long Ago. Science, 340, 261–262. DOI: 10.1126/science.340.6130.261.
  2. Braje, T. J. & Erlandson, J. M. 2014. Looking forward, looking back: Humans, anthropogenic change, and the Anthropocene. Anthropocene, DOI: 10.1016/j.ancene.2014.05.002.
  3. Crutzen, P. J. 2002. The “Anthropocene”. Journal de Physique IV, 12, 1–5.
  4. Foley, S. F., Gronenborn, D., Andreae, M. O., Kadereit, J. W., Esper, J., Scholz, D., Pöschl, U., Jacob, D. E., Schöne, B. R., Schreg, R., Vött, A., Jordan, D., Lelieveld, J., Weller, C. G., Alt, K. W., Gaudzinski-Windheuser, S., Bruhn, K.-C., Tost, H., Sirocko, F. & Crutzen, P. J. 2013. The Palaeoanthropocene: the beginnings of anthropogenic environmental change. Anthropocene, 83-88. DOI: 10.1016/j.ancene.2013.11.002.
  5. Gamble, C. 2007. Origins and revolutions: human identity in earliest prehistory, New York, Cambridge University Press.
  6. Ruddiman, W. F. 2003. The Anthropogenic Greenhouse Era Began Thousands of Years Ago. Climatic Change, 61, 261–293.
  7. Smith, B. D. & Zeder, M. A. 2014. The onset of the Anthropocene. Anthropocene, DOI: 10.1016/j.ancene.2013.05.001.
  8. Steffen, W., Grinevald, J., Crutzen, P. & McNeill, J. 2011. The Anthropocene: conceptual and historical perspectives. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 369, 842–867. 10.1098/rsta.2010.0327.
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