New Papers from the Anthropocene Working Group (part 5)

Jan Zalasiewicz et al., “Making the case for a formal Anthropocene Epoch: an analysis of ongoing critiques,” Newsletters on Stratigraphy 50:2 (2017)

What’s been needed to move forward the debate about formalizing the Anthropocene epoch as a new entry in the official Geologic Time Scale? A paper exactly like this one. Over the last five years a string of papers have been published critiquing the Anthropocene as a geological concept. They’ve contained substantive arguments and weaker arguments; they’ve added to and overlapped with one another. In this paper, the AWG members (with one notable additional contributor) systematise and respond to those critiques. It’s invaluable, clarifying work.

The paper identifies 21 distinct objections made on stratigraphic grounds to the stratigraphic use of the Anthropocene, collected from about ten earlier papers. The issue here is the categorisation of sedimentary rock layers, rather than anything else, so there’s no explicit response here to Malm’s and Moore’s “Capitalocene” and the like: the AWG don’t include among their 21 objections the old chestnut that the Anthropocene misrepresents the causes of historical change by treating the human species as a unified mass set apart from the rest of the planet. What they say does implicitly bear on the Capitalocene argument at several points, though.

The 21 objections are grouped into eight categories; they range from the overtly trivial (no. 2.1.4, that the Anthropocene ought instead to be called “the Atomic Age” because that name was used first) to the evidently weighty, like no. 2.3.3: is there any need for a new geological time unit set in “historically recent time”? The group’s response to the latter question is one of my favourite moments in the essay:

If we can now observe and record the global changes that are taking place, rather than infer them from the geological record, why is the corresponding stratigraphy still important and deserving of formal incorporation into the Geologic Time Scale? […] The significance of the Anthropocene lies in the fact that those observations and recordings are tied into, and gain their context and meaning from, the entire history of the Earth. […] The stratigraphic proxies within Anthropocene strata contribute directly to identifying and calibrating this most recent phase of Earth history. (p. 216)

The geological version of the Anthropocene lets us locate the contemporary crisis within the great sweep of Earth history, where it can’t help but belong. Talk about ties, or talk about calibration: either way, the present moment is materially and conceptually and irrevocably bound up with deep time.

My other favourite moment in the paper comes about because it sometimes seems there’s a fear that the Anthropocene is intended to do down or subordinate the Holocene epoch in some way. The AWG say that’s not the case at all. At the moment, the Holocene is open ended, but

defining a base for the Anthropocene provides completeness for our understanding of the Holocene, with both top and base defined. Such closure hence may be considered an advantage for the understanding of the Holocene, both stratigraphically and conceptually. On a global scale, this has been environmentally a highly stable epoch, strongly contrasting with the Anthropocene… (p. 210)

The argument about the beginning of the Anthropocene has always been just as much an argument about the end of the Holocene: it identifies a sundering, a burial, an invitation (if we suspend strict geological rationality for a moment) to mourning. Framing the Holocene epoch as a geological interval that runs from 9700 BCE to AD 1952 sounds strange, yes, but it’s a productive kind of strangeness.

The paper as a whole doesn’t really yield any ground to any of the Anthropocene’s stratigraphic critics. Its argument throughout is that the new epoch is a well-founded geological concept, and that none of the objections raised so far should block a full scale proposal to amend the Geologic Time Scale from moving forward for consideration.

Its recurring mantra is that the concept of the Anthropocene obeys all the normal rules of stratigraphic formalisation. Yes, of course the material evidence of a recent epoch-level change in the rock record is complicated and variable, but it’s there underfoot, not just a hypothesis about the future, and the geological record always complicated. Yes, the name is a funny one, but equally “to have the Silurian and Ordovician named after obscure ancient Welsh tribes has no apparent inherent logic”: “etymological purity” has never been required (pp. 208–9). The evidence for the Anthropocene shouldn’t be held to a standard of perfection that other chronostratigraphic units don’t reach. “There is no reason to treat these modern successions differently than the rest of the geological column. Chronostratigraphy continues to the present, rather than stopping at some arbitrary point in the geological past” (p. 216).

In fact, the AWG write, if the “rapid, major perturbations to […] geochemical cycles, biological communities and sedimentation” that are at issue had been caused by something other than human societies, their stratigraphic significance would be just as great, but they might “have been in some ways easier to analyze and categorize” (p. 221). I think that’s true. They imagine (pp. 214–15) a stratigrapher looking at the world seventy years after the Chicxulub bolide hit. Would she have thought it was too soon to say that a new chapter of Earth history had just begun?

With that in mind, then, is the Anthropocene a scientific concept, or is it instead a political one? That’s a false dichotomy, of course. The AWG’s response is straightforward and sensible:

It is clear that many of the phenomena connected with the Anthropocene are of societal, and hence political, importance. However, this does not mean that they cannot be treated objectively and scientifically analyzed, within the appropriate—in this case formal stratigraphic—framework. (p. 221)

So what’s next? The AWG’s report last autumn moved the process into its next stage. Now, “work is beginning to identify and select candidate GSSP sites”: actual places somewhere on Earth where the emblematic starting point of the Anthropocene might be fixed. Expect some results “in the next few years” (p. 221).