Will Steffen et al., “Stratigraphic and Earth System Approaches to Defining the Anthropocene,” Earth’s Future 4 (2016), 324–45
And still they come. Actually, this paper by AWG members came out before the results of the vote on formalization, but I hadn’t had an opportunity to write about it until now. It’s another big overview paper.
Earth System science is the interpretation of the planet as a single integrated complex system. It’s a single system because the biosphere and all the parts of the geosphere mutually shape one another—and because it’s a single system, it’s prone to undergo relatively well-defined state shifts from one functional regime to another, whenever certain tipping points are crossed. Stratigraphy, the science of the planet’s “book of records,” gives historical depth to Earth System scholars’ theorising about the geobiochemical drives that hold the planet together, drives that are nowadays ceaselessly monitored on this satellite-encircled globe.
Stratigraphy and Earth System science have become closely and productively aligned, Steffen et al. say. That’s true, of course. And it’s a useful prompt to clarify something that I wrote rather carelessly here a few weeks ago. I said in this post that the “distinction between the Earth Systems version of the Anthropocene and the stratigraphic version of the Anthropocene” is pivotal to my whole account of the new epoch, because that distinction marks “a break from human-centred theories of agency.”
So are Earth Systems science and stratigraphy fundamentally distinct, or are they convergent? Well, the distinction that I meant to draw wasn’t really between the two disciplines at all, but instead between the earth-scientific account of the Anthropocene that generally prevailed before 2008, and the one that’s emerged since then. As Steffen et al. themselves put it in this new paper (p. 334), in Crutzen’s earliest essays and the Global Change and the Earth System IGBP synthesis report, “a major shift in the state of the Earth System was proposed on the basis of direct observations of changes in the Earth System, without specific reference to evidence in the stratigraphic record.” When Jan Zalasiewicz and co. started to work through the implications of the fact that “[formal] recognition of the Anthropocene as an epoch following the Holocene necessitates that the proposal be grounded in the Geologic Time Scale” (this week’s paper again, p. 325)—that’s when the idea of the Anthropocene came directly into contact with the immensities of deep time. And for me, that’s when the discourse on the Anthropocene began to take on its full revolutionary force.
In short, not Earth System science versus stratigraphy, but Earth Systems-without-stratigraphy versus Earth Systems-with-stratigraphy. That’s the distinction I’m really interested in.
When this week’s paper gets down to brass tacks (or rather: golden spikes), the relationship between Earth Systems thinking and stratigraphy turns out largely to be the relationship between two somewhat different ways of drawing boundaries. Higher-level divisions within the Geologic Time Scale should mostly coincide with state shifts in the Earth System, but lower-level divisions needn’t do so. And even those higher-level divisions are often formally defined by some paleontological change that’s of strictly specialist interest, which stands in metonymically for the larger shift. Conversely, major Earth System state shifts are often, but not necessarily, represented by divisions in the Geologic Time Scale. (This paper perhaps slightly underplays that fact, which Stanley Finney has sought to make much of in arguing against the formalization of the Anthropocene:
A number of very significant, long-term geological events recorded by extensive rock records and reflecting major upheavals in the Earth system are not represented by units in the ICS International Chronostratigraphic Chart/Geologic Time Scale, yet they are widely used by the geological community to convey the history of the Earth. These include Grenvillian, Variscan, Alpine- Himalayan and Snowball Earth, among others. (p. 27)
…so why shouldn’t the Anthropocene experience the same fate, Finney thinks?)
The paper’s style is quite characteristic of its lead author, Will Steffen. It’s fairly explicitly concerned with public policy, and it seems to me broadly dualistic in orientation, much concerned with “human pressures on the Earth System.” References like that to humans having an impact on the system as if from the outside have seemed to many other writers precisely antithetical to the idea of the Anthropocene.
That dualism comes out most notably in a lengthy and intriguing, but I think quite misleading, distinction between the “Holocene envelope of natural variability” on the one hand and the “Holocene basin of attraction”on the other—the latter being “a state of the Earth System that is still recognizable structurally and functionally as being the Holocene and within which negative feedbacks are still dominant,” but which somehow isn’t the Holocene proper. Given that “early agriculture” is said to have pushed the system outside the “envelope,” so that it only remained inside the larger “basin,” the paper seems to imply that pretty much the whole of the actual, historical Holocene was outside the “Holocene envelope of natural variability.” In other words, it appears to be distinguishing in a slightly muddled way between the real Holocene and an imaginary or hypothetical Holocene-minus-humans, which doesn’t seem to me like an especially useful avenue to go down.
But what’s really admirable about this paper, for me, is the force of its emphasis on the insight that “the [Earth] system is in a strongly transient phase,” that what we’ve seen of the Anthropocene so far is “not […] a stable state but […] a trajectory away from the Holocene” (pp. 336–37). It’s a continuous mobility. A becoming, not a state of affairs. A flight with no landing yet in view. That’s why I’ve argued that environmental politics today should be a practice of working within, and trying to inflect, a change of state that will inevitably outlast anybody’s lifespan, and why green politics shouldn’t be an illusory pursuit of an achieved state of “sustainability.” A centuries-long transience: that’s the challenge of the birth of the Anthropocene.
Made Ground 