On Terra Incognita: Crutzen’s “Geology of Mankind” (part 2)

Part 1

Here’s the second part in an occasional series of fossickings through the great talismanic paper on the Anthropocene, Paul Crutzen’s “Geology of Mankind”— now up to 1877 citations on Google Scholar but not previously, as far as I know, the subject of anything like a detailed close reading.


Intertext. “Geology of Mankind” is very closely related to a short paper simply called ‘The “Anthropocene”’ that was published in the IGBP Global Change Newsletter for May 2000. The IGBP—the International Geosphere–Biosphere Programme—was the large Earth system science research network within which Crutzen held a senior role. It was at an IGBP conference in February 2000 that he had had his fabled Eureka moment, and come up with the word Anthropocene. The Newsletter, which at this stage had the air of having been put together on somebody’s desktop, was the IGBP’s in-house journal.

In other words, ‘The “Anthropocene”’ represents almost the very earliest stage of Crutzen’s thinking about the proposed new epoch. It’s a somewhat less polished piece of writing than “Geology of Mankind” (which appeared in January 2002), but the substance of the two papers is much more alike than different. Most of the empirical data referred to are identical. GP Marsh, Antonio Stoppani, Vladimir Vernadsky and Pierre Teilhard de Chardin are identified as antecedents in both papers. Probably most sentences in each paper have a direct analogue somewhere in the other one, though not in the same order. Crutzen must have written “Geology of Mankind” with his earlier paper open in front of him.

But there are differences too. Some are just the consequence of the Newsletter’s and Nature’s different house styles. “The release of SO2, globally about 160 Tg/year to the atmosphere…” in 2000 becomes, in 2002, “…160 million tonnes of atmospheric sulphur dioxide emissions per year.” Other alterations, though, have more to tell us.

We can understand “Geology of Mankind” better by collating it against ‘The “Anthropocene.”’ The changes that Crutzen made will let us track the evolution of his thinking in the two years after he coined the word Anthropocene.


Stoermer. The most obvious difference between the two papers is that “The ‘Anthropocene’” is signed both by Crutzen and by the freshwater ecologist Eugene F. Stoermer. It’s always been obvious that Crutzen, rather than Stoermer, was the energising force behind that first article. Crutzen “invited [Stoermer] to co-sign” it, Ian Angus has reported, because Stoermer had already used the word Anthropocene back in the 80s, but Stoermer “took no further part in Anthropocene discussions” (Facing the Anthropocene, pp. 33, 234)

But things are just slightly more complicated than that. The Newsletter article includes two citations of a book and a paper by Stoermer. Like “Geology of Mankind,” it tentatively associates the beginning of the Anthropocene with “Watt’s invention of the steam engine in 1784,” mainly on the basis that that’s when global greenhouse gas concentrations started (so it claims) to rise. But the Newsletter article adds that “about at that time, biotic assemblages in most lakes began to show large changes,” and Stoermer’s work is cited as a source for that observation. That additional sentence, unlike nearly all the empirical evidence adduced in the Newsletter article, isn’t carried over into “Geology of Mankind.”

It’s possible that Crutzen wrote the whole of “The ‘Anthropocene’” himself, and included references to Stoermer’s research before inviting him to co-sign it. Conversely, it’s conceivable that there was after all quite a bit of collaboration between the two named authors, at least on one point: the whole business of suggesting the late eighteenth century as a starting point for the Anthropocene could owe more than has been realised to Stoermer’s ideas. But something in the middle seems much the most likely: that Crutzen sent Stoermer a draft that already included the allusion to Watt and 1784, then Stoermer, in agreeing to co-sign it, added in references to his own research.

There are two bits of evidence for that hypothesis. Firstly, Crutzen’s later omission of the reference to lake biota from “Geology of Mankind.” Secondly, a little infelicity in an earlier paragraph of ‘The “Anthropocene,”’ where examples of anthropogenic global change are listed. The penultimate sentence of that paragraph begins: “Finally, mechanized human predation (‘fisheries’) removes more than 25% of the primary production of the oceans in the upwelling regions” (my emphasis). Then, tacked on to that “final” observation, there’s another sentence: “Anthropogenic effects are also well illustrated by [lake biota]”—after which those same writings by Stoermer are referenced again. That’s exactly what the combination of last-minute co-authorship and slightly indifferent copy-editing looks like.

There are probably still emails on a server somewhere that would definitively resolve this small and not very interesting puzzle in the history of science. But one thing revealed by collating “Geology of Mankind” with “The ‘Anthropocene’” is the discreet discarding of what I take to be Stoermer’s two contributions to the earlier paper. It’s a minor irony that stratigraphic signals from freshwater lakes might yet end up being adopted by the ICS as the definitive marker of the birth of the Anthropocene.


“The role of mankind.” Here’s a more telling difference between the two papers. First, here from ‘The “Anthropocene”’ is the very first use of the word Anthropocene (the title excepted) in the contemporary tradition:

[I]t seems to us more than appropriate to emphasize the central role of mankind in geology and ecology by proposing to use the term “anthropocene” for the current geological epoch.

And here’s the parallel passage in “Geology of Mankind,” again the word’s first appearance in the paper:

It seems appropriate to assign the term “Anthropocene” to the present, in many ways human-dominated, geological epoch, supplementing the Holocene—the warm period of the past 10–12 millennia.

The lowercasing of “anthropocene” in 2000 is one of a number of signals that Crutzen wasn’t writing as a stratigrapher: standard stratigraphic practice is always to capitalise the names of geological intervals.

More significantly, the first paper presents the Anthropocene as above all a counter-Copernican concept. Its purpose is to emphasize the centrality of “mankind” to modern Earth system processes. That means that its name is more or less the most important thing about it: if it wasn’t called “the anthropocene,” there wouldn’t be much to it.

In “Geology of Mankind,” the movement towards a different way of using the word has already begun. The new epoch is “in many ways human-dominated,” which is not quite the same thing as having humans at its “centre.” And Crutzen’s focus is now a little less on the humanness of the new epoch, and a little more on its difference from the Holocene. The name is appropriate (it now seems) because human influences explain how divergence from the Holocene has taken place, rather than because the Earth system as a whole has been humanised. Those are precisely the tendencies in the understanding of the Anthropocene that will be taken much, much further in the stratigraphic tradition.

There’s something else there too: the Anthropocene as a supplement to the Holocene. More on that ambiguous turn of phrase another time.