Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-18T13:56:41.108Z Has data issue: false hasContentIssue false

City-Strata of the Anthropocene

Published online by Cambridge University Press:  05 March 2020

Jan Zalasiewicz
Affiliation:
School of Geography, Geology, and the Environment, University of Leicester, LE1 7RH
Colin Waters
Affiliation:
School of Geography, Geology, and the Environment, University of Leicester, LE1 7RH
Mark Williams
Affiliation:
School of Geography, Geology, and the Environment, University of Leicester, LE1 7RH

Abstract

The fabric of a city represents a transformation of raw geological materials into a complex assemblage of new, human-made minerals and rocks such as steel, glass, plastics, concrete, brick, and ceramics. This activity has been considered in terms of an “urban metabolism,” with day-to-day inflows and outflows of people, food, water, and waste materials. Here we adopt a longer time-scale spanning years to millennia, related to geological time-scales but still meaningful for present and future generations of humans, and consider cities as sedimentary systems. In natural sedimentary systems, flows of materials are governed by natural forces such as climate and gravity, and leave physical records in, for instance, river-strata. In cities, the flows of geological materials needed for construction and reconstruction are directed by humans, and are largely powered by the fossil energy stored in hydrocarbons rather than by gravity or the sun. The resultant assemblages of anthropogenic rocks and minerals may be thought of as sedimentary (and/or trace-fossil) systems that can undergo fossilization and now exist on a planetary scale. Far more diverse than natural geological strata, they are also evolving much more rapidly, not least in terms of their growing waste products. Considering cities through such a perspective may become increasingly useful as they come to be influenced by, and need to adapt to, the changing conditions of the emerging Anthropocene epoch.

Type
The Anthropocene
Copyright
© Éditions EHESS 2019

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

This article was originally published in French as “Les strates de la ville de l’Anthropocène,” Annales HSS 72, no. 2 (2017): 329–51.

References

1 The logic behind this process is outlined in Zalasiewicz, Jan, The Earth after Us: What Legacy Will Humans Leave in the Rocks? (Oxford: Oxford University Press, 2008)Google Scholar.

2 A concise history of the concept of the Anthropocene is given in Will Steffen et al., “The Anthropocene: Conceptual and Historical Perspectives,” in “The Anthropocene: A New Epoch of Geological Time?” ed. Mark Williams et al., thematic issue, Philosophical Transactions of the Royal Society A 369, no. 1938 (2011): 842–67. The two key papers launching the concept in its modern sense are Crutzen, Paul J. and Stoermer, Eugene F., “The ‘Anthropocene,’Global Change Newsletter 41 (2000): 1718Google Scholar; and Crutzen, Paul J., “Geology of Mankind,” Nature 415 (2002): 23CrossRefGoogle ScholarPubMed.

3 A recent summary of the evidence can be found in Waters, Colin N.et al., “The Anthropocene Is Functionally and Stratigraphically Distinct from the Holocene,” Science 351, no. 6269 (2016): 137.CrossRefGoogle ScholarPubMed

4 Chakrabarty, Dipesh, “The Climate of History: Four Theses,” Critical Inquiry 35 (2009): 197222CrossRefGoogle Scholar; Bruno Latour, “Anthropology at the Time of the Anthropocene: A Personal View of What Is to Be Studied” (Washington: American Association of Anthropologists, 2014), http://www.bruno-latour.fr/sites/default/files/139-AAA-Washington.pdf.

5 Leclerc, Georges-Louis, Buffon, comte de, The Epochs of Nature, ed. and trans. Zalasiewicz, Jan, Milon, Anne-Sophie, and Zalasiewicz, Mateusz (Chicago: University of Chicago Press, 2018).CrossRefGoogle Scholar

6 Jordan, Douglas W. and Pryor, Wayne A., “Hierarchical Levels of Heterogeneity in a Mississippi River Meander Belt and Application to Reservoir Systems,” AAPG Bulletin 76, no. 10 (1992): 1601–24.Google Scholar

7 Williams, Market al., “Humans as the Third Evolutionary Stage of Biosphere Engineering of Rivers,” Anthropocene 7 (2014): 5763.CrossRefGoogle Scholar

8 And of course there are other, non-human empires: the geological systems around lakes, oceans, volcanoes, soils, coral reefs, and so on, can all be analyzed in these terms. Key texts outlining this approach include Reading, Harold G., ed., Sedimentary Environments: Processes, Facies and Stratigraphy (Hoboken: Wiley-Blackwell, 1996).Google Scholar

9 See the data provided by the Global Health Observatory: http://www.who.int/gho/urban_health/situation_trends/urban_population_growth_text/en/.

10 See the report by UN-Habitat: http://unhabitat.org/urban-themes/energy/.

11 Most popular articles on the Anthropocene make heavy use of city images, for instance Kolbert, Elizabeth, “Enter the Anthropocene: Age of Man,” National Geographic, March 2011, 6085Google Scholar. The first two volumes produced by the Anthropocene Working Group have also used city images for their covers, the first by day and the second by night: Williams, Market al., eds., “The Anthropocene: A New Epoch of Geological Time?” thematic issue, Philosophical Transactions of the Royal Society A 369, no. 1938 (2011)Google Scholar; Waters, Colin N.et al., A Stratigraphical Basis for the Anthropocene? (London: Geological Society of London, 2014)CrossRefGoogle Scholar. The cityscape of Shanghai appeared on the cover of the first stratigraphical analysis of the Anthropocene: Zalasiewicz, Janet al., “Are We Now Living in the Anthropocene?GSA Today 18, no. 2 (2008): 48.CrossRefGoogle Scholar

12 Urban metabolism is used as a mode of analysis in papers such as Kennedy, Christopher, Pincetl, Stephanie, and Bunje, Paul, “The Study of Urban Metabolism and Its Applications to Urban Planning and Design,” Environmental Pollution 159 (2011): 1965–73.CrossRefGoogle Scholar

13 Peter Haff has developed these ideas extensively and rigorously in Haff, Peter K., “Technology and Human Purpose: The Problem of Solids Transport on the Earth’s Surface,” Earth System Dynamics 3, no. 2 (2012): 417–31.CrossRefGoogle Scholar

14 In the sense used in Zalasiewicz, The Earth after Us.

15 Mielke, Hans-Jürgen, Wald und Politik. Die unendliche Geschichte des Berliner Teufelsberges (Berlin: Projekte-Verlag Cornelius, 2011).Google Scholar

16 Zalasiewicz, Jan, Waters, Colin N., and Williams, Mark, “Human Bioturbation, and the Subterranean Landscape of the Anthropocene,” Anthropocene 6 (2014): 39.CrossRefGoogle Scholar

17 The modern structures do not seem to be any more durable than the older buildings, as suggested by the vivid descriptions of the rapid decay of abandoned tower blocks in Weisman, Alan, The World without Us (London: Virgin Books, 2008).Google Scholar

18 Suess, Eduard, Der Boden der Stadt Wien: nach seiner Bildungsweise, Beschaffenheit und seinen Beziehungen zum Bürgerlichen Leben. Eine geologische Studie (Vienna: Wilhelm Braumüller, 1862)Google Scholar; Suess, , Der Boden der Stadt Wien und sein Relief. Geschichte der Stadt Wien (Vienna: Adolf Holzhausen, 1897).Google Scholar

19 J. R. Ford et al., “An Assessment of Lithostratigraphy for Anthropogenic Deposits,” in Waters et al., A Stratigraphical Basis, 55–89.

20 This is discussed in detail in Matt Edgeworth, “The Relationship between Archaeological Stratigraphy and Artificial Ground and Its Significance,” in Waters et al., A Stratigraphical Basis, 91–108, which argues for the use of the term “archaeosphere” to describe this kind of terrain, contrasting it with what archaeologists term “the natural,” that is, the undisturbed geological strata that lie below.

21 Hooke, Roger LeB. and Martín-Ducque, José F., “Land Transformation by Humans: A Review,” GSA Today 22, no. 12 (2012): 410.CrossRefGoogle Scholar

22 If one simplifies greatly and combines these with other global datasets, one can arrive at a rough estimate for the total mass of the Earth’s urban areas, including both functional and waste materials. According to one such calculation, this counts for some 11 trillion tons out of a total estimated mass of the Earth’s “physical technosphere” of around 30 trillion tons: Zalasiewicz, Janet al., “Scale and Diversity of the Physical Technosphere: A Geological Perspective,” The Anthropocene Review 4, no. 1 (2017): 922CrossRefGoogle Scholar. This figure implies that, spread out evenly over the Earth’s surface (both land and ocean), our city-material now weighs in at over 15 kilos per square meter. [See also the following, published since the original version of the present article was written: Terrington, Ricky L.et al., “Quantifying Anthropogenic Modification of the Shallow Geosphere in Central London, UK,” Geomorphology 319 (2015): 1534.]CrossRefGoogle Scholar

23 Hay, Carling C.et al., “Probabilistic Reanalysis of Twentieth-Century Sea-Level Rise,” Nature 517 (2015): 481–84.CrossRefGoogle ScholarPubMed

24 For example, Syvitski, James P. M.et al., “Sinking Deltas Due to Human Activities,” Nature Geoscience 2 (2009): 681–86.CrossRefGoogle Scholar

25 Compare the “Great Acceleration” graphs, revised and updated in Steffen, Willet al., “The Trajectory of the Anthropocene: The Great Acceleration,” The Anthropocene Review 2, no. 1 (2015): 8198CrossRefGoogle Scholar, with the patterns of Anthropocene stratigraphic trends set out in Waters et al., “The Anthropocene Is Functionally and Stratigraphically Distinct.”

26 Thomas Brinkhoff, “Major Agglomerations of the World,” 2017, http://www.citypopulation.de/cities.html.

27 Zalasiewicz, Janet al., “The Technofossil Record of Humans,” The Anthropocene Review 1, no. 1 (2014): 3443.CrossRefGoogle Scholar

28 Even though older cities, such as Paris and London, are in large part made of an intermeshed filigree of Holocene and Anthropocene components, these are often readily distinguishable on the basis of their distinctive materials and artifacts.

29 With excellent air conditioning, at least in the termite-built structures. See Bordy, Emese M.et al., “Advanced Early Jurassic Termite (Insecta: Isoptera) Nests: Evidence From the Clarens Formation in the Tuli Basin, Southern Africa,” Palaios 19, no. 1 (2004): 6878.2.0.CO;2>CrossRefGoogle Scholar

30 Mark Williams et al., “Underground Metro Systems: A Durable Geological Proxy of Rapid Urban Population Growth and Energy Consumption during the Anthropocene,” in The Routledge Companion to Big History, ed. Craig Benjamin, Esther Quaedackers, and David Baker (London: Routledge, forthcoming).

31 Peter K. Haff, “Technology as a Geological Phenomenon: Implications for Human Well-Being,” in Waters et al., A Stratigraphical Basis, 301–9.

32 Rathje, William and Murphy, Cullen, Rubbish! The Archaeology of Garbage (Tucson: The University of Arizona Press, 2001).Google Scholar

33 Those fossilized cities will mainly consist of foundations, cellars, metro systems, pilings, and so on, together perhaps with lower stories in some cases. Most of the superstructure will be in the erosional realm, except in the rare cases where it will be buried by a sudden, overwhelming inrush of sediment, just as Pompeii was buried by volcanic ash in Roman times.

34 Irabien, María Jesúset al., “Chemostratigraphic and Lithostratigraphic Signatures of the Anthropocene in Estuarine Areas from the Eastern Cantabrian Coast (N. Spain),” Quaternary International 364 (2015): 196205.CrossRefGoogle Scholar

35 Zalasiewicz, Janet al., “The Geological Cycle of Plastics and Their Use as a Stratigraphic Indicator of the Anthropocene,” Anthropocene 13 (2016): 417.CrossRefGoogle Scholar

36 Among numerous examples, see Gregory, Murray R., “Environmental Implications of Plastic Debris in Marine Settings: Entanglement, Ingestion, Smothering, Hangers-On, Hitch-Hiking and Alien Invasions,” Philosophical Transactions of the Royal Society B 364, no. 1526 (2009): 2013–25.CrossRefGoogle ScholarPubMed

37 Eriksen, Marcuset al., “Plastic Pollution in the World’s Oceans: More Than 5 Trillion Plastic Pieces Weighing Over 250,000 Tons Afloat at Sea,” Plos One 9, no. 12 (2014): https://doi.org/10.1371/journal.pone.0111913.CrossRefGoogle ScholarPubMed

38 Jambeck, Jenna R.et al., “Plastic Waste Inputs from Land into the Ocean,” Science 347, no. 6223 (2015): 768–71.CrossRefGoogle ScholarPubMed

39 See the recent study conducted by Queen Mary University of London, “Assessing the Risk of Pollution from Historic Coastal Landfills,” 2017, http://www.qmul.ac.uk/media/news/items/hss/176675.html; Spencer, Kate L. and O’Shea, Francis T., “The Hidden Threat of Historic Landfills on Eroding and Low-Lying Coasts,” ECSA Bulletin 63 (2014): 1617.Google Scholar