The Anthropocene

The year 2018 ended with the perils of climate change once again emphasized, italicized, and publicized with the November IPCC report on 1.5 degree warming.  The findings of that report were disturbing; the window of opportunity for action to prevent dangerous warming was now less than 12 years away—2030. This announcement was quickly followed by the Katowice COP24 Climate Summit, during which the world’s second largest greenhouse gas emitter, the United States, sided with other petropowers, including Kuwait, Saudi Arabia, and Russia, in rejecting the language of the IPCC report regarding the severity of climate change.  

It was left to a Swedish teenager, 16 year-old Greta Thunberg, to remind the delegates that ethical imperatives of intergenerational equity demanded immediate action, a statement she repeated at the recently concluded Davos World Economic Forum.  Punctuating the forum’s heightened emphasis on environmental issues, Sir David Attenborough declared “The Holocene has ended. The Garden of Eden is no more. We have changed the world so much that scientists say we are in a new geological age: the Anthropocene, the age of humans.”1

An onrushing confluence of forces, iconically represented as the “Great Acceleration” 2,3  beginning in the 1950’s, characterizes the Human Age, the Anthropocene. The Anthropocene is the epoch in which humanity has become a global geophysical force4, capable of appropriating significant proportions of net primary production, modifying essential biogeochemical flows of nitrogen and phosphorus, elevating greenhouse gas concentrations to levels unseen during the Holocene, and altering land use on a scale that imperils biodiversity at levels rivaling the five past great extinction events. The rate of change in Earth System functions may be approaching or surpassing planetary thresholds,5with profound, intergenerational implications for human well-being.3,6  The communication of these changes extends well beyond that of perhaps the best known and publicized change, “global warming.”  The imperative of the Anthropocene demands a much broader understanding of anthropogenic global change and the recursive nature of such change7 beginning with a renewed emphasis on the critical role of the geosciences in understanding and addressing the challenges of the Anthropocene. 

The Anthropocene concept has become a term with as many emergent properties as those of the Earth System it represents8. These properties include considerations as varied as defining the Anthropocene in terms of the Geological Time Scale,9 rethinking globalization and world history in terms of “breaching the wall between human and natural history”10, and global inequality and social justice11.  The breadth of contemporary discussion regarding the Anthropocene encompasses scientific, anthropological, social, artistic and economic, historical, and paleontological points of view.12 Research and publication of articles involving the term “Anthropocene” has been a growth industry; between 2000-2015 citations number well over 8,000 8 and the total number of articles has grown exponentially in nearly the same period.13

Despite the widespread use of the Anthropocene term in and out of academia, the Anthropocene is not yet an officially defined geological unit within the Geological Time Scale.  Formal designation of the Anthropocene as a new unit of the GTS, defined via a Global Stratotype Section and Point (GSSP), or stratigraphic signal has yet to be approved by international geological sciences governing bodies.  However, on May 21, 2019, the Anthropocene Working Group, established to study this proposed designation, voted to affirm the Anthropocene as a formally defined geological unit, 

              “… (i)ts beginning would be optimally placed in the mid-20th century, coinciding with the array of geological proxy signals preserved within recently accumulated strata and resulting from the ‘Great Acceleration’ of population growth, industrialization and globalization; the sharpest and most globally synchronous of these signals, that may form a primary marker, is made by the artificial radionuclides spread worldwide by the thermonuclear bomb tests from the early 1950s.”14

The details of the official proposal are being developed by the AWG, and must be approved by the AWG, its parent bodies, and finally, the Executive Committee of the International Union of Geological Sciences.  

References

  1. https://www.theguardian.com/tv-and-radio/2019/jan/21/david-attenborough-tells-davos-the-garden-of-eden-is-no-more (Accessed February 11, 2019)
  2. Steffen, W., Broadgate, W., Deutsch, L., Gaffney, O., Ludwig, C., 2015. The trajectory of the Anthropocene: the Great Acceleration. Anthropocene Rev. 2, 81–98.
  3. Will Steffen, Johan Rockström, Katherine Richardson, Timothy M. Lenton, Carl Folke, Diana Liverman, Colin P. Summerhayes, Anthony D. Barnosky, Sarah E. Cornell, Michel Crucifix, Jonathan F. Donges, Ingo Fetzer, Steven J.Lade, Marten Scheffer, Ricarda Winkelmann, Hans Joachim Schellnhuber,  Trajectories of the Earth System in the Anthropocene, Proceedings of the National Academy of Sciences Aug 2018, 201810141; DOI:10.1073/pnas.1810141115
  4. Steffen, W., Crutzen, P.J., McNeill, J.R., 2007. The Anthropocene: are humans now overwhelming the great forces of Nature? Ambio 36, 614–621.
  5. Rockstrom, et al., Planetary Bounaries:  Exploring the Safe Operating Space for Humanity, Ecology and Society 14(2):32 [online] URL:  http://www.ecologyandsociety.org/vol14/iss2/art32/
  6. Hansen J, Kharecha P, Sato M, Masson-Delmotte V, Ackerman F, et al. (2013) Assessing “Dangerous Climate Change”: Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature. PLOS ONE 8(12): e81648. https://doi.org/10.1371/journal.pone.0081648
  7. Bougleux, E., Brandhuber, A., Ellis,E.C., Honig, T., Jeremijenko, N., “Anthropogenic Landscapes,” 2014.  https://www.anthropocene-curriculum.org/pgaes/root/campus-2014/anthropogenic-landscapes/
  8. Brondizio, E. S., K. O’Brien, X. Bai, F. Biermann, W. Steffen, F. Berkhout, C. Cudennec, M. C. Lemos, A. Wolfe, J. Palma- Oliveira, and C.-T. A. Chen. 2016. Re-conceptualizing the Anthropocene: a call for collaboration. Global Environmental Change 39:318-327. http://dx.doi.org/10.1016/j.gloenvcha.2016.02.006 
  9. Zalasiewicz, J., et al. 2017. The Working Group on the ‘Anthropocene’: Summary of evidence and recommendations. Anthropocene, v.19, pp.55–60. 
  10. Chakrabarty, D. (2009). The Climate of History: Four Theses. Critical Inquiry, 35(2), 197–222.doi:10.1086/596640
  11. Parks, B. C., & Roberts, J. T. (2010). Climate Change, Social Theory and Justice. Theory, Culture & Society, 27(2-3), 134–166.doi:10.1177/0263276409359018) Crutzen, P.J. 2002. Geology of mankind:  the Anthropocene.  Nature 415, 23
  12. Living in the Anthropocene: Earth in the Age of Humans Edited by W. John Kress and Jeffrey K. Stine. Smithsonian, (208p) ISBN 978-1-58834-601-8
  13. Chin, A., Gillson, L., Quiring, S. M., Nelson, D. R., Taylor, M. P., Vanacker, V., & Lovegrove, D. 2016.  An evolving Anthropocene for science and society. Anthropocene, Vol. 13, p1-3. 10.1016/j.ancene.2016.05.002
  14. http://quaternary.stratigraphy.org/working-groups/anthropocene/