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Guest “Stick a fork in it” by David Middleton

This should “stick a fork” in the notion of an Anthropocene Epoch…

Gill co-authors report arguing Anthropocene should be a geological event, not an epoch

November 16, 2021 

Scientists studying how human activity alters the Earth use the term “Anthropocene” to describe a generalized period of time in which humanity has impacted the planet through landform and ecosystem alteration, species eradication, climate change and more. Yet Anthropocene has no concrete scientific definition, resulting in it being given several conflicting meanings that cause confusion among researchers and the general public.  

To help alleviate the ambiguity, some experts suggest that the Anthropocene should be defined as a formal epoch within the Geologic Time Scale. Jacquelyn Gill, however, contends that the Anthropocene should be considered a geological event, or significant transformation of the Earth marked in its geology. 

Gill, an associate professor of paleoecology and plant ecology at the University of Maine, and other researchers advocated for this argument in a Cambridge University-led paper published in the journal Episodes

Identifying the Anthropocene as an epoch could hinder scientists’ ability to understand, investigate and discuss how humans have altered the planet, according to Gill and her colleagues. Human action has altered the Earth for thousands of years at different scales and across numerous cultural practices, so restricting the Anthropocene to a specific period in time could limit the amount of activity to research and explore. 

As a geological event, however, the Anthropocene would encompass a broader variety of anthropogenic effects throughout human history. The label also more accurately reflects the diachronous and variable nature of human-influenced global change, according to researchers. A geological event would make the Anthropocene more useful across different disciplines as well, while still grounding its understanding in the geological record.


UMaine News

H/T to Mrs. Middleton for bringing this article to my attention. The Episodes paper is very well done and worth reading.

A practical solution: the Anthropocene is a geological event, not a formal epoch
by Philip L. Gibbard, Andrew M. Bauer, Matthew Edgeworth, William F. Ruddiman, Jacquelyn L. Gill, Dorothy J. Merritts, Stanley C. Finney, Lucy E. Edwards, Michael J. C. Walker, Mark Maslin and Erle C. Ellis

The Anthropocene has yet to be defined in a way that is functional both to the international geological community and to the broader fields of environmental and social sciences. Formally defining the Anthropocene as a chronostratigraphical series and geochronological epoch with a precise global start date would drastically reduce the Anthropocene’s utility across disciplines. Instead, we propose the Anthropocene be defined as a geological event, thereby facilitating a robust geological definition linked with a scholarly framework more useful to and congruent with the many disciplines engaging with human-environment interactions. Unlike formal epochal definitions, geological events can recognize the spatial and temporal heterogeneity and diverse social and environmental processes that interact to produce anthropogenic global environmental changes. Consequently, an Anthropocene Event would incorporate a far broader range of transformative human cultural practices and would be more readily applicable across academic fields than an Anthropocene Epoch, while still enabling a robust stratigraphic characterization.


The paper has a rather odd collection of coauthors. Former Secretary General of the International Commission on Stratigraphy (ICS) Stanley Finney and Lucy E. Edwards have written that the Anthropocene is more of a political, rather than geological concept. William Ruddiman has suggested that early human agriculture actually staved off the onset of the next Quaternary glacial stage and considers the notion of an Anthropocene Epoch to be redundant:

Other critics, notably William Ruddiman, a palaeoclimatologist at the University of Virginia in Charlottesville, have pushed for starting the Anthropocene when humans first began terrascaping Earth with agriculture thousands of years ago, or when they wiped out the megafauna of Australia and North America many millennia before 1950 (see W. F. Ruddiman Prog. Phys. Geogr. Earth Environ. http://doi.org/gd4shx; 2018). Some have argued against designating the Anthropocene at all, given that the Holocene has been marked by escalating human influences since the end of the last ice age.


While Erle Ellis and Mark Maslin have been rather zealous proponents of the official adoption of an Anthropocene Epoch in the Geologic Time Scale. Although, Ellis, a member of the Anthropocene Working Group (AWG), has been critical of the process:

Erle Ellis, a geographer at the University of Maryland, Baltimore County, and an AWG member, has criticized the committee’s plans for designating the start of the Anthropocene. “The AWG decided the timing of the boundary before deciding on the marker, not the other way around,” says Ellis.


The lead author, Phillip Gibbard is the current Secretary General of the ICS and a member of the AWG. The combination of Anthropocene proponents and opponents leads me to think that a compromise is in the works. This is from the paper’s conclusion:

Current usage of the term ‘Anthropocene’ conceals a wide range of conflicting scientific meanings that has caused confusion among scholars and the broader public with whom they engage. This situation is unlikely to change without a more precise and useful definition. Yet, efforts to understand and address Earth’s transformation through human social and cultural practices are fundamentally imperiled by continued efforts to define and formalize the Anthropocene as an official, rigidly constrained chronostratigraphic/ geochronologic interval in the GTS. A shift to a geological event framework is a solution that overcomes many of the problems with defining the Anthropocene. It
eliminates ambiguity in the use of the term and offers a way forward through conceptual and disciplinary barriers by freeing the concept from the constraints of geological formalization, as well as from its alignment with established time units within the Holocene Series/Epoch.

Gibbard et al., 2021

Figure 1 from the paper provides a conceptual timeline for how an Anthropocene Event could be a useful tool in connecting the human activities to the GTS.

Figure 1 from Gibbard et al., 2021

Apart from one glaring error, it’s not a bad concept. The glaring error is the notation of “Mass extinctions” over the past 100 years…

Earth Is Not in the Midst of a Sixth Mass Extinction
“As scientists we have a responsibility to be accurate about such comparisons.”

By Peter Brannen

JUNE 13, 2017

At the annual meeting of the Geological Society of America, Smithsonian paleontologist Doug Erwin took the podium to address a ballroom full of geologists on the dynamics of mass extinctions and power grid failures—which, he claimed, unfold in the same way.


Erwin is one of the world’s experts on the End-Permian mass extinction, an unthinkable volcanic nightmare that nearly ended life on earth 252 million years ago. He proposed that earth’s great mass extinctions might unfold like these power grid failures: most of the losses may come, not from the initial shock—software glitches in the case of power grid failures, and asteroids and volcanoes in the case of ancient mass extinctions—but from the secondary cascade of failures that follow. These are devastating chain reactions that no one understands. Erwin thinks that most mass extinctions in earth’s history—global die-offs that killed the majority of animal life on earth—ultimately resulted, not from external shocks, but from the internal dynamics of food webs that faltered and failed catastrophically in unexpected ways, just as the darkening eastern seaboard did in 2003.


“Many of those making facile comparisons between the current situation and past mass extinctions don’t have a clue about the difference in the nature of the data, much less how truly awful the mass extinctions recorded in the marine fossil record actually were,” he wrote me in an email. “It is absolutely critical to recognize that I am NOT claiming that humans haven’t done great damage to marine and terrestrial [ecosystems], nor that many extinctions have not occurred and more will certainly occur in the near future. But I do think that as scientists we have a responsibility to be accurate about such comparisons.”


The Atlantic

Apart from 86’ing “Mass extinctions” from the conceptual timeline, I would also drop the “-cene” from Anthropocene. The current naming convention applies “-cene” to Cenozoic Era epochs. Instead of the Anthropocene Event, I would call it, the Anthropolitan Event… Better yet… The Fabulous Anthropolitan Event!

‘Habitus’ (2013 – ongoing) is an art installation by Robyn Woolston (robynwoolston.com), commissioned by Edge Hill University, which announces the Anthropocene epoch, Vegas-style. AAPG Explorer.


Finney, Stanley C. & Lucy E. Edwards. “The “Anthropocene” epoch: Scientific decision or political statement?” GSA Today, 2016; 26 (3): 4 DOI: 10.1130/GSATG270A.1

Gibbard PL, Bauer AM, Edgeworth M, Ruddiman WF, Gill JL, Merritts DJ, Finney SC, Edwards LE, Walker MJC, Maslin M, Ellis EC.  “A practical solution: the Anthropocene is a geological event, not a formal epoch”.  Episodes -0001;0:-.  https://doi.org/10.18814/epiiugs/2021/021029

via Watts Up With That?

November 29, 2021