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also by other geologists, archaeologists, biologists, atmospheric
chemists, and social scientists. Finally, it must be noted that with
1945 as the beginning, it would be a geologic time unit that pres-
ently has a duration of one average human life span.
POLITICAL STATEMENT
When we explain the fundamental difference of the
Anthropocene from the chronostratigraphic units established by
the International Commission on Stratigraphy to proponents for
its recognition, they often reply that the human impact on the
Earth system must be officially recognized, if for no other reason
than to make the public and governmental agencies aware of that
impact. Or, as the editorial in Nature (2011) argued, official recog-
nition would encourage cross-disciplinary science and a
“mindset” to understand and to take control of the current trans-
formation. However, it is political action that is required to meet
the ultimate goals of ameliorating human impact, which raises the
question of the ICS making a political statement. Pope Francis has
spoken out about the human-induced impact on the Earth
system—so too have leaders of many nations, the United Nations,
and numerous non-governmental organizations. In California,
Governor Jerry Brown has initiated and promoted many legisla-
tive actions with the goal of ameliorating human-induced impact.
Is the role of the ICS to make such a political statement? Would
official recognition of the term Anthropocene as a unit of the ICS
Chart realistically have any effect on promoting cross-disciplinary
science or recognizing that we are in the driver’s seat as Nature
editorialized? Or, is that not already the case?
The evolution of vascular land plants and their spread across
the continents from late in the Devonian to early in the Permian
completely altered Earth’s surface, left a significant stratigraphic
record, and dramatically altered CO2 and O2 concentrations in
the atmosphere and oceans far greater than humans are projected
to do (Berner and Canfield, 1989; Berner, 1998). Yet there is no
drive to name a unit in the ICS Chart that formally recognizes
that profound and irreversible change to the Earth system.
Perhaps promotion of the Anthropocene is anthropocentric as
well as political?
The “Atomic Age,” a term coined by The New York Times jour-
nalist William L. Lawrence in September 1946, has an identical
boundary and content to the Anthropocene proposal of
Zalasiewicz et al. (2015). By rights, the Atomic Age has nomencla-
tural priority. If the Anthropocene is not a political statement,
those who value priority should prefer the Atomic Age.
CONCLUSIONS OR THE WAY FORWARD
No formal, written proposal has yet been submitted by the
Anthropocene working group to the ICS Subcommission on
Quaternary Stratigraphy. Until that happens, the ICS and the
Quaternary Subcommission have nothing to consider, in spite of
all that has been published by the members of the working group
and by others in the scientific and public media. Assuming a
formal proposal is made that recommends approval of an
Anthropocene unit and boundary definition, that proposal will
have to provide a detailed description of the stratigraphic content
of the unit and show correlation of the lower-boundary GSSP to
lake cores, ice cores, and other stratigraphic records from
geographically widespread locations. It should also address
questions on the concept, basis, and stratigraphic utility of the GSA TODAY | www.geosociety.org/gsatoday
unit, such as those raised here and by Finney (2014), Head and
Gibbard (2015), and Walker et al. (2015). It must consider the
rank of the unit in light of the fact that its duration is that of an
average human lifespan. Lastly, such a proposal should recognize
that events of a proposed Anthropocene are those directly
observed and precisely dated with human chronometers and
calendars, and would not be interpreted from its marginal and
impoverished stratigraphic record. The fundamental question
that should be addressed in the proposal is this difference between
the character of the Anthropocene and that of the chronostrati-
graphic units of the ICS chart.
Consideration of a proposal by the ICS Subcommission on
Quaternary Stratigraphy and possibly then by the entire ICS will
involve extensive discussion among voting members. Such discus-
sions educate the voting members as they study the proposal, and
such discussion can and should be open to those who are not
voting members. Indeed, this was the nature of the discussion in
2008–2009 that preceded the ICS vote on definition of the
Quaternary System and redefinition of the Pleistocene series. It is
hoped that the audience of this article becomes interested and
contributes to the discussion. All opinions are welcome, but all
positions and arguments are subject to challenge. It is in this
manner that the ICS will give careful consideration to a formal
proposal when submitted.
ACKNOWLEDGMENTS
Brian Pratt and Phillip Gibbard provided reviews of the
submitted manuscript. Earlier drafts were reviewed by Phillip
Gibbard, Martin Head, and Mike Walker. We appreciate their
thorough reviews and valuable suggestions. This article has been
peer reviewed and approved for publication consistent with USGS
Fundamental Science Practices (http://pubs.usgs.gov/circ/1367/).
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