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1History and Development of
the Anthropocene as a
Stratigraphic Concept
CONTENTS
1.1 A General Introduction to the Anthropocene 2
Jan Zalasiewicz, Colin N. Waters, Mark Williams, Colin P. Summerhayes, Martin J. Head and
Reinhold Leinfelder
1.2 History of the Anthropocene Concept 4
Jacques Grinevald, John McNeill, Naomi Oreskes, Will Steffen, Colin P. Summerhayes and
Jan Zalasiewicz
1.3 Stratigraphy and the Geological Time Scale 11
Jan Zalasiewicz, Colin P. Summerhayes, Martin J. Head, Scott Wing, Phil Gibbard and
Colin N. Waters
1.4 The Utility of Formalisation of the Anthropocene for Science 31
Davor Vidas, Jan Zalasiewicz, Will Steffen, Trevor Hancock, Anthony Barnosky, Colin P.
Summerhayes and Colin N. Waters
We introduce here the concept of the Anthropocene as a potential geological unit of time, while
noting that antecedents of this concept were sporadically present in previous literature prior to its
effective inception, by Paul Crutzen, in 2000 CE. We describe how the Anthropocene compares
with examples from the Geological Time Scale throughout Earth history, and demonstrate the
extent to which the term has practical utility in the field of geology, in the field of natural science
generally, and to the wider academic community. In this book we describe the geological
Anthropocene, while this definition does not exclude other, different, interpretations of the
Anthropocene that have appeared in recent years amongst other scholarly communities,
particularly in the humanities. We explain here how this book will help to inform the process of
producing a formal proposal for the Anthropocene as a geological time unit. Examples from the
beginning of the Cenozoic Era, the Cambrian, Silurian and Quaternary periods, and the Eocene
and Holocene epochs are used to demonstrate how chronostratigraphic boundaries are defined
and what lessons from these can be applied to defining the Anthropocene.
via www.cambridge.org/9781108475235
1.1 A General Introduction to
the Anthropocene
Jan Zalasiewicz, Colin N. Waters, Mark
Williams, Colin P. Summerhayes, Martin J. Head
and Reinhold Leinfelder
The Anthropocene, launched as a concept by Paul
Crutzen in 2000 (Crutzen & Stoermer 2000; Crutzen
2002), has in less than two decades grown astonishingly
in its range and reach amongst different academic
communities. Fundamentally, it was coined to crystallise
the growing realisation that human activities –or,
more often, the unintended consequences of human
activities –had fundamentally changed the Earth
System. Hence, the patterns of behaviour of the oceans,
atmosphere, land (i.e., the geosphere’sterrestrial surface),
cryosphere, biosphere and climate are no longer those
that over 11 millennia characterised the great bulk of the
epoch that we still formally live in, the Holocene. The
accent on planetary processes reflected the character of
the scientific community that Paul Crutzen was working
in, that of the Earth System science (ESS) community,
concerned most acutely with contemporary global
change.
Nevertheless, the Anthropocene was explicitly
described as a geological time interval, as an epoch
in direct comparison to –and different from –
the Holocene because of the inferred geological
significance of the altered Earth System processes.
The implicit hypothesis was that the Holocene had
terminated, perhaps about when the Industrial
Revolution started. This improvised proposal
chimed with the conclusions on the nature, scale
and speed of global change being reached by the
ESS community, and the term soon began to be
widely used in publications, matter-of-factly, as if
it were already part of accepted geological time
terminology. It was not formal, though, having
gone through none of the extensive formal
analysis, debate, agreement (via an established
pattern of voting amongst appropriate stratigraphic
bodies) and ratification that formal geological time
terms require (and which are described fully in
Section 7.8.1).
A few years after Crutzen’s intervention, increasing
use of the term began to be noticed by the geological
community, and a preliminary analysis by a
national body, the Stratigraphy Commission of the
Geological Society of London, suggested that the term
had merit and should be studied further with respect
to any potential formalisation. This conclusion was
in sharp contrast to the general response by the
geological community to sporadic earlier suggestions
of a ‘human era’, which had indeed been made since
the late 18th century (Stoppani 1873; Buffon 2018).
These suggestions had always been generally rejected,
on the basis that the great forces of nature that drove
Earth’s geology were considered to operate on a vaster
and longer-term scale than any kind of human impact,
which by comparison was widely considered ‘too
puny’. The realisation, even amongst geologists, that
humans could indeed significantly affect not only the
Earth System parameters but, as a consequence of
this, also the course of Earth’s geological evolution,
led to an invitation from the Subcommission of
Quaternary Stratigraphy (SQS) of the International
Commission on Stratigraphy (ICS) to set up a formal
Anthropocene Working Group (AWG); to examine
the case for formalisation; and ultimately to make
recommendations to the SQS, ICS and the latter’s
parent body, the International Union of Geological
Sciences (IUGS).
This book is the outcome of the work of the
Anthropocene Working Group since 2009 in
developing and testing the general case for the
Anthropocene as a formal geological time unit. This
work was a necessary prelude to preparing any specific
formalisation proposal to the SQS, ICS and IUGS (a task
that is underway). It summarises the evidence gathered
in the intervening time, both by AWG members and
others, for what we may here call the ‘geological
Anthropocene’or perhaps ‘stratigraphic
Anthropocene’. This distinguishes it from other
interpretations of the Anthropocene that have emerged
in these last few years as a range of communities,
21.1 A General Introduction to the Anthropocene
including those within the social sciences, humanities
and arts, have explored this term and concept through
the prisms of their own disciplines.
Thus, in our discussions of the Anthropocene to
follow, there are a few things to bear in mind. Firstly,
its interpretation here is non-exclusive –it does not in
any way restrict (or seek to restrict) the potential use
of the word in other meanings, by other communities,
as has indeed been the case in the last decade (e.g.,
Edgeworth et al. 2015; Ruddiman et al. 2015a). Many
words have more than one meaning –the word
‘mantle’, for instance, can be applied to part of the
Earth beneath the crust, to an item of clothing, to a
type of tissue on a mollusc or to part of an old-
fashioned gas lamp. Sometimes the meaning of the
word is clear from the context, and sometimes an
appropriate qualifier needs to be used to ensure
precision of communication; we suggest that such
care in communication now needs to apply to the
term ‘Anthropocene’too.
We recognise that accepting the various material
signals of the geological Anthropocene as a valid
scientific outcome of stratigraphic analysis may lead,
as a corollary, to analysis of the societal, cultural and
political causes and consequences of the existence of
a geological Anthropocene. Such a broader level of
analysis is potentially of considerable importance and
would involve extensive cooperation of the sciences,
the humanities, the arts and society. However, it goes
beyond the mandate of the Anthropocene Working
Group and the scope of this book. One might use a
medical metaphor, in that the characterisation and
definition of a geological Anthropocene may be said
to be diagnosing the condition of a planet through a
particular set of symptoms, against the background of
a very long family history. Such analysis of the
geological Anthropocene does not, though,
investigate the causes of the condition too deeply, nor
does it offer any treatment plan or much in the way of
a prognosis.
In a geological context, the Anthropocene is here
considered as a unit of Earth history and, more than
this, as a potentially formal unit that might become part
of the ICS-produced International Chronostratigraphic
Chart (which informs the Geological Time Scale). It
would thus comprise a potential Anthropocene Epoch
and, as its essential material counterpart and alter ego,
simultaneously an Anthropocene Series, which is a unit
of strata that can be dug into, sampled and –in a few
cases, despite its geological youth –hit with a hammer.
The value of such a designation is to make the most
effective comparison between present processes and
those of the deep geological past: to, as far as possible,
compare like with like in making such comparisons. As
the history of the Earth prior to human documentation
can only be inferred from the rock record, this focus on
material, stratal evidence is critical to comparing the
modern and ancient histories of this planet and
therefore to gauging the relative scale and rate of
human-driven perturbation. The geological
Anthropocene, therefore, has to be considered within
the established rules and guidelines that apply to all
other units of the Geological Time Scale. For instance, it
is important that, as far as possible, its beginning (and
its base, when applied to strata) is synchronous around
the world (see Section 7.8).
The geological Anthropocene is not a diachronous
unit of human cultural history like the Iron Age and
Palaeolithic, which unfolded in mosaic fashion across
the planet, or like the Renaissance (though other
social science interpretations of the Anthropocene
may approximate to such units). More generally,
descriptions of it as a ‘human epoch’are in some
respects misleading. The Anthropocene is here
considered as an epoch of Earth time, just like all
Earth’s previous epochs. It so happens that its
distinctive characteristics have up until now been
driven largely by a variety of human actions. But if
these characteristics (such as sharply increased
atmospheric carbon dioxide levels, global carbon
isotope and nitrogen isotope anomalies, a biosphere
modified by species extinctions and invasions, and so
on –Figure 1.1.1) were driven by any other means –
such as by a meteorite impact, volcanic eruptions or
the actions of another species –then they would have
exactly the same importance geologically.
History and Development of the Anthropocene as a Stratigraphic Concept 3
Therefore, setting out these preliminary constraints of
what we consider the stratigraphic Anthropocene to be
and also not to be (constraints that are placed upon all of
the units of the Geological Time Scale) helps explain the
particular content and emphases that we place in this
book. The Anthropocene represents a remarkable episode
in the history of the Earth, a narrative that is unfinished
but that has emphatically begun, and one that is of no
little consequence for present and future communities.
Examining it in classical geological terms will, we hope,
be useful to geologists and non-geologists alike.
1.2 History of the Anthropocene Concept
Jacques Grinevald, John McNeill, Naomi
Oreskes, Will Steffen, Colin P. Summerhayes and
Jan Zalasiewicz
Is the modern scientific concept of the Anthropocene
an old idea, dating back a century or more yet
retaining its meaning and perspective? Or is it a new,
paradigm-shifting conceptual novelty? This question
is rendered more complicated by the diversity of
Figure 1.1.1 Trends in key stratigraphic indicators from the Late Pleistocene to the present time. Note the largely gradual
change (at this scale) across the Pleistocene-Holocene boundary, the general stability through the Holocene, and the marked
inflections and incoming of novel indicators that clearly demarcate a changed trajectory from the mid-20th century, identified
as the Anthropocene. From Zalasiewicz et al. (2018). (POPs = persistent organic pollutants.)
41.2 History of the Anthropocene Concept
