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Eos, Vol. 94, No. 40, 1 October 2013
AGU BOOKSHELF
Climates, Landscapes, and Civilizations
PAGES 355–356
Humans are now the dominant driver of global climate change. From ocean acidification to
sea level rise, changes in precipitation patterns, and rising temperatures, global warming
is presenting us with an uncertain future. However, this is not the first time human civilizations have faced a changing world. In the AGU monograph Climates, Landscapes, and
Civilizations, editors Liviu Giosan, Dorian Q. Fuller, Kathleen Nicoll, Rowan K. Flad, and
Peter C. Clift explore how some ancient peoples weathered the shifting storms while some
faded away. In this interview, Eos speaks with Liviu Giosan about the decay of civilizations,
ancient adaptation, and the surprisingly long history of humanity’s effect on the Earth.
really matters is how this changes our view of
the Earth. Are climatic phenomena, landscape processes, or various environments
that we see today truly analogues of the past,
or are we already dealing in a large degree
with a series of human constructs?
Eos: A prevalent, though contentious, idea
is that of environmental determinism, which
says that a society’s development is dictated by
its local climate and ecosystem. How much
was an ancient civilization the product of its
environment, and how much control did they
have over it?
Giosan: I grew up under a Communist
regime before coming to the United States,
and I am not a big fan of “-isms.” I am very
sensitive to that. For people coming from natural science who say “everything is climate,”
or the social scientist who says “everything is
people,” we have to find the middle ground
and move beyond the ideological and the
NASA/MODIS Rapid Response Team
Eos: From listening to the modern environmental movement or public discussions around
climate change, it feels as if humans being an
important driver of the global environment is a
relatively recent development. Is that a fair
assessment?
Giosan: I really don’t think there is a clearcut answer—we are just now starting to realize that people might have had a global effect
earlier, much earlier, than we thought. One
example of this is Bill Ruddiman’s “early
anthropocene” hypothesis, which he expands
on in the book. Ruddiman, a paleoclimatologist at the University of Virginia, and his colleagues say that deforestation and changes in
agricultural patterns—basically the agricultural revolution—led to an increase in greenhouse gases. If he’s right, greenhouse gases
have been changed for thousands of years by
human activity. This is a controversial idea,
but it’s not the only example. We know that
between 2000 and 1000 years ago, people
became the biggest global player in redistributing sediment. One millennium ago, people
were moving more dirt around than rivers,
glaciers, and wind combined.
Also, as societies in the pre-industrial past,
we were not very efficient in our agriculture.
We needed more land to feed the same number of people then than now because we
didn’t have fertilizer, we didn’t have the techniques that we have now—we didn’t have the
Green Revolution. So, in much of the western
world, deforestation was actually at its peak
1000 to 500 years ago.
That being said, I think “the world” was
defined very differently for ancient civilizations. The world, if we look at the ancient
Greeks, ended in the Mediterranean. For the
Egyptians, it was largely around the Nile. If
we look at their definition and adopt their
point of view, their world was as affected as
ours by what they did. But our “world” is
the entire planet—where to go next if we
ruin it?
So the question you’re asking is “Did the
anthropocene start with the Agricultural
Revolution or the Industrial Revolution?” In
my opinion, though, I think this is the wrong
question. From a pragmatic point of view, it
doesn’t matter so much when it started. What
political arguments. This book, the conference on which it’s based, and other papers
from that conference published independently are an attempt to bring people together
to move past that stumbling block.
Actually answering your question, though,
is very hard. It’s very hard to know how
much a civilization affected its environment
because we have so little information. We
know very little about most of these civilizations because very few sites have been excavated, even in Egypt, even in Mesopotamia.
So I think the Earth sciences can provide a
framework, but to tackle the question of
people versus environment, which changed
which—that needs input from archaeology
and anthropology. And we’re still far from
that.
Eos: What are some civilizations for which
climatic shifts have been implicated as a driving force behind their demise?
Giosan: Saying that a civilization collapsed
because of climate change is incredibly controversial, because it depends on how you
define collapse. I mean, how do you define
civilization? It’s very charged politically,
“civilization.” If you don’t know how to define
civilization, it’s very hard to define collapse.
Take, for example, the collapse of the Indus
Valley civilization around 4000 years ago.
This “collapse” is marked by the disappearance of written signs that may or may not be
part of a script, the deterioration of built
cities, the disappearance of waterworks, of
large-scale agriculture. The regression of art.
But people still lived there, and they still did
agriculture. Is this a collapse? Earth scientists
tend to see it as a collapse, but social scientists are divided, and they are divided
ideologically.
Much as the widespread flooding (shown (left) before and (right) after the floods) in 2010 devastated people in Pakistan, the behavior of the Indus River would have affected the civilizations
that flourished along its banks thousands of years ago.
© 2013. American Geophysical Union. All Rights Reserved.
Eos, Vol. 94, No. 40, 1 October 2013
There’s a good example in the book on the
Maya civilization. Some city- states decayed
while some flourished during the same time
period. And that’s very human, yeah? Maybe
those that thrived were oriented, for example,
toward trade. Or they had a resource that the
others needed, and in times of crisis, they
gained more wealth than before—they
became richer than the others. So it’s intracivilizational dynamics, it’s also intercivilizational dynamics, that one could go up and
the other down.
If you define a civilization based on some
idea of progress, of something being superior
versus inferior, that’s charged politically. But
if you define it in terms of material things, or
cultural or artistic life, you could say that
decay is part of a civilization’s life cycle.
Eos: Do we, though, have any strong examples of past climate change affecting ancient
civilizations? How were they affected?
Giosan: One example again is that of the
Indus Valley civilization. With modern climate change, much of the focus has been on
global temperature. But let’s say that we are
someone who lives in an arid region by a
river. Does it matter if the temperature goes
up by a degree in a hundred years? Probably
not. But it will matter if the river dries out. In
the case of the Indus civilization, and also
almost all ancient civilizations except China,
they developed in dry regions. Egypt, Mesopotamia, Indus—they all lived near a river,
and the river was their lifeline.
What we are slowly understanding is that
the drying that started around 4200 years ago
and lasted about 2 centuries may have actually been beneficial for the Indus at first. As
far as we know, the peak of their civilization
happened during that dry period. How can
you explain that? Well, you cannot explain it
if you think about precipitation, but those
people didn’t live by precipitation. They lived
by the river, and they benefited when it
flooded. So, what does it mean that it was
dry? It means that floods were less dramatic.
Let’s think back 3 years to the natural catastrophe that happened in Pakistan. Hundreds
of thousands of people were stranded because the Indus River flooded. Can you do
agriculture in that kind of world? Maybe not.
Maybe that drying 4200 years ago somehow
tamed the river, and the floods were weaker
and more amenable to agriculture. These
relationships are so complicated, and we are
so at the beginning of understanding them.
That’s why right now is so exciting for the
paleoclimate and archaeological communities, and that’s why I think the book is so
timely.
Eos: Has climate change ever helped? Or is
it always a hindrance?
Giosan: It has helped, and I’ll give you
what may be a surprising example: India. I’m
not talking about the Indus Valley civilizations, I’m talking about the people who lived
more toward the south of the Indian peninsula. India is driven by the monsoon, and
around 4000 years ago, the precipitation
started to decrease. The drought meant that
they couldn’t live a hunter-gatherer life anymore. The drought events pushed them to
adopt agriculture.
And, again, about 2000 years later, the aridity increased even more. In response, they
developed water storage facilities. If you go to
India, you’ll see all these old tanks dotting
the entire subcontinent. They’re often near
temples or villages, and the oldest are about
2000 years old. The aridity brought that community together and led to the adoption of
agriculture and improvements in technology.
The same thing happened in Mesopotamia
and Egypt, too, with aridity driving the adoption of agriculture. This is an often overlooked
aspect of past climate change. The change
in climate led people to come together, to
search for solutions, to be inventive.
Eos: How can archaeology and anthropology help us address modern climate change?
Are there any lessons to be learned from understanding how ancient civilizations coped?
© 2013. American Geophysical Union. All Rights Reserved.
Giosan: Well, the main lesson is that nothing is forever. It should be written in front of
our eyes. It is very hard to compare ourselves
with past civilizations because we are so
much different than everything that was
before. We have an overblown population
because of oil and the Green Revolution. Yet
the stories of past civilizations are good as
parables, if they are not simplistically
understood.
In the book, there is the example of a Caribbean civilization that built against tsunamis
and hurricanes—houses that were easily
destroyed, but that were also easily rebuilt.
Do you see anybody now building these
kinds of shacks by the shore that will not be
missed if a tsunami comes? It’s probably not a
starter proposition. We are so different.
Although, some lessons could be learned:
that we need to build with resilience in mind,
we need to live with resilience in mind.
Eos: So, then, what can the past offer us as
we try to address modern issues?
Giosan: I don’t think we should necessarily
look for solutions in the deep past, but for stories, for parables. Science is not only about
quantifying and finding solutions, it’s also
about looking for insight into human nature.
How did our ancestors deal with similar problems, and what was their response?
Our world, the academic world, is going
more and more into the direction of quantification, which is good, but let’s not forget that
wisdom is not the same as facts. Remembering that is to the benefit not only of us as scientists but also to the public and those who
lead us—everything is easier to understand
with the help of a parable.
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—COLIN SCHULTZ, Writer