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LESSONS FROM THE PAST
Chapter 1. The Economy and the Earth
Lester R. Brown, Eco-Economy: Building an Economy for the Earth
(W.W. Norton & Co., NY: 2001).
In The Collapse of Complex Civilizations,
Joseph Tainter describes the decline of early civilizations and
speculates about the causes. Was it because of the degradation of
their environment, climate change, civil conflict, foreign invaders?
Or, he asks, "is there some mysterious internal dynamic to the rise
and fall of civilizations?"33
As he ponders the contrast between civilizations that once flourished
and the desolation of the sites they occupied, he quotes archeologist
Robert McC. Adams, who described the site of the ancient Sumerian
civilization located on the central floodplain of the Euphrates
River, an empty, desolate area now outside the frontiers of cultivation.
Adams described how the "tangled dunes, long disused canal levees,
and the rubble-strewn mounds of former settlement contribute only
low, featureless relief. Vegetation is sparse, and in many areas
it is almost wholly absent..Yet at one time, here lay the core,
the heartland, the oldest urban, literate civilization in the world."34
The early Sumerian civilization of the fourth millennium BC was
remarkable, advancing far beyond any that had existed before. Its
irrigation system, based on sophisticated engineering concepts,
created a highly productive agriculture, one that enabled farmers
to produce a surplus of food that supported the formation of the
first cities. Managing the irrigation system required a complex
social organization, one that may have been more sophisticated than
any that had gone before. The Sumerians had the first cities and
the first written language, the cuneiform script. They were probably
as excited about it as we are today about the Internet.35
It was an extraordinary civilization, but there was an environmental
flaw in the design of the irrigation system, one that would eventually
undermine its agricultural economy. Water from behind dams was diverted
onto the land, raising crop yields. Some of the water was used by
the crops, some evaporated into the atmosphere, and some percolated
downward. Over time, this percolation slowly raised the water table
until eventually it approached the surface of the land. When it
reached a few feet from the surface it began to restrict the growth
of deep-rooted crops. Somewhat later, as the water climbed to within
inches of the surface, it began to evaporate into the atmosphere.
As this happened, the salt in the water was left behind. Over time,
the accumulation of salt reduced the productivity of the land. The
environmental flaw was that there was no provision for draining
the water that percolated downward.36
The initial response of the Sumerians to declining wheat yields
was to shift to barley, a more salt-tolerant plant. But eventually
the yields of barley also declined. The resultant shrinkage of the
food supply undermined the economic foundation of this great civilization.37
The New World counterpart to Sumer is the Mayan civilization that
developed in the lowlands of what is now Guatemala. It flourished
from AD 250 until its collapse around AD 900. Like the Sumerians,
the Mayans had developed a sophisticated, highly productive agriculture,
one that relied on raised plots of earth surrounded by canals that
supplied water.38
As with Sumer, the Mayan demise was apparently linked to a failing
food supply. For this New World civilization, it was deforestation
and soil erosion that undermined agriculture. Food scarcity may
then have triggered civil conflict among the various Mayan cities
as they competed for food.39
During the later centuries of the Mayan civilization, a new society
was evolving on Easter Island, some 166 square kilometers of land
in the South Pacific roughly 3,200 kilometers west of South America
and 2,200 kilometers from Pitcairn Island, the nearest habitation.
Settled around AD 400, this civilization flourished on a volcanic
island with rich soils and lush vegetation, including trees that
grew 25 meters tall with trunks 2 meters in diameter. Archeological
records indicate that the islanders ate mainly seafood, principally
dolphins-a mammal that could only be caught by harpoon from large
sea-going canoes since it was not locally available in large numbers.40
The Easter Island society flourished for several centuries, reaching
an estimated population of 20,000. As its human numbers gradually
increased, tree cutting exceeded the sustainable yield of forests.
Eventually the large trees needed to build the sturdy, ocean-going
canoes disappeared, depriving islanders of access to the dolphins,
thus dramatically shrinking the island's seafood supply. The archeological
record shows that at some point human bones became intermingled
with the dolphin bones, suggesting a desperate society that had
resorted to cannibalism. Today the island is occupied by some 2,000
people.41
These are just three of the early civilizations that declined apparently
because at some point they moved onto an economic path that was
environmentally unsustainable. We, too, are on such a path. Any
one of several trends of environmental degradation could undermine
civilization as we know it. Just as the irrigation system that defined
the early Sumerian economy had a flaw, so too does the fossil fuel
energy system that defines our modern economy. It is raising CO2
levels in the atmosphere and thus altering the earth's climate.
Whether it was from the salting of the land in Sumer, the soil erosion
of the Mayans, or the loss of the distant-water fishing capacity
of the Easter Islanders, collapse of the early civilizations appears
to have been associated with a decline in food supply. Today the
addition of 80 million people a year to world population at a time
when water tables are falling suggests that food supplies again
may be the vulnerable link between the environment and the economy.42
The Sumerians did not know that the New World even existed, much
less that it would one day support flourishing civilizations, such
as the Mayans. The Mayans had no idea that Easter Island existed.
Each of these civilizations collapsed in isolation, with no effect
on the others. But today, in an integrated global economy, a collapse
in one country or region will affect all of us. Even a currency
devaluation in a developing country, such as Indonesia, can send
shock waves through Wall Street half a world away.
One unanswerable question about these earlier civilizations was
whether they knew what was causing their decline. Did the Sumerians
understand that rising salt content in the soil was reducing their
wheat yields? If they knew, were they simply unable to muster the
political support needed to lower water tables, just as we today
are struggling unsuccessfully to lower carbon emissions?
ENDNOTES:
33. Joseph Tainter, The Collapse of Complex Civilizations (Cambridge:
Cambridge University Press, 1988), p. 1.
34. Ibid.
35. Postel, op. cit note 3, pp. 13-21.
36. Ibid.
37. Ibid.
38. "Maya," Encyclopaedia Britannica, online encyclopedia, viewed
7 August 2000.
39. Ibid.
40. Jared Diamond, "Easter's End," Discover, August 1995, pp. 63-69.
41. Ibid.
42. Population addition from United Nations, op. cit. note 25.
Copyright
© 2001 Earth Policy Institute
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