Contemplating the demise of civilization is not
for the faint of heart. At least it is fair to
say we live in interesting times.
DOOMSDAY. The end of civilisation. Literature and
film abound with tales of plague, famine and wars
which ravage the planet, leaving a few survivors
scratching out a primitive existence amid the ruins.
Every civilisation in history has collapsed, after
all. Why should ours be any different?
Doomsday scenarios typically feature a knockout blow:
a massive asteroid, all-out nuclear war or a
catastrophic pandemic (see "Will a pandemic bring
down civilisation?"). Yet there is another chilling
possibility: what if the very nature of civilisation
means that ours, like all the others, is destined to
collapse sooner or later?
A few researchers have been making such claims for
years. Disturbingly, recent insights from fields such
as complexity theory suggest that they are right. It
appears that once a society develops beyond a certain
level of complexity it becomes increasingly fragile.
Eventually, it reaches a point at which even a
relatively minor disturbance can bring everything
Some say we have already reached this point, and that
it is time to start thinking about how we might
manage collapse. Others insist it is not yet too
late, and that we can - we must - act now to keep
disaster at bay.
History is not on our side. Think of Sumeria, of
ancient Egypt and of the Maya. In his 2005
best-seller Collapse, Jared Diamond of the University
of California, Los Angeles, blamed environmental
mismanagement for the fall of the Mayan civilisation
and others, and warned that we might be heading the
same way unless we choose to stop destroying our
environmental support systems.
Lester Brown of the Earth Policy Institute in
Washington DC agrees. He has long argued that
governments must pay more attention to vital
environmental resources. "It's not about saving the
planet. It's about saving civilisation," he says.
Others think our problems run deeper. From the moment
our ancestors started to settle down and build
cities, we have had to find solutions to the problems
that success brings. "For the past 10,000 years,
problem solving has produced increasing complexity in
human societies," says Joseph Tainter, an
archaeologist at Utah State University, Logan, and
author of the 1988 book The Collapse of Complex
If crops fail because rain is patchy, build
irrigation canals. When they silt up, organise
dredging crews. When the bigger crop yields lead to a
bigger population, build more canals. When there are
too many for ad hoc repairs, install a management
bureaucracy, and tax people to pay for it. When they
complain, invent tax inspectors and a system to
record the sums paid. That much the Sumerians knew.
There is, however, a price to be paid. Every extra
layer of organisation imposes a cost in terms of
energy, the common currency of all human efforts,
from building canals to educating scribes. And
increasing complexity, Tainter realised, produces
diminishing returns. The extra food produced by each
extra hour of labour - or joule of energy invested
per farmed hectare - diminishes as that investment
mounts. We see the same thing today in a declining
number of patents per dollar invested in research as
that research investment mounts. This law of
diminishing returns appears everywhere, Tainter says.
To keep growing, societies must keep solving problems
as they arise. Yet each problem solved means more
complexity. Success generates a larger population,
more kinds of specialists, more resources to manage,
more information to juggle - and, ultimately, less
bang for your buck.
Eventually, says Tainter, the point is reached when
all the energy and resources available to a society
are required just to maintain its existing level of
complexity. Then when the climate changes or
barbarians invade, overstretched institutions break
down and civil order collapses. What emerges is a
less complex society, which is organised on a smaller
scale or has been taken over by another group.
Tainter sees diminishing returns as the underlying
reason for the collapse of all ancient civilisations,
from the early Chinese dynasties to the Greek city
state of Mycenae. These civilisations relied on the
solar energy that could be harvested from food,
fodder and wood, and from wind. When this had been
stretched to its limit, things fell apart.
An ineluctable process
Western industrial civilisation has become bigger and
more complex than any before it by exploiting new
sources of energy, notably coal and oil, but these
are limited. There are increasing signs of
diminishing returns: the energy required to get each
new joule of oil is mounting and although global food
production is still increasing, constant innovation
is needed to cope with environmental degradation and
evolving pests and diseases - the yield boosts per
unit of investment in innovation are shrinking.
"Since problems are inevitable," Tainter warns, "this
process is in part ineluctable."
Is Tainter right? An analysis of complex systems has
led Yaneer Bar-Yam, head of the New England Complex
Systems Institute in Cambridge, Massachusetts, to the
same conclusion that Tainter reached from studying
history. Social organisations become steadily more
complex as they are required to deal both with
environmental problems and with challenges from
neighbouring societies that are also becoming more
complex, Bar-Yam says. This eventually leads to a
fundamental shift in the way the society is
"To run a hierarchy, managers cannot be less complex
than the system they are managing," Bar-Yam says. As
complexity increases, societies add ever more layers
of management but, ultimately in a hierarchy, one
individual has to try and get their head around the
whole thing, and this starts to become impossible. At
that point, hierarchies give way to networks in which
decision-making is distributed. We are at this point.
This shift to decentralised networks has led to a
widespread belief that modern society is more
resilient than the old hierarchical systems. "I don't
foresee a collapse in society because of increased
complexity," says futurologist and industry
consultant Ray Hammond. "Our strength is in our
highly distributed decision making." This, he says,
makes modern western societies more resilient than
those like the old Soviet Union, in which decision
making was centralised.
Things are not that simple, says Thomas Homer-Dixon,
a political scientist at the University of Toronto,
Canada, and author of the 2006 book The Upside of
Down. "Initially, increasing connectedness and
diversity helps: if one village has a crop failure,
it can get food from another village that didn't."
As connections increase, though, networked systems
become increasingly tightly coupled. This means the
impacts of failures can propagate: the more closely
those two villages come to depend on each other, the
more both will suffer if either has a problem.
"Complexity leads to higher vulnerability in some
ways," says Bar-Yam. "This is not widely understood."
The reason is that as networks become ever tighter,
they start to transmit shocks rather than absorb
them. "The intricate networks that tightly connect us
together - and move people, materials, information,
money and energy - amplify and transmit any shock,"
says Homer-Dixon. "A financial crisis, a terrorist
attack or a disease outbreak has almost instant
destabilising effects, from one side of the world to
For instance, in 2003 large areas of North America
and Europe suffered blackouts when apparently
insignificant nodes of their respective electricity
grids failed. And this year China suffered a similar
blackout after heavy snow hit power lines. Tightly
coupled networks like these create the potential for
propagating failure across many critical industries,
says Charles Perrow of Yale University, a leading
authority on industrial accidents and disasters.
Perrow says interconnectedness in the global
production system has now reached the point where "a
breakdown anywhere increasingly means a breakdown
everywhere". This is especially true of the world's
financial systems, where the coupling is very tight.
"Now we have a debt crisis with the biggest player,
the US. The consequences could be enormous."
"A networked society behaves like a multicellular
organism," says Bar-Yam, "random damage is like
lopping a chunk off a sheep." Whether or not the
sheep survives depends on which chunk is lost. And
while we are pretty sure which chunks a sheep needs,
it isn't clear - it may not even be predictable -
which chunks of our densely networked civilisation
are critical, until it's too late.
"When we do the analysis, almost any part is critical
if you lose enough of it," says Bar-Yam. "Now that we
can ask questions of such systems in more
sophisticated ways, we are discovering that they can
be very vulnerable. That means civilisation is very
So what can we do? "The key issue is really whether
we respond successfully in the face of the new
vulnerabilities we have," Bar-Yam says. That means
making sure our "global sheep" does not get injured
in the first place - something that may be hard to
guarantee as the climate shifts and the world's fuel
and mineral resources dwindle.
Tightly coupled system
Scientists in other fields are also warning that
complex systems are prone to collapse. Similar ideas
have emerged from the study of natural cycles in
ecosystems, based on the work of ecologist Buzz
Holling, now at the University of Florida,
Gainesville. Some ecosystems become steadily more
complex over time: as a patch of new forest grows and
matures, specialist species may replace more
generalist species, biomass builds up and the trees,
beetles and bacteria form an increasingly rigid and
ever more tightly coupled system.
"It becomes an extremely efficient system for
remaining constant in the face of the normal range of
conditions," says Homer-Dixon. But unusual conditions
- an insect outbreak, fire or drought - can trigger
dramatic changes as the impact cascades through the
system. The end result may be the collapse of the old
ecosystem and its replacement by a newer, simpler
Globalisation is resulting in the same tight coupling
and fine-tuning of our systems to a narrow range of
conditions, he says. Redundancy is being
systematically eliminated as companies maximise
profits. Some products are produced by only one
factory worldwide. Financially, it makes sense, as
mass production maximises efficiency. Unfortunately,
it also minimises resilience. "We need to be more
selective about increasing the connectivity and speed
of our critical systems," says Homer-Dixon.
"Sometimes the costs outweigh the benefits."
Is there an alternative? Could we heed these warnings
and start carefully climbing back down the complexity
ladder? Tainter knows of only one civilisation that
managed to decline but not fall. "After the Byzantine
empire lost most of its territory to the Arabs, they
simplified their entire society. Cities mostly
disappeared, literacy and numeracy declined, their
economy became less monetised, and they switched from
professional army to peasant militia."
Staving off collapse
Pulling off the same trick will be harder for our
more advanced society. Nevertheless, Homer-Dixon
thinks we should be taking action now. "First, we
need to encourage distributed and decentralised
production of vital goods like energy and food," he
says. "Second, we need to remember that slack isn't
always waste. A manufacturing company with a large
inventory may lose some money on warehousing, but it
can keep running even if its suppliers are
temporarily out of action."
The electricity industry in the US has already
started identifying hubs in the grid with no
redundancy available and is putting some back in,
Homer-Dixon points out. Governments could encourage
other sectors to follow suit. The trouble is that in
a world of fierce competition, private companies will
always increase efficiency unless governments
subsidise inefficiency in the public interest.
Homer-Dixon doubts we can stave off collapse
completely. He points to what he calls "tectonic"
stresses that will shove our rigid, tightly coupled
system outside the range of conditions it is becoming
ever more finely tuned to. These include population
growth, the growing divide between the world's rich
and poor, financial instability, weapons
proliferation, disappearing forests and fisheries,
and climate change. In imposing new complex solutions
we will run into the problem of diminishing returns -
just as we are running out of cheap and plentiful
"This is the fundamental challenge humankind faces.
We need to allow for the healthy breakdown in natural
function in our societies in a way that doesn't
produce catastrophic collapse, but instead leads to
healthy renewal," Homer-Dixon says. This is what
happens in forests, which are a patchy mix of old
growth and newer areas created by disease or fire. If
the ecosystem in one patch collapses, it is
recolonised and renewed by younger forest elsewhere.
We must allow partial breakdown here and there,
followed by renewal, he says, rather than trying so
hard to avert breakdown by increasing complexity that
any resulting crisis is actually worse.
Lester Brown thinks we are fast running out of time.
"The world can no longer afford to waste a day. We
need a Great Mobilisation, as we had in wartime," he
says. "There has been tremendous progress in just the
past few years. For the first time, I am starting to
see how an alternative economy might emerge. But it's
now a race between tipping points - which will come
first, a switch to sustainable technology, or
Tainter is not convinced that even new technology
will save civilisation in the long run. "I sometimes
think of this as a 'faith-based' approach to the
future," he says. Even a society reinvigorated by
cheap new energy sources will eventually face the
problem of diminishing returns once more. Innovation
itself might be subject to diminishing returns, or
perhaps absolute limits.
Studies of the way cities grow by Luis Bettencourt of
the Los Alamos National Laboratory, New Mexico,
support this idea. His team's work suggests that an
ever-faster rate of innovation is required to keep
cities growing and prevent stagnation or collapse,
and in the long run this cannot be sustainable.
The stakes are high. Historically, collapse always
led to a fall in population. "Today's population
levels depend on fossil fuels and industrial
agriculture," says Tainter. "Take those away and
there would be a reduction in the Earth's population
that is too gruesome to think about."
If industrialised civilisation does fall, the urban
masses - half the world's population - will be most
vulnerable. Much of our hard-won knowledge could be
lost, too. "The people with the least to lose are
subsistence farmers," Bar-Yam observes, and for some
who survive, conditions might actually improve.
Perhaps the meek really will inherit the Earth.
Read the companion article about pandemics
Could a pandemic bring down
05 April 2008: From issue 2650 of New Scientist
magazine, 02 April 2008, page 32-35