http://www.newscientist.com/channel/being-human/mg19826501.500-the-demise-of-civilisation-may-be-inevitable.html
The demise of civilisation may be inevitable
02 April 2008 Debora MacKenzie newscientist Magazine issue 2650
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 "The end of 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 crashing down.
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 the University of Utah, Salt Lake City, and author of the 1988 book The Collapse
of Complex Societies.
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.
Diminishing returns
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.
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 organised.
"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 the other."
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.
Credit crunch
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."
"The networks that connect us can amplify any shocks. A breakdown anywhere increasingly means a
breakdown everywhere"
"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 vulnerable."
"We are discovering that networked systems can be very vulnerable. That means civilisation is very
vulnerable"
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.
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 one.
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."
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 energy.
"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 collapse?"
"It's now a race between tipping points - which will come first, a switch to sustainable technology
or collapse?"
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.
___________________________________
Støtte lige på denne artikel, som jeg mener viser et eksempel
på "Diminishing returns", ved at finde på en teknisk løsning, som
beskrevet i ovenstående artikel.
http://www.terradaily.com/2007/080404164356.uye3mgkp.html
Drought-hit Barcelona to import water by boat from France
BARCELONA, Spain, April 4 (AFP) Apr 04, 2008
Boats will from next month bring fresh water from other parts of Spain and neighbouring France to
Barcelona to help the city deal with the region's worst drought in decades, local government
officials said Friday.
The boats will supply Spain's second-largest city with enough water to meet Barcelona's consumption
needs for five days -- at a cost of 22 million euros (34.4 million dollars).
The first ship will depart from the Spanish Mediterranean city of Tarragona for Barcelona during the
first two weeks of May, said a spokesman for the environment ministry of the regional government of
Catalonia.
Two more ships loaded with water will leave the French port city of Marseille for the Catalan
capital during the second half of the month, the spokesman added.
Water reserves across Spain have dropped to 46.6 percent of capacity, a 20 percentage point drop
over the level recorded a decade ago.
The situation is especially critical in the northeastern region of Catalonia, whose capital is
Barcelona, where water reserves at just 19 percent of capacity.
If they drop below 15 percent, the water from the dams cannot be used as it is too close to the
bottom and will have too much sediment.
To cope with the drought, the Catalan government wanted to divert water from the river Segre, a
tributary of the gigantic Ebro, to Barcelona but this plan was rejected by the central Spanish
government in Madrid which argued it was bad for the environment.
The Catalan government had also planned to import fresh water by train from other regions of Spain
but this was ultimately discarded as too expensive.
Jan Rasmussen