MacKenzie, D. April 2, 2008. Why the demise of civilisation may be inevitable. NewScientist.

Every civilization in history has collapsed. Why should ours be any different?

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.

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 industrialized civilization 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.

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.

Environmental mismanagement

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 civilization 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.

Others think our problems run deeper. From the moment our ancestors started to settle down and “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 Societies.

If crops fail because rain is patchy, build irrigation canals. When they silt up, organize 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 organization imposes a cost in terms of energy, the common currency of all human efforts, from building canals to educating scribes. And increasing complexity, Tainter realized, produces diminishing returns. The extra food produced by each extra hour of labor – 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 civilizations, from the early Chinese dynasties to the Greek city state of Mycenae. These civilizations 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 civilization 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.

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 organizations become steadily more complex as they are required to deal both with environmental problems and with challenges from neighboring societies that are also becoming more complex, Bar-Yam says. This eventually leads to a fundamental shift in the way the society is organized.

“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.

Increasing connectedness

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 destabilizing 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 civilization 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 civilization is very vulnerable.”

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 one.

Globalization 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 maximize profits. Some products are produced by only one factory worldwide. Financially, it makes sense, as mass production maximizes efficiency. Unfortunately, it also minimizes 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.”