There's an interesting article by Debora MacKenzie in the April 2 edition of New Scientist about what happens to civilisations when they reached a certain 'critical mass'.

She argues this chilling possibility: what if the very nature of civilisation means that ours, like all the others, is
destined to collapse sooner or later?

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 istime 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.

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 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 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. 

Roll on is what I reckon. We are fiddling around with strategies, Green Papers, massive Landcare networks which all suck up huge amounts of money - and what do we get? More of the same!