Populate ... and perish? Policy lessons from the past

The Mayan story tells us a lot about technology 'solutions' and unsustainable cities.

Policy agendas are curious beasts. There are always more ideas running around than most political systems can process, so some "get up" while others are overlooked or ignored. When it comes to implementation, the channelling process can be even more selective.

Take climate change, for example. Scientists have been raising the alarm about it for a long time. I remember when I worked for the Australian Science and Technology Council in the late 1980s, we discussed prognoses that looked very grim indeed.

But we humans have a propensity to look away from really bad or difficult news. And when we do get around to doing something, we like to pin our hopes on simple solutions.

Not so long ago, policymakers talked about tackling climate change on many fronts. Now it seems there is just one: renewables. In the name of renewables, we have created a protective amulet called "green energy". We have subsidised green energy to the point where other ways of dealing with emissions – for example, planting or even just conserving trees – do not receive nearly as much attention as they should.

I am reminded of the Maya, a meso-American people whose civilisation collapsed in the 10th century, largely due to climate change. Of course, what happened to the Maya was not the result of increased carbon dioxide emissions. While highly advanced in many ways, they were a pre-industrial people. But like our own, their society was challenged at its deepest level.


So what happened? It has been established that there was a prolonged drought in both the southern and northern parts of the Mayan world during the 10th century. This dry period followed one of relative abundance, during which populations had increased.

To feed increasing numbers, farmers had moved onto less stable soils, which meant that, when the dry years came, they were unable to provide the surplus on which the elite depended. The Maya were able to store and distribute water but their staple crop, maize, deteriorated in the heat and humidity. In a land of highly variable rainfall, they were not as resilient as they needed to be.

Clearly, the Maya had over-reached themselves, and some adjustment was necessary. Whether we see theirs as a story of collapse, or one of adaptation, depends upon your point of view. Pessimists tend to see collapse; optimists, adaptation. What is more interesting, I think, is to ask: what did the Maya themselves think about what was happening?

While Mayan culture and languages survived centuries of often brutal repression, the ancient sites themselves became the subject of myth, rather than direct memory. So we have to guess. The ruling class, whose position was based upon the closeness of their relationship to the gods, presumably did all they could to hang on to power. There is some evidence of special underground sacrifices being made to the rain god, Chaac, about the time of the great drought. There may also have been increased warfare between the city states, as ruling families sought resources elsewhere. But, over time, the Maya who actually did the work clearly decided that the ruling class, and the panoply of science and religion that surrounded them, were no longer legitimate. So they voted with their feet.

There is a familiar ring to this, isn't there? We may wear the protective amulet of green energy, but we still believe in growth, and the sacrifices that must be made to keep it going. Unlike the Maya, who built stone pyramids, we continue to build crazy pyramids of debt, with periodic sacrifices of the less fortunate to keep the priesthood going. As long as the priests ensure that the goodies keep appearing, we more or less do what they say. But the have-nots are banging at the doors of the citadel and, in many cases, have breached it entirely. Among the haves, many are beginning to notice that there are some who have a great deal more than others.

All the time, the earth's natural systems continue to evolve – underneath, above us and around us. Whatever we think we know, we are, like the Maya, prisoners of our past assumptions. In some ways, the earth seems massive and resilient to us, the oceans endless. On the other hand, it doesn't take much to wreck the ecology of an area. Australia shows examples of it everywhere: eroded creek beds, paddocks infested with serrated tussock, and feral animals in their thousands roaming the landscape. The soils will produce but only with the application of extensive superphosphate, trace elements and irrigation water. Bringing them back to productivity naturally is a slow and expensive business.

Unlike the Maya, who built stone pyramids, we continue to build crazy pyramids of debt, with periodic sacrifices of the less fortunate to keep the priesthood going.

The Mayan story tells us a lot about complexity. It took a while for populations to disperse, and there were different outcomes in different areas. Even when moving out seemed the best option, the Maya, at least, had somewhere to go. Their technologies had not saved them, but they had not destroyed them either. Our technologies are more powerful, and therein lies the problem. Where will we go if the biological systems underpinning our cities fail?

Most of us have no idea where our food comes from, nor do we care. We assume there will always be more than enough, either locally grown or imported. Like the Maya, who destroyed vast areas of tropical forest to make way for their cities, we are driven to assert our control. We house our increasing population in huge boxes called apartments. We tear down trees and build on parks. People live in increasing congestion, and we call it progress.

Imagine our stadiums, airports, hospitals, universities, skyscrapers and churches being visited by curious tourists several centuries hence. What were those people thinking, they might ask? Why did they keep on building monuments when they knew they weren't sustainable? Our cities are the places of our greatest achievements, but they could also be responsible for our greatest vulnerabilities.

Professor Jenny Stewart is a visiting fellow in the school of business at UNSW Canberra.