Linear or Cyclical?

Nature has no concept of ‘waste’. By generating toxins and waste that cannot be absorbed through natural processes, humanity has changed the rules and stepped outside the system.

One of the defining features of the progressive design concepts highlighted in this book - from ZERI and Cradle to Cradle to the industrial ecology developed at Kalundborg – is the recognition that waste = food. By treating all waste as a raw material for another industrial process, the concept of ‘zero waste’ becomes a reality.

The sewage system that developed during the industrial age is a classic example of the linear systems that have typified the era, in which waste was directed ‘out of sight and out of mind’, contaminating water sources and then carried out to sea rather than returning important nutrients to the soil.

In the 1840s, the German scientist Justus Liebig tried to persuade the London authorities to build a sewage recycling system for the city, having studied the impact of the linear system in ancient Rome, which had removed the nutrients from their agricultural base in north Africa, then flushed it all into the Mediterranean.

Unfortunately, the linear sewage system that was adopted, mixing waste with water and diverting it into the Thames, was replicated all over the world, thus insuring the gradual loss of soil fertility which a cyclical system would have preserved. Ironically, when London adopted a linear system, Liebig and others set to work on developing artificial fertilisers to replenish the soil, creating the foundations of the modern agro-chemical industry.