The preventive strategy seeks to identify the causes of environmental emissions and find ways of reducing these emissions. At one level, we could take the demand for services as the underlying causative element. But as I have already remarked in Chapter 3, we must draw the line somewhere between reducing material throughputs and jeopardising human welfare. Eliminating the demand for services is not a legitimate or viable basis for any environmental management strategy! This does not mean that the demand for services should remain entirely unchallenged. But it is a complex issue, and requires a careful and balanced understanding of where those demands come from. I shall return to this topic at later stages in the book.
For the moment, let us concentrate our attentions on the black box itself. One way of characterising earlier approaches to waste management is to say that they focus all their attention on the material emissions from the given system. They take for granted both the demand for services and the complex technological parameters of the black box itself.
The first point to make about the preventive approach is that it must seek to unravel the hidden complexity of the service system. It is within this system that material input requirements are decided on, and material outputs are determined. To apply the preventive strategy effectively, therefore, we must first look within the system and then be prepared to redesign—and where necessary reconceive—it altogether. So let us now take a closer look at the component parts of the system illustrated in Figure 9.
Figure 10 breaks the service system down into several stages which are more or less sequential. The rectangular boxes in the diagram represent the familiar stages of material transformation within the economy: mining, manufacturing and distribution of material products, and subsequent waste management after use. These stages require resource inputs and they deliver material outputs. The oval stages are essentially non-material in nature, although they are intimately related to the material aspects of the system.
The first and perhaps the most critical of these stages is the one which represents the conceptualisation of the provision of a particular service. It is here that the performance parameters of the system and its material dimensions are ultimately determined. For instance, we can conceive of a system for providing food which is based on a global marketplace, chemical fertilisers, advanced agricultural machinery, and a complex transportation network. Or we can conceive of a system which is based on locally produced, labour-intensive, organic2 farming methods. Each of these systems will have very different material implications.
The next stage in the representation is the design phase. This is the stage during which all kinds of aspects of the conceived system are planned and designed. In particular, of course, this must include the design of both products and production systems. Both of these elements will have significant impacts on the material aspects of the overall system.
Subsequent stages in the diagram represent the material processing and production stages discussed in Chapter 1. These stages produce the material products which are then distributed to the consumer to provide specific services. Having served their purpose, the degraded products then pass to a further material stage, which I have called here waste management. After passing through the waste management
sector, materials will leave the economic system and reenter the environment.
Often this last stage in the life of products is referred to as disposal. But this stage is not just a question of throwing materials away and forgetting about them. The product will depart from the economic system and even from our consciousness. But we should always remember that materials that we have disposed of continue to be subject to the laws of nature. Sometimes they degrade; sometimes they disperse; sometimes they accumulate; sometimes they rejoin material cycles of one kind or another; and sometimes they leak into soils and water supplies, causing environmental damage for generations to come. This is one of the prime motivations for developing a preventive environmental management strategy.
The preventive strategy itself is composed—as I described at the end of the previous chapter—of two principal avenues of intervention in the service system:
1 improvements in the material efficiency of the system; and
We could also identify another important general strategy, which is to reduce mixing of different kinds of materials within the system. From a thermodynamic viewpoint this mixing represents an increase in entropy within the system. From a practical point of view, mixed waste streams are much more difficult to deal with effectively than segregated streams.
Was this article helpful?