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close this bookEco-restructuring: Implications for sustainable development (UNU, 1998, 417 pages)
close this folderPart I: Restructuring resource use
close this folder4. Materials futures: Pollution prevention, recycling, and improved functionality
View the document(introductory text...)
View the documentEditor's introduction
View the documentBackground
View the documentStrategies to increase materials productivity
View the documentMaterials technology
View the documentMaterial attributes
View the documentMaterial performance trends
View the documentConclusions
View the documentNotes
View the documentReferences

Editor's introduction

This chapter addresses a key problem in the context of eco-restructuring, namely the extent of technological possibilities for radically increasing materials productivity. It will be recalled that two premises of the book are (1) that economic growth must continue, at least for the foreseeable future, and (2) that the nature of that growth must change radically in order to satisfy the basic requirements of long-run sustainability. That change has two fundamental implications. First, the fact that non-renewable resource stocks are finite dictates that the rate of extraction of non-renewable materials cannot increase significantly over its present level, globally, and must eventually approach zero. Second, the fact that the habitability of the earth for humans depends on the health of the biosphere dictates that the rate of emissions of chemically active - hence potentially harmful - wastes into the environment must be decreased even more drastically, and even sooner.

There are two generic strategies for reducing waste emissions. The first is known as "end-of-pipe" treatment. It is the strategy that has been favoured overwhelmingly up to now. And it will remain essential. But it is ultimately limited in its effectiveness by the fact that wastes can never be completely inert as long as they differ chemically or physically from the composition of the environmental medium into which they are discarded. The other generic approach is to reduce the use of materials, especially non-renewable extractive materials. This is often taken to imply a reduced standard of living, even reversion to a sort of Gandhian lifestyle. It need not imply any such thing. What it does imply is that the economy must generate much more output (GDP) for each unit of physical materials and energy input. In other words, the productivity of materials and energy must be sharply increased and must continue to increase over time.

To increase materials and energy productivity there are several approaches. One that has been discussed frequently in the past is "dematerialization", i.e. to use less material for a given function than in the past. This approach depends partly on scientific progress in materials science, enabling materials to perform better. It also depends on more mundane changes to encourage less wasteful practices in the materials cycle itself - especially less dependence on dissipative uses of materials (such as solvents, cleaning agents, pigments, lubricants, etc.) and more efficient re-use, recovery, and remanufacturing of durable goods. This approach is sometimes called "clean technology," to distinguish it from waste treatment.

When the use of materials is considered from a lifecycle perspective, it is clear that efficient recovery, repair, renovation, remanufacturing, and recycling depend very strongly on how the material is utilized in the first place. Products that are dissipated in use (such as solvents or detergents) cannot be recovered for re-use. Products that are very difficult to disassemble cannot be repaired, renovated, or remanufactured. Clearly, these "end-of-life" issues must be taken into account at the beginning, i.e. at the stage of product design. Design for environment (DFE) is an emerging discipline that attempts to deal with this aspect of the problem. DEE requires that products be designed not only for performance and low manufacturing cost, but also for long life, efficient disassembly, and remanu facturability, and - where remanufacturing is not possible - for efficient recycling.

Clearly the problem of increasing materials productivity raises an enormous number of peripheral issues with respect to needed material performance characteristics. The present chapter deals primarily with the latter.