Papers Delivered at International Conference on Cleaner Production
Beijing, China -- September 2001 -- Paper 9 of 30

Industrial Ecology and Its Relationship to Cleaner Production

J. Alan Brewster
(Yale School of Forestry & Environmental Studies, 
205 Prospect St., New Haven, CT 06511, USA)

Abstract: The concept behind the science of Industrial Ecology (IE) is that an industrial system should be viewed not in isolation from its surrounding systems, but in concert with them. Industrial Ecology is the systematic study of industrial systems in relation to natural and human systems designed to optimize the total materials cycle from virgin material, to finished material, to product, to obsolete product, and to ultimate disposal. Cleaner Production (CP) is essentially the application of IE to the improvement of production processes, products, and services to increase eco-efficiency and reduce risks to humans and the environment. Thus, in theory, the two concepts are intimately related and mutually reinforcing. In practice, both the science and its application in specific circumstances are relatively new and still evolving.

Keywords: Industrial Ecology, Cleaner Production

Introduction

Within the last 25 years, there has been a significant shift in approaches to environmental protection in many industrial sectors from cleaning up pollution to preventing or reducing pollution before it is released. This shift has gone by a variety of names over this period, including pollution prevention, eco-efficiency, and Cleaner Production. Regardless of what it is called, however, this shift in focus has led to greater emphasis on efficiency in the use of resources and energy, changing production processes and technologies, and substituting less polluting materials for more polluting ones. The emphasis of all these approaches on efficiency has led to recognition that these efforts can yield significant economic as well as environmental benefits.

Advances in Cleaner Production (CP) have been substantial in many areas of the world and growing awareness and promotion of CP, such as we are seeing in China and elsewhere, promise greater progress. But CP efforts often tend to focus on individual production processes, specific products, or individual hazardous materials, rather than examining the full extent of the environmental impacts of the entire range of industrial activities that modern economies entail.

In parallel with the growth of CP, scientists, engineers, industrial managers, and many others have begun to recognize that true long-term sustainability of our industrial economic systems will require that societies learn to break our dependence on single use throughput of natural resources and growing production of wastes. This dependence has led to unsustainable impacts on the environment and disruption of natural systems. Instead, we must develop “cyclical” production systems that increasingly reuse and recycle all materials. Similar to biological ecosystems in which one organism’s waste is the source of food for another organism, we must develop industrial systems in which there are no “wastes” but only residual materials that can be used to produce other useful products.[1] This recognition has led to the concept of Industrial Ecology (IE) and the development of a new area of scientific study the examines industrial systems in the context of the natural, social, and economic systems that surround them.

Definitions

1.1 Cleaner Production

The term Cleaner Production (CP) has evolved over time and there are a number of variations in the way it is defined. For example, sometimes CP is used interchangeably with “pollution prevention”, while at other times pollution prevention is defined as only one part of CP.[2] The United Nations Environment Programme (UNEP) defines Cleaner Production as:

The continuous application of an integrated preventive environmental strategy applied to processes, products, and services to increase overall efficiency and reduce risks to humans and the environment.

• Production processes: conserving raw materials and energy, eliminating toxic raw materials, and reducing the quantity and toxicity of all emissions and wastes.

• Products: reducing negative impacts along the life cycle of a product, from raw materials extraction to ultimate disposal.

• Services: incorporating environmental concerns into designing and delivering services.[3]

This definition of CP incorporates both a broad goal and a wide variety of approaches, but is largely rooted in the examination of existing processes, products, and services with a view to reducing risks to humans and the environment. Similarly, in addressing eco-efficiency CP generally starts with cost-effective environmental improvements from the perspective of the individual factory or industrial enterprise.[4]

This definition also describes a process ("the continuous application of an integrated preventive environmental strategy") rather than an outcome or end point. It recognizes that there are many different steps that can be taken to improve efficiency and reduce environmental risks and that some steps may be more difficult to take than others, requiring more time and financial resources. This process orientation also recognizes that we do not have all the answers to how to become more efficient and how to eliminate all waste. New knowledge and understanding of the physical and chemical properties of materials, their interactions, and of biological processes, may enable us to further reduce the environmental impacts of industrial processes. New technologies may enable us to enhance economic and environmental performance, at the same time. Implementing CP means continuing to apply the latest advances in knowledge and technology to achieve its goals.

1.2 Industrial Ecology

Where will this new knowledge come from and how will these new technologies be developed? This paper suggests that it is through the new and developing science of IE that we will acquire the knowledge and understanding and create the technologies necessary to "continuously…increase eco-efficiency and reduce risks to human health and the environment", which is the goal of CP.

In their path-breaking textbook, Industrial Ecology, Graedel and Allenby provide the following short definition of IE:

Industrial ecology is the means by which humanity can deliberately and rationally approach and maintain a desirable carrying capacity, given continued economic, cultural, and technological evolution. The concept requires that an industrial system be viewed not in isolation from its surrounding systems, but in concert with them. It is a systems view in which one seeks to optimize the total materials cycle from virgin material, to finished material, to component, to product, to obsolete product, and to ultimate disposal. Factors to be optimized include resources, energy, and capital.[5]

Like the definition of CP, this definition of IE has evolved over time and may continue to change. It shares similar goals with CP but puts more emphasis on the sustainability of industrial practices over time and more frequently looks beyond individual firms and their existing processes, products, and services.

• Industrial ecology involves looking not only at the toxicity of alternative resources that may be used in manufacturing a product, but also at the processes that produce those resources and what impacts they have on humans and the environment.

• IE means not only reducing the environmental impact of the process that goes into producing a product but also learning what becomes of the product after it is sold and used.

• IE means not only finding the most efficient and environmentally sound way of producing a particular product, but designing new products or services that meet the same demand as an existing product, with even better results for environmental sustainability.

• IE means not only looking at the impact of a firm’s wastes on the environment, but also looking at the cumulative impacts of industrial sectors and whole economies on global environmental systems.

Key Elements of Industrial Ecology

Industrial ecology is still a relatively new field of study, although there are growing numbers of people in universities, industry and governments who are exploring its dimensions -- both theoretical and practical. As such, there is no complete consensus on what constitutes IE and where its boundaries lie. The remainder of this paper will provide an outline of the conceptual framework of this new emerging scientific field, drawing heavily on the work of Reid Lifset and Thomas E. Graedel.[6] Following this outline, the paper will conclude by noting the areas in which IE and CP are most closely connected.

The concept of industrial ecology builds on the biological concept of ecology, which is "the branch of biology dealing with the relations of organisms to one another and to their physical surroundings."[7] Rather than examining an individual organism, ecology looks at the systems within which organisms live and of which they are a part. Individual organisms consume resources and leave wastes behind. When viewed on a large enough scale in space and time, however, organisms tend to live within natural ecosystems where resources are not depleted and wastes do not accumulate because there are cyclical processes in place that make use of all "wastes" as resource inputs (food) for other organisms.

In the history of Earth, large-scale natural systems have not lasted forever but they have often survived for tens of thousands or even millions of years. This kind of stability is possible only where the recycling of resources is essentially complete (with the exception of the constant input of solar energy.)

Industrial ecology seeks to move our industrial and economic systems toward a similar relationship with Earth's natural systems. Earth's resources are not infinite, so the pattern of industrial development that we have followed over the past two centuries, or so, cannot continue indefinitely, especially in the face of the rapid expansion of population and economic activity that the world has seen in the past fifty years. IE seeks to discover how industrial processes can become part of an essentially closed cycle of resource use and reuse in concert with the natural environmental systems in which we live.

To do this, IE (like biological ecology) looks beyond individual industrial processes to examine the interactions of industrial activities with the environment through a systems perspective.

The goal is to avoid narrow, partial analyses that can overlook important variables and, more importantly, lead to unintended consequences. The systems orientation is manifested in several different forms:

• use of a life cycle perspective,

• use of materials and energy flow analysis,

• use of systems modeling, and

• sympathy for multidisciplinary and interdisciplinary research and analysis.[8]

The life cycle perspective attempts to ensure that, in examining an industrial process or product, all of its interactions with and impacts on the environment are fully accounted for, from extraction of raw materials, to production processes, to product use and disposal. Life cycle assessment (LCA) is an important tool for both IE and CP and will be further discussed below.

Materials and energy flow analyses can be used both at the global and local levels. On the global level these flow analyses can help determine the extent to which human activities are disturbing the earth’s natural systems and cycles, including the hydrological cycle and critical biogeochemical cycles such as the carbon cycle and the nitrogen cycle. At a local or firm level, research methods that calculate the mass balances of industrial processes are used to ensure that all resources are fully accounted for.

Formal systems modeling enables IE researchers to not only capture the many elements involved in industrial systems and their surroundings, but also to begin to examine the interactions among them. Finally, interest in multidisciplinary and interdisciplinary research and analysis reflects the recognition that understanding industrial, natural, economic and social systems and their interactions requires the insights of may disciplines.

This broad conceptual framework leads IE into a wide range of activities that go well beyond research topics to practical concerns such as the design of new industrial processes and technologies, redefining the role of corporations in the effort to achieve sustainability, and modifying public policies to encourage resource reuse and recycling. It is, therefore, difficult to capture succinctly the various elements of IE in a coherent way. One approach is to characterize the elements of IE on various spatial scales. Lifset and Graedel suggest dividing IE activities into those that focus "at the firm or unit process level, at the inter-firm, district or sector level, and finally at the regional, national, or global level."[9] Fig. 1 depicts this division of IE activities into these different scales.

How Cleaner Production Relates to this Structure

Although all three scales are relevant to CP concerns, the greatest focus of CP has been on the firm or unit process level. The focus of IE on pollution prevention and eco-efficiency at this level is very much the same as focus as that of CP and the two fields reinforce each other. New knowledge gained from IE in these areas can have direct application to CP, while the practical lessons learned from implementing these elements of CP can serve to identify new areas for research.

Similarly, both CP and IE also share an interest in using a “design for environment” approach to further their objectives. Moving back in the production cycle to incorporate environmental concerns into the initial design objectives for both products and processes offers great opportunities for achieving the goals of CP, as well as IE.

At the “between firms” or sectoral level IE and CP continue to share some common approaches, particularly the use of product life-cycle-assessment methods and industrial sector initiatives. However, IE will more often extend the life-cycle-assessment analysis in both directions – further back toward the processes that yield the materials used in a product’s production and forward to give greater consideration to the environmental impacts of the use and disposal of a product after its useful life is over. Although life-cycle-assessment is listed for IE at the between firms level, CP is more likely to use it at the single firm level.

The focus at the between firms level on “industrial symbiosis” reflects the interest of IE in the potential for closing materials and energy loops by examining the ways in which the residual (waste) materials of one firm may be used by other firms as material or energy inputs. This potential is particularly interesting when these firms are located in close proximity to each other. This focus is not a main element of CP. CP tends to look primarily at reducing or eliminating wastes (especially toxic wastes) within a specific industrial process or firm, although there may be opportunities for even greater overall economic and environmental benefits by looking at larger industrial systems.

The focus of IE at the regional, national, and global level is not generally shared by those concerned with CP. Over time, however, as we learn more from IE about how our industrial and economic activities are affecting the earth’s natural systems, this understanding may require shifting attention in CP to different materials and processes.

Conclusion

Both IE and CP are still relatively new endeavors, which have developed over the past decade or so, in response to a growing awareness of the negative impacts of industrial activities on the natural and human environments. They share the common goal of reducing these negative impacts in order to reduce risks and to foster the sustainability of our economies and the environment. With this common goal, the relationships between IE and CP can perhaps be best characterized as follows.

• Industrial ecology is the science that can provide the new knowledge and which can lead to the new technologies that will enable CP to continue to make greater progress in achieving its goals of increasing eco-efficiency and reducing risks of industrial activities to humans and the environment.

• Cleaner production is the application of knowledge gained from the insights of IE to the practical tasks of improving production processes, products, and services. In the process of implementing its “integrated preventive environmental strategy” CP can illuminate the issues that IE must address.

Notes

1. Graedel, T. E. and B. R. Allenby, Industrial Ecology, pp. 93-96.

2. Baas, Leo, Reflections on Cleaner Production Terminology in Industry and Environment, Vol. 21, No 4, pp. 28-29.

3. UNEP

4. van Berkel, Rene, Esther Willems, and Marije Lafleur, The Relationship between Cleaner Production and Industrial Ecology in Journal of Industrial Ecology, Vol. 1, No 1, P. 52.

5. Graedel, T. E. and B. R. Allenby, Industrial Ecology, p. 9.

6. Lifset, Reid and Thomas E. Graedel, Industrial Ecology: Goals and Definitions in A Handbook of Industrial Ecology, (forthcoming).

7. Illustrated Oxford English Dictionary, p. 259.

8. Lifset, Reid and Thomas E. Graedel, Industrial Ecology: Goals and Definitions, p. 4.

9. Lifset, Reid and Thomas E. Graedel, Industrial Ecology: Goals and Definitions, p. 7.

10. Lifset, Reid and Thomas E. Graedel, Industrial Ecology: Goals and Definitions, p. 8.

References

1. Adriaanse, Albert, Stefan Bringezu, Allen Hammond, Yuichi Moriguchi, Eric Rodenburg, Donald Rogich, and Helmut Schütz, Resource Flows: The Material Basis of Industrial Economies, World Resources Institute, Washington, D.C., 1997.

2. Angel, David P and Michael T. Rock, eds., Asia’s Clean Revolution: Industry, Growth and the Environment. Greenleaf Publishing Limited, UK, 2000.

3. Bass, Leo, ‘Reflections on Cleaner Production Terminology’. Industry and Environment, volume 21, no. 4: 28-29, UNEP, France, 1998.

4. De Hoo, Sybren and Marcel Crul, Cleaner Production in China: Design of An Effective Policy Package and Action Plan, (informal document), 1997.

5. Ehrenfeld, John R, ‘Industrial Ecology: A Framework for Product and Process Design’. Journal Cleaner Production, no. 5: 87-95, Elsevier Science Ltd., Oxford, UK, 1997.

6. Graedel, Tom and B.R. Allenby, Industrial Ecology, Prentice Hall, Englewood Cliffs, New Jersey, 1995.

7. Graedel, Tom and Jennifer Howard-Grenville, ‘The Next Step: Pollution Prevention’. (forthcoming)

8. Lifset, Reid and Tom Graedel, ‘Industrial Ecology: Goals and Definitions’. A Handbook of Industrial Ecology, Edward Elgar Publishing, North Hampton, MA, (forthcoming)

9. Matthews, Emily, Christof Amann, Stefan Bringezu, Marina Fischer-Kowalski, Walter Hüttler, René Kleijn, Yuichi Moriguchi, Christian Ottke, Eric Rodenburg, Don Rogich, Heinz Schandl, Helmut Schütz, Ester Van Der Voet, and Helga Weisz, The Weight of Nations: Material Outflows from Industrial Economies, World Resources Institute, Washington, D.C., 2000.

10. Oldenburg, Kirsten U and Kenneth Geiser, ‘Pollution Prevention and…or Industrial Ecology’? Journal Cleaner Production, no. 5: 103-108, Elsevier Science Ltd., Oxford, UK, 1997.

11. Tu, Ruihe, ‘Promoting Cleaner Production in China: Overview and Outlook’. Industry and Environment, volume 21, no. 4: 30-36, UNEP, France, 1998.

12. Van Berkel, René, Marije Lafleur and Esther Willems, ‘The Relationship between Cleaner Production and Industrial Ecology’. Journal of Industrial Ecology, no.1: 51-66, MIT Press, Cambridge, MA, 1997