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Industrial ecology: a new field or only a metaphor?
Journal of Cleaner Production 12 (2004) 825–831 www.elsevier.com/locate/jclepro
Industrial ecology: a new field or only a metaphor? John Ehrenfeld School of Forestry and Environmental Sciences, Yale University, 205 Prospect Street, New Haven, CT 06511, USA
Abstract In the 10 years since industrial ecology first became a topic of academic interest, it has grown as a field of inquiry and has produced a community of practice in several sectors including academia, business, and government. Even as the shape of industrial ecology becomes clearer, questions remain as to its lasting power beyond the metaphor that gave it its distinctiveness. This paper examines the development of industrial ecology and assesses its progress towards becoming a field of academic inquiry. And, in a related analysis, I look at the progress industrial ecology has made in establishing itself as an institutional (cultural) basis for action in the above sectors. Ideas like industrial ecology must become institutionalized if they are to have much effect on the reality of everyday activities. # 2004 Elsevier Ltd. All rights reserved. Keywords: Industrial ecology; Metaphor; Field; Institutionalization
1. Introduction Following its start about a decade ago, industrial ecology has entered the world of academia, ecodesign, environmental policy, industrial development, and business strategy. This special issue on industrial ecology is evidence of its continuing evolution. In the first special issue on industrial ecology in the Journal of Cleaner Production in 1977, I argued that the then quite new set of ideas under the rubric of industrial ecology could serve as a new paradigm for process and product design [1]. In the larger sense of technological systems, the new framework could also serve as a template for the design of the institutional structures in which these technological artifacts that impact the environment arise and are applied. The basis of the argument was that industrial ecology had features unlike those underpinning the dominant social paradigm shaping the culture in most industrial economies, particularly those of the West. The important concepts were those taken by analogy from stable ecosystems and included, among others, new forms of cooperation, material recycling (loop-closing), interdependence, and Present address: International Society for Industrial Ecology, 24 Percy Road, Lexington, MA 02421, USA. http://www.is4ie.org Tel.: +1-781-861-0363; fax: +1-781-861-9531. E-mail address: [email protected] (J. Ehrenfeld).
0959-6526/$ - see front matter # 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.jclepro.2004.02.003
holistic communities. That these concepts, embedded in a broad systems orientation, can produce, in specific cases, artifacts and technological systems with less impact on ecological systems is not questioned [2]. The appropriateness and pragmatic value of the broad metaphorical sense of industrial ecology has not, however, achieved a consensus even among its users and advocates. Johansson questions ‘‘. . .whether this particular metaphor actually can be helpful in defining new strategies for industrial development’’ [3]. I will not attempt to respond directly to Johansson’s challenge in this paper, but he clearly sets out a critical task for those who now work in the field (if it is indeed a field)—to establish the utility of the metaphor in practice or perhaps more precisely to determine the bounds of its usefulness. Rather, I will address the evolution of industrial ecology as a field as evidence that the metaphor and underlying concepts and tools are becoming accepted and used by an increasing number of scholars and practitioners. Even Johansson points to the connection between metaphor and creativity. He states, ‘‘. . .the extension of the imagination beyond what is known as truth is their [metaphors’] very reason for existence, it [sic] is a tool for bringing creative imagination into science, and occasionally to a greater public.’’ [3]. It seems that industrial ecology is at a critical stage in its evolution. Many others who also maintain the importance of keeping the metaphor within limits
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echo the concerns that Johansson raises. On the other hand, the ideas are spreading into practice through a variety of avenues, some squarely within the ‘recognized’ boundaries of what goes for ‘industrial ecology’, and some that fall outside these borders. This paper is a progress report on the current state of industrial ecology. I first present the state of industrial ecology as a field of theory and practice, and then assess the degree to which the field has become institutionalized. By this, I mean to ask, how far has industrial ecology come in creating structures that produce routine action in selected domains, such as the academic or policy worlds? To the extent that industrial ecology has taken on the characteristics of a field, it is arguable that its metaphorical origins are becoming translated into more conventional scientific, technological and social truths. Beyond constituting a new field, questions about the practical relevance of industrial ecology require that one examine the nature of institutionalization going on around the field. The emergence of a new field recognized within the scientific community is evidence of the emergence of a new paradigm in Kuhn’s sense and of the development of a new set of normal practices [4]. But if industrial ecology is to penetrate beyond the scientific establishment into the everyday culture and influence the policy and strategy world to any appreciable extent, there must be evidence of institutionalization beyond the academy. Based on my own observations as a worker in the field for the past 10 years and especially drawing on my more recent experience as executive director of the International Society for Industrial Ecology, I examine these two questions in turn. And at the end I return to Johansson’s question.
2. Is industrial ecology a field? The first item following this brief introduction is the question of whether industrial ecology is a field at all. Alternatively, it might merely be a new set of ideas and methods that are at home within and expand the body of knowledge of some already established field. Another possibility is that industrial ecology constitutes an interdisciplinary field, drawing on ideas and technology from other fields. As a new field, as I argued in the introduction, it expands the minds (to use another metaphor) of its practitioners. New practices unconstrained by what is considered normal in established fields would be expected to emerge. To be considered a field, one might argue that there must be a set of constitutive attributes, including: 1. A set of foundational beliefs that lend a common meaning to all players in the field and allow
communication across the boundaries of the field or, otherwise stated, a cohesive set of concepts that guide practitioners in their everyday, normal activities. 2. Practical resources or sets of standard tools and practical guides like textbooks. 3. An authoritative structure maintaining quality and conceptual coherence. 4. A community of actors playing within the first three categories above. Let me examine each of these categories in turn. 2.1. Beliefs and concepts First, let me ask whether industrial ecology is based on a well-rooted foundational idea. I think so, although many would not agree. The ideas that have shaped industrial ecology began to emerge in the 1970s and even earlier in the work of one of the pioneers of the field, Robert Ayres. Ayres and his colleagues began to examine the flows of materials (and energy to a lesser extent) in systems ranging from river basins to whole economies under the rubric ‘industrial metabolism’, suggestive of the flows of energy and food within an ecological system [5,6]. About the same time, studies aimed at directing the Japanese economy towards less dependence on materials were initiated using the name ‘industrial ecology’ in the official title of the research/planning group doing the work [7]. And in a little known but significant book by a small group of Belgians published in 1983, industrial ecology was used to describe a view of the Belgian economy in terms of material and energy flows, instead of the usual economic monetary flows [8]. But none of these independent works caught the attention of academics or others interested in pursuing the ideas in any organized way. The situation changed in 1989 when Robert Frosch and Nicholas Gallopoulos published an article in a special issue of Scientific American in which they called for the restructuring of industry in the form of an ecosystem with materials (including those commonly held to be ‘wastes’) flowing through a myriad of interconnected production processes [9]. Wastes would be drastically reduced and demand for virgin materials would be similarly lowered. The publication of this article came at a time in the US when concerns about the long-term sustainability of the Earth were on the rise. Industrial ecology conveyed a powerful metaphoric alternative to the ways modern industrial societies had evolved—one that could rise above the profligate ways of the past. In terms of a single overriding theme based on these historical writings, industrial ecology springs from what has come to be called ‘the biological or ecological metaphor’ [10]. Whether present in an objective idea
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like ‘industrial metabolism’ [11], ‘closed industrial ecosystem’ [6], technological food webs [12] or industrial symbiosis [13], industrial ecology draws on some vision of an ecological network of interconnected actors exchanging matter and energy. Some see the metaphor as ontological—a way of extending the bounds of thinking [14]; others see the metaphor as normative, providing prescriptive guides for designing a more sustainable world [15]. As an objective guide for scientific inquiry, the ecological metaphor leads to such practices as: material flow accounting (MFA), substances flow analysis (SFA), life cycle analysis (LCA), studies of industrial symbioses, and more. Entropic and exergy-based analyses can be tied to thermodynamic properties of the steady-state behavior of stable ecosystems. These tools are being used in a societal scope, for example, to examine policy frameworks, resource management schemes, and economic performance in both current and historical contexts. At a finer scale, they are being used to look at industry and technology, for example, to compare alternative industrial forms of organization or product designs. These basic analytic notions, in turn, point to practical ideas such as dematerialization, product life extension, servicizing, industrial symbiosis, design for environment, green chemistry, and much more. Related to the normative perspective, some, including myself, have argued that industrial ecology is a new paradigm that can offer a conceptual base for finding solutions to what have been intractable problems [16,17]. As paradigms, objective notions like the ecological metaphor take on prescriptive or normative clothing as they become pragmatic responses to solution-seeking actors. In its prescriptive mode, the ecological metaphor can be found in the principles of the Natural Step [18] and Natural Capitalism [19], design for environment, and even in policies such as extended producer responsibility. The other half of the metaphor refers to industry. The field is focused on understanding the industrial basis of production, a characteristic of modern societies. Understanding the industrial systems of modern societies is held to be critical to designing new forms of production that are more sustainable. One of the concepts of Frosch and Gallopoulos was that of an industrial food web in which some firms used as feedstocks the wastes and by-products of others [6]. Instead of the common way of viewing an industrial economy as a collection of individual actors loosely coordinated by the price signals in a market, their paper established a systems orientation analogous to a natural ecosystem.
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2.2. Practical resources Regarding the resources that have become part of the practices of industrial ecology, one can point to a variety of analytical software packages and several standards for LCAs. While not so well developed as LCA, MFA methods have converged and one can find examples of national accounts following a consistent methodology [20]. Within industry, industrial ecology is applied through design for environment (DfE) practices. Most DfE schemes involve some form of LCA. Standardized DfE methods have been widely applied in all industrialized regions of the globe [21]. A handful of texts have been written (for example, the groundbreaking text by Graedel and Allenby [22]) and are being used in the teaching programs at university level courses. Following early work in structural economics by Duchin and Lange [23], a few scholars are now using input/output modeling taken from economics and are applying it to material flow systems. A comprehensive Handbook of Industrial Ecology was published in 2002 [2]. 2.3. Authority The Journal of Industrial Ecology, now entering its sixth year, has attained a reputation ascribed to peerreviewed journals in well-established fields. The Journal and the peer review process lend disciplinary legitimacy to industrial ecology. The prestigious US National Academy of Engineering took the idea under its wings in its early days and provided financial support and an authoritative umbrella. Activities that began under the auspices of the National Academy of Engineering in the early 1990s spawned many of the first publications and texts in the field. Their early convening role in the US has shifted to the Gordon Research Conferences. Unlike the typical Gordon conferences with a narrow focus on a specific sub-discipline or research topic of particular current relevance, the first industrial ecology Gordon Conference in 1998 was part of an experiment to broaden the series to include interdisciplinary and ‘policy’ themes. In spite of some rocky moments and questions about the rigor of the industrial ecology sessions, this topic seems to have become a regular player and was included again in the 2002 series. 2.4. The industrial ecology community At the 1998 Gordon Conference on industrial ecology, many of the attendees started to talk about forming some sort of society for industrial ecology. The idea was pursued further by a small group of Japanese, European, and US workers who developed white papers about the possible shape of a new society. At
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the June 2000 Gordon Conference, participants discussed the subject of forming a new society for industrial ecology. With virtually unanimous support, a steering committee was formed to take positive steps to get organized. The outcome of this exploratory work was a new professional society, the International Society for Industrial Ecology, that serves to build a community and to legitimize the activities of its practitioners. In mid-2001, having raised some seed money to get going, the International Society for Industrial Ecology was launched formally and began to accept members. About 450 joined in the first year of operation. Membership numbers have remained level even after renewals were required for the first time. Although open to all communities of practice, the members, so far, have come largely from academia. The Society has been designed to provide many venues and media for dialogue and communication. The Journal of Industrial Ecology was adopted as the ‘official’ journal of the Society and is packaged with membership. The Society held its first International Meeting in late-2001 in Nordwijkerhout, The Netherlands. By all accounts, it was a very successful launch, with almost 300 present from all quarters of the globe. A second International Meeting was held in June 29–July 2, 2003, in Ann Arbor, MI.
artifacts, policy making, housekeeping, and so on. The inclusion of ‘routine’ is essential since the idea of an institution is always associated with activities that follow a recognizable pattern over time and space. If one looks at models of institutionalization for broad social activities, one will hear reference to structuration, culture, habitus, rationality, and many other ways of talking about the constitutive bases of action [16]. All have several features in common. One way of analytically categorizing institutional structures includes the following: 1. A system of beliefs about how the world works, 2. Strategies and norms governing what one should do when addressing a particular domain of action, 3. A common set of tools and technologies to be used towards meeting one’s objectives in that domain, and 4. A set of legitimating authorities. The point of this rather academic discussion is to note that one can observe the position of constellations of ideas, norms, and tools in domains of action and assess the degree to which the always-changing institutionalization process has incorporated them. With this introduction, let me look at a few domains and comment on the progress of industrial ecology or, more accurately, the lack of progress in many. I will look at academia, industrial strategy, and government policy.
3. The institutionalization of industrial ecology 3.1. Academia Given that in its first 10 years, ‘industrial ecology’ has not become a ‘household word’, it seems appropriate to check into its status as an institution. The discussion so far indicates that industrial ecology is now or is on the way to becoming a field, but the question remains as to whether this process is likely to last. In a related question, one must ask whether industrial ecology has much power to influence activities outside a very narrow sphere. While the theories that now constitute industrial ecology make academic sense to many, it is the promise of new practices arising from the concepts that has brought many into the field. The importance of examining the institutionalization process springs from the aspirations of many who have been involved in the development of the field. This group believes that industrial ecology should or can become a force in producing a sustainable world. Graedel and Allenby have called industrial ecology ‘the science of sustainability’ [18]. Ehrenfeld has argued that industrial ecology is a new paradigm with the potential to break through the stalemate in the game of sustainability [13]. What I mean by an institution is a set of rules or structures that governs routine actions in some domain or domains, for example, academic research, design of
The best example of the penetration of industrial ecology into the academic world is the program at the NTNU in Trondheim, Norway. This program has become accepted as a ‘normal’ academic activity, with a faculty, a degree program at both the undergraduate professional and Ph.D. research levels, and a research portfolio. The normal character is evidence of institutionalization. The NTNU program takes students from traditional engineering and other technical disciplines after two years in the home department, and provides special courses and practicums in industrial ecology along with continuing work in the home over the next three years. The students graduate with a degree in the home discipline and a sub-specialization in industrial ecology. The NTNU program straddles the boundary between the old academic structures and the new field of industrial ecology, reflecting the practical realities of introducing a new program into a well-established set of academic and professional distinctions. If one looks at other places, there is scant evidence of such normalization of industrial ecology in academia. A few other universities are building programs centered or based on industrial ecology, for example the Yale School of Forestry and Environmental Management and the
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University of Troyes in France. The Mount Royal College in Alberta, Canada, initiated a degree program in 2001. Although these programs signal some small degree of institutionalization, progress here is slow, with little or no presence of industrial ecology at most universities. Past support from the US National Academy of Engineering and its equivalent in Norway, the NTVA, indicates recognition from the research community that industrial ecology represents a legitimate sphere of activity. Adding to this evidence are the three past summer industrial ecology research meetings under the aegis of the Gordon Research Conferences (GRC) in the US. The GRC is a well-established and highly regarded venue for members of the scientific research community. Another positive sign is the success of the Journal of Industrial Ecology. No field can become successfully accepted as a bona fide academic field without a high-grade journal or two. Readership has approached almost 1000 in 2002. The systems orientation of industrial ecology empowers it to be able to address questions beyond the scope of many other, more narrowly circumscribed disciplines. This characteristic of industrial ecology answers, in part, calls for the establishment of interdisciplinarity with sufficient power and breadth to cope with today’s complex socio-technical problems. The institutionalization process of industrial ecology has been helped along by the presence of researchers from many other established fields. In a sense, industrial ecology is a ‘melting pot’ for these immigrants from other fields. 3.2. Industry The application of industrial ecology in industry is growing more and more rooted. AT&T, and later Lucent, one of the successor firms left after AT&T broke itself into several pieces, supported industrial ecology through the appointment of research fellows at both large and small universities. Each appointment carried a small stipend for research. Lucent joined with the National Science Foundations to continue the research grant program but eventually stopped designating fellows. Although not universally accepted, the use of LCA is found in most well-established consumer products companies. The ISO 14000 environmental management standard contains a standard for LCA (ISO 14040–43). The Society of Environmental Toxicology and Chemistry (SETAC) has developed another, also widely accepted, framework. Supply chain protocols, now in place for many large products-oriented companies, frequently require that suppliers to these companies carry out LCAs. One can purchase a variety of software
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packages for LCAs. A new LCA coordination center has been started in the US. At a more strategic level, one can find several ‘proprietary’ systems in place. These include The Natural Step [14], Natural Capitalism [15], the McDonough and Braungart Scheme (‘‘Waste equals food’’) [24], and others. One of the four pillars of Natural Capitalism is ‘the flow economy’, a direct analog to an ecological network. This book has become one of the best selling volumes ever in the field of environment and sustainability. The Natural Step is based on a set of principles related to the ecological metaphor. The fundamental prescriptive basis of The Natural Step is the exhortation that human societies must close material cycles and prevent the accumulation of natural and manmade substances in the biosphere—the ecological system that supports all life. While none of these approaches come from activities strictly or historically located within industrial ecology (IE), all are based on or incorporate a set of strategic or design principles traceable to the ecological metaphor. In private conversations, I have been asked whether there is any difference between industrial ecology and programs like The Natural Step or parts of Natural Capitalism. These programs share the same ecological metaphor and focus on industrial production as part of their conceptual bases. They also incorporate prescriptive norms (for example, closed material loops), but offer different tools and structures of legitimacy. Industrial ecology comes from more academic roots, with its focus on analysis, for example, LCA or MFA. The Natural Step directs its prescriptions to the strategic level in firms and other organizations following a compass metaphor. Industrial ecology draws its legitimacy largely from academic sources. The Natural Step has attempted to become legitimated through a quasi-academic process in Sweden as well as popular support including that of the King of Sweden. Industrial ecology must expand its legitimacy beyond the academic world if it is to gain a foothold in other domains. From what little evidence can be found, it would appear that this key aspect of the institutionalization process has not occurred or is happening at a very slow pace. Most of the members of the new Society and almost all the papers submitted for presentation at the Inaugural Meeting have come from academia, with only a smattering from industry, government, or other sectors. 3.3. Government IE has also moved slowly in the government sector. But there are signs of embedding, especially in Europe, where a few of its basic concepts have been used as a basis of policy design. Extended producer responsibility (EPR) has become a part of EU policy as a framework
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for moving towards a closed-loop society. While also recognized as important in the US, EPR has not, however, made it into formal government policy. Chain management remains a facet of the emergent Integrated Product Policy in the EU. Material flow accounting is beginning to show up in the national statistical accounting practices of a few countries. A conference devoted to this subject was held in Sweden in the spring of 2001. An earlier OECD working group special session noted that ‘there are several uses of MFA that are relevant for decision-makers’ [25]. This set of practices, although not yet widely influencing the policy process, is being moved along by the formation of an international group of industrial ecology practitioners and economists from national bureaus that has convened several meetings and gathered around some common research themes. The USEPA convened a workshop in 2000 to examine the potential for industrial ecology in the US regulatory and environmental policy world. They maintain a small task force to track this subject. A set of strategies based on industrial ecology was included in the final report of President Clinton’s Commission for Sustainable Development [26]. The US National Science Foundation, as noted earlier, co-sponsored an industrial ecology research grants program for several years.
4. Conclusion The predominant work within industrial ecology to date has been based on the flow aspects of the ecological metaphor—LCA, MFA, exergy analysis, for example. Less has been done to explicate its structural or systems aspects such as interdependence, closedloop, community, or locality [27]. Studies of industrial complexes and of symbiosis (another ecological systems arrangement) are as yet at an early stage and have yet to receive the same scale of attention that the flow aspects have. One of the persistent unanswered questions about industrial ecology is whether these systems characteristics are normatively desirable. Another variant of Johansson’s question is, ‘‘Is it always a good idea to close loops or create an industrial symbiosis?’’ Much more research is needed to establish this aspect of the basic metaphor as paradigmatic, or, in a less sweeping claim, to delineate the bounds where the prescriptions derivable from industrial ecology hold true. If this does not happen, industrial ecology may become strongly criticized as mere ‘wishful thinking’, or perhaps in even stronger terms as intellectual dishonesty, for going beyond the scientific justification of a metaphor-in-use [3]. In a recent book, Consilience, E.O. Wilson argues for a coalescing of all of human knowledge into a unified whole [28]. Consilience is a rarely used word meaning a
jumping together. The idea suggests one potential goal for industrial ecology—to continue to draw in theorists and practitioners from many disciplines or fields that have become separated by the inexorable processes of modernist epistemology. In the sense of consilience, it will be very important to refine the language of industrial ecology and find a vocabulary in common with those working in other related ‘fields’ and practices that share all or parts of the metaphor. Whereas academic fields seem to proliferate unendingly, grounding new paradigms or routines in industrial practice is much more difficult. The relative pace of institutionalization between these two sectors bears this out. More work is demanded to demonstrate the benefits of bringing industrial ecology into the everyday world of business than is needed to support the creation of a new academic field. Business schools have been slow to pick up environment or sustainability as a legitimate area for research and teaching, and we can expect little attention to be paid to industrial ecology in the near term. The economics cultural base of most business schools produces blindness to the real links between business activities and the natural system of the Earth. The interdependent, community, systemsview of industrial ecology is more likely to be taken up by scholars nipping at the boundaries that now constitute business school curricula (and other fields as well). My own assessment of the near future for industrial ecology is positive. Evidence of unsustainability continues to grow in spite of efforts arising in every sector to turn the tide. Technological innovation still holds the high ground as the most promising potential path towards sustainability. But it is becoming evident that innovative processes for a sustainable future must depart from those of the past. It seems that ecoefficiency, the ubiquitous slogan of global industry, has a dark side. The so-called rebound effect, in which efficiency produces more consumer surplus, which then creates more consumption, may counterbalance much of the potential benefits of eco-efficiency. Perhaps the concepts of industrial ecology can guide innovation in a direction where the demands on the ecosystem continue to decline or are stabilized as more and more people on the Earth have their needs satisfied. As I noted earlier, while there is current criticism (which criticism is likely to continue into the future) about the scientific basis of the ecological metaphor, there is little or no argument that the industrial ecology metaphor can serve as a powerful tool to get the creative process going. And there is also little or no argument that such creativity is sorely needed to address the daunting problems facing both rich and poor, or industrialized and developing countries alike.
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References [1] Ehrenfeld JR. Journal of Cleaner Production 1997;5(1–2):87–95. [2] Ayres RU, Ayres LW, editors. A handbook of industrial ecology. Cheltenham (UK): Edward Elgar; 2002. [3] Johansson A. In: Ayres RU, Ayres LW, editors. A handbook of industrial ecology. Cheltenham (UK): Edward Elgar; 2002. [4] Kuhn T. The structure of scientific revolutions, 2nd ed., enlarged. Chicago: University of Chicago Press; 1970. [5] Ayres RU, Kneese AV. Production, consumption, and externalities. Washington (DC): Resources for the Future; 1969. [6] Ayres RU. In: Ausubel JH, Sladovich HE, editors. Technology and environment. Washington (DC): National Academy Press; 1989, p. 23–49. [7] Watanabe C. Industrial-ecology: introduction of ecology into industrial policy. Tokyo: Ministry of International Trade and Industry (MITI); 1972. [8] Billen G, Toussaint F, Peeters P, Sapir M, Steenhout A, Vanderborght J-P. L’e´cosyste`me belgique. Essai d’e´cologie industrielle. Brussels: Centre de Recherche et d’Information socio-politique (CRISP); 1983. [9] Frosch R, Gallopoulos N. Scientific American 1989;September:142–55. [10] Allenby BR, Cooper WE. Total Quality Environmental Management 1994;3(3):343–54. [11] Ayres RU, Simonis UE, editors. Industrial metabolism: restructuring for sustainable development. Tokyo: United Nations University Press; 1994. [12] Graedel T. Annual review of energy and the environment. Palo Alto (CA): Annual Reviews, Inc.; 1996, p. 69–98. [13] Ehrenfeld JR, Gertler N. Journal of Industrial Ecology 1997;1(1):67–79. [14] Isenmann R. Industrial ecology: paradigmatic shift of understanding nature. The 2002 International Sustainable Develop-
[15] [16]
[17] [18]
[19]
[20]
[21] [22] [23]
[24] [25] [26] [27] [28]
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ment Research Conference, Manchester, UK, April 8–9, 2002. Shipley (UK): ERP Environment; 2002, p. 261–702002, p. 261– 70. Commoner B. The closing circle: nature, man and technology. New York: Knopf; 1971. Ehrenfeld JR. Industrial ecology: a new framework for product and process design. Journal of Cleaner Production 1997;5(1–2): 87–95. Ehrenfeld JR. American Behavioral Scientist 2000;22(2): 229–244. Robe`rt K-H. The natural step: a framework for achieving sustainability in our organizationsInnovations in management series. Cambridge (MA): Pegasus Communications, Inc.; 1997. Hawken P, Lovins A, Lovins LH. Natural capitalism: creating the next industrial revolution. Boston: Little, Brown and Company; 1999. Matthews E, et al. The weight of nations: material outflows from industrial economies. Washington (DC): World Resources Institute; 2000. Guine´e JB, editor. Handbook on life cycle assessment. Dordrecht (The Netherlands): Kluwer Academic Publishers; 2002. Graedel TE, Allenby BR. Industrial ecology. Englewood Cliffs (NJ): Prentice Hall; 1995 [now in its second edition]. Duchin F, Lange G. The future of the environment: ecological economics and technological change. New York: Oxford University Press; 1994. McDonough W, Braungart M. Atlantic Monthly. 1998. Anonymous. Special Session on Material Flow Accounting, Chair’s Summary. OECD, Paris, October 24, 2000. Anonymous. Sustainable America: a new consensus. President’s Council on Sustainable Development, Washington, DC, 1996. Korhonen J. Journal of Cleaner Production 2001;9:253–9. Wilson EO. Consilience: the unity of science. New York: Knopf; 1998.
Industrial ecology: a new field or only a metaphor? John Ehrenfeld School of Forestry and Environmental Sciences, Yale University, 205 Prospect Street, New Haven, CT 06511, USA
Abstract In the 10 years since industrial ecology first became a topic of academic interest, it has grown as a field of inquiry and has produced a community of practice in several sectors including academia, business, and government. Even as the shape of industrial ecology becomes clearer, questions remain as to its lasting power beyond the metaphor that gave it its distinctiveness. This paper examines the development of industrial ecology and assesses its progress towards becoming a field of academic inquiry. And, in a related analysis, I look at the progress industrial ecology has made in establishing itself as an institutional (cultural) basis for action in the above sectors. Ideas like industrial ecology must become institutionalized if they are to have much effect on the reality of everyday activities. # 2004 Elsevier Ltd. All rights reserved. Keywords: Industrial ecology; Metaphor; Field; Institutionalization
1. Introduction Following its start about a decade ago, industrial ecology has entered the world of academia, ecodesign, environmental policy, industrial development, and business strategy. This special issue on industrial ecology is evidence of its continuing evolution. In the first special issue on industrial ecology in the Journal of Cleaner Production in 1977, I argued that the then quite new set of ideas under the rubric of industrial ecology could serve as a new paradigm for process and product design [1]. In the larger sense of technological systems, the new framework could also serve as a template for the design of the institutional structures in which these technological artifacts that impact the environment arise and are applied. The basis of the argument was that industrial ecology had features unlike those underpinning the dominant social paradigm shaping the culture in most industrial economies, particularly those of the West. The important concepts were those taken by analogy from stable ecosystems and included, among others, new forms of cooperation, material recycling (loop-closing), interdependence, and Present address: International Society for Industrial Ecology, 24 Percy Road, Lexington, MA 02421, USA. http://www.is4ie.org Tel.: +1-781-861-0363; fax: +1-781-861-9531. E-mail address: [email protected] (J. Ehrenfeld).
0959-6526/$ - see front matter # 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.jclepro.2004.02.003
holistic communities. That these concepts, embedded in a broad systems orientation, can produce, in specific cases, artifacts and technological systems with less impact on ecological systems is not questioned [2]. The appropriateness and pragmatic value of the broad metaphorical sense of industrial ecology has not, however, achieved a consensus even among its users and advocates. Johansson questions ‘‘. . .whether this particular metaphor actually can be helpful in defining new strategies for industrial development’’ [3]. I will not attempt to respond directly to Johansson’s challenge in this paper, but he clearly sets out a critical task for those who now work in the field (if it is indeed a field)—to establish the utility of the metaphor in practice or perhaps more precisely to determine the bounds of its usefulness. Rather, I will address the evolution of industrial ecology as a field as evidence that the metaphor and underlying concepts and tools are becoming accepted and used by an increasing number of scholars and practitioners. Even Johansson points to the connection between metaphor and creativity. He states, ‘‘. . .the extension of the imagination beyond what is known as truth is their [metaphors’] very reason for existence, it [sic] is a tool for bringing creative imagination into science, and occasionally to a greater public.’’ [3]. It seems that industrial ecology is at a critical stage in its evolution. Many others who also maintain the importance of keeping the metaphor within limits
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echo the concerns that Johansson raises. On the other hand, the ideas are spreading into practice through a variety of avenues, some squarely within the ‘recognized’ boundaries of what goes for ‘industrial ecology’, and some that fall outside these borders. This paper is a progress report on the current state of industrial ecology. I first present the state of industrial ecology as a field of theory and practice, and then assess the degree to which the field has become institutionalized. By this, I mean to ask, how far has industrial ecology come in creating structures that produce routine action in selected domains, such as the academic or policy worlds? To the extent that industrial ecology has taken on the characteristics of a field, it is arguable that its metaphorical origins are becoming translated into more conventional scientific, technological and social truths. Beyond constituting a new field, questions about the practical relevance of industrial ecology require that one examine the nature of institutionalization going on around the field. The emergence of a new field recognized within the scientific community is evidence of the emergence of a new paradigm in Kuhn’s sense and of the development of a new set of normal practices [4]. But if industrial ecology is to penetrate beyond the scientific establishment into the everyday culture and influence the policy and strategy world to any appreciable extent, there must be evidence of institutionalization beyond the academy. Based on my own observations as a worker in the field for the past 10 years and especially drawing on my more recent experience as executive director of the International Society for Industrial Ecology, I examine these two questions in turn. And at the end I return to Johansson’s question.
2. Is industrial ecology a field? The first item following this brief introduction is the question of whether industrial ecology is a field at all. Alternatively, it might merely be a new set of ideas and methods that are at home within and expand the body of knowledge of some already established field. Another possibility is that industrial ecology constitutes an interdisciplinary field, drawing on ideas and technology from other fields. As a new field, as I argued in the introduction, it expands the minds (to use another metaphor) of its practitioners. New practices unconstrained by what is considered normal in established fields would be expected to emerge. To be considered a field, one might argue that there must be a set of constitutive attributes, including: 1. A set of foundational beliefs that lend a common meaning to all players in the field and allow
communication across the boundaries of the field or, otherwise stated, a cohesive set of concepts that guide practitioners in their everyday, normal activities. 2. Practical resources or sets of standard tools and practical guides like textbooks. 3. An authoritative structure maintaining quality and conceptual coherence. 4. A community of actors playing within the first three categories above. Let me examine each of these categories in turn. 2.1. Beliefs and concepts First, let me ask whether industrial ecology is based on a well-rooted foundational idea. I think so, although many would not agree. The ideas that have shaped industrial ecology began to emerge in the 1970s and even earlier in the work of one of the pioneers of the field, Robert Ayres. Ayres and his colleagues began to examine the flows of materials (and energy to a lesser extent) in systems ranging from river basins to whole economies under the rubric ‘industrial metabolism’, suggestive of the flows of energy and food within an ecological system [5,6]. About the same time, studies aimed at directing the Japanese economy towards less dependence on materials were initiated using the name ‘industrial ecology’ in the official title of the research/planning group doing the work [7]. And in a little known but significant book by a small group of Belgians published in 1983, industrial ecology was used to describe a view of the Belgian economy in terms of material and energy flows, instead of the usual economic monetary flows [8]. But none of these independent works caught the attention of academics or others interested in pursuing the ideas in any organized way. The situation changed in 1989 when Robert Frosch and Nicholas Gallopoulos published an article in a special issue of Scientific American in which they called for the restructuring of industry in the form of an ecosystem with materials (including those commonly held to be ‘wastes’) flowing through a myriad of interconnected production processes [9]. Wastes would be drastically reduced and demand for virgin materials would be similarly lowered. The publication of this article came at a time in the US when concerns about the long-term sustainability of the Earth were on the rise. Industrial ecology conveyed a powerful metaphoric alternative to the ways modern industrial societies had evolved—one that could rise above the profligate ways of the past. In terms of a single overriding theme based on these historical writings, industrial ecology springs from what has come to be called ‘the biological or ecological metaphor’ [10]. Whether present in an objective idea
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like ‘industrial metabolism’ [11], ‘closed industrial ecosystem’ [6], technological food webs [12] or industrial symbiosis [13], industrial ecology draws on some vision of an ecological network of interconnected actors exchanging matter and energy. Some see the metaphor as ontological—a way of extending the bounds of thinking [14]; others see the metaphor as normative, providing prescriptive guides for designing a more sustainable world [15]. As an objective guide for scientific inquiry, the ecological metaphor leads to such practices as: material flow accounting (MFA), substances flow analysis (SFA), life cycle analysis (LCA), studies of industrial symbioses, and more. Entropic and exergy-based analyses can be tied to thermodynamic properties of the steady-state behavior of stable ecosystems. These tools are being used in a societal scope, for example, to examine policy frameworks, resource management schemes, and economic performance in both current and historical contexts. At a finer scale, they are being used to look at industry and technology, for example, to compare alternative industrial forms of organization or product designs. These basic analytic notions, in turn, point to practical ideas such as dematerialization, product life extension, servicizing, industrial symbiosis, design for environment, green chemistry, and much more. Related to the normative perspective, some, including myself, have argued that industrial ecology is a new paradigm that can offer a conceptual base for finding solutions to what have been intractable problems [16,17]. As paradigms, objective notions like the ecological metaphor take on prescriptive or normative clothing as they become pragmatic responses to solution-seeking actors. In its prescriptive mode, the ecological metaphor can be found in the principles of the Natural Step [18] and Natural Capitalism [19], design for environment, and even in policies such as extended producer responsibility. The other half of the metaphor refers to industry. The field is focused on understanding the industrial basis of production, a characteristic of modern societies. Understanding the industrial systems of modern societies is held to be critical to designing new forms of production that are more sustainable. One of the concepts of Frosch and Gallopoulos was that of an industrial food web in which some firms used as feedstocks the wastes and by-products of others [6]. Instead of the common way of viewing an industrial economy as a collection of individual actors loosely coordinated by the price signals in a market, their paper established a systems orientation analogous to a natural ecosystem.
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2.2. Practical resources Regarding the resources that have become part of the practices of industrial ecology, one can point to a variety of analytical software packages and several standards for LCAs. While not so well developed as LCA, MFA methods have converged and one can find examples of national accounts following a consistent methodology [20]. Within industry, industrial ecology is applied through design for environment (DfE) practices. Most DfE schemes involve some form of LCA. Standardized DfE methods have been widely applied in all industrialized regions of the globe [21]. A handful of texts have been written (for example, the groundbreaking text by Graedel and Allenby [22]) and are being used in the teaching programs at university level courses. Following early work in structural economics by Duchin and Lange [23], a few scholars are now using input/output modeling taken from economics and are applying it to material flow systems. A comprehensive Handbook of Industrial Ecology was published in 2002 [2]. 2.3. Authority The Journal of Industrial Ecology, now entering its sixth year, has attained a reputation ascribed to peerreviewed journals in well-established fields. The Journal and the peer review process lend disciplinary legitimacy to industrial ecology. The prestigious US National Academy of Engineering took the idea under its wings in its early days and provided financial support and an authoritative umbrella. Activities that began under the auspices of the National Academy of Engineering in the early 1990s spawned many of the first publications and texts in the field. Their early convening role in the US has shifted to the Gordon Research Conferences. Unlike the typical Gordon conferences with a narrow focus on a specific sub-discipline or research topic of particular current relevance, the first industrial ecology Gordon Conference in 1998 was part of an experiment to broaden the series to include interdisciplinary and ‘policy’ themes. In spite of some rocky moments and questions about the rigor of the industrial ecology sessions, this topic seems to have become a regular player and was included again in the 2002 series. 2.4. The industrial ecology community At the 1998 Gordon Conference on industrial ecology, many of the attendees started to talk about forming some sort of society for industrial ecology. The idea was pursued further by a small group of Japanese, European, and US workers who developed white papers about the possible shape of a new society. At
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the June 2000 Gordon Conference, participants discussed the subject of forming a new society for industrial ecology. With virtually unanimous support, a steering committee was formed to take positive steps to get organized. The outcome of this exploratory work was a new professional society, the International Society for Industrial Ecology, that serves to build a community and to legitimize the activities of its practitioners. In mid-2001, having raised some seed money to get going, the International Society for Industrial Ecology was launched formally and began to accept members. About 450 joined in the first year of operation. Membership numbers have remained level even after renewals were required for the first time. Although open to all communities of practice, the members, so far, have come largely from academia. The Society has been designed to provide many venues and media for dialogue and communication. The Journal of Industrial Ecology was adopted as the ‘official’ journal of the Society and is packaged with membership. The Society held its first International Meeting in late-2001 in Nordwijkerhout, The Netherlands. By all accounts, it was a very successful launch, with almost 300 present from all quarters of the globe. A second International Meeting was held in June 29–July 2, 2003, in Ann Arbor, MI.
artifacts, policy making, housekeeping, and so on. The inclusion of ‘routine’ is essential since the idea of an institution is always associated with activities that follow a recognizable pattern over time and space. If one looks at models of institutionalization for broad social activities, one will hear reference to structuration, culture, habitus, rationality, and many other ways of talking about the constitutive bases of action [16]. All have several features in common. One way of analytically categorizing institutional structures includes the following: 1. A system of beliefs about how the world works, 2. Strategies and norms governing what one should do when addressing a particular domain of action, 3. A common set of tools and technologies to be used towards meeting one’s objectives in that domain, and 4. A set of legitimating authorities. The point of this rather academic discussion is to note that one can observe the position of constellations of ideas, norms, and tools in domains of action and assess the degree to which the always-changing institutionalization process has incorporated them. With this introduction, let me look at a few domains and comment on the progress of industrial ecology or, more accurately, the lack of progress in many. I will look at academia, industrial strategy, and government policy.
3. The institutionalization of industrial ecology 3.1. Academia Given that in its first 10 years, ‘industrial ecology’ has not become a ‘household word’, it seems appropriate to check into its status as an institution. The discussion so far indicates that industrial ecology is now or is on the way to becoming a field, but the question remains as to whether this process is likely to last. In a related question, one must ask whether industrial ecology has much power to influence activities outside a very narrow sphere. While the theories that now constitute industrial ecology make academic sense to many, it is the promise of new practices arising from the concepts that has brought many into the field. The importance of examining the institutionalization process springs from the aspirations of many who have been involved in the development of the field. This group believes that industrial ecology should or can become a force in producing a sustainable world. Graedel and Allenby have called industrial ecology ‘the science of sustainability’ [18]. Ehrenfeld has argued that industrial ecology is a new paradigm with the potential to break through the stalemate in the game of sustainability [13]. What I mean by an institution is a set of rules or structures that governs routine actions in some domain or domains, for example, academic research, design of
The best example of the penetration of industrial ecology into the academic world is the program at the NTNU in Trondheim, Norway. This program has become accepted as a ‘normal’ academic activity, with a faculty, a degree program at both the undergraduate professional and Ph.D. research levels, and a research portfolio. The normal character is evidence of institutionalization. The NTNU program takes students from traditional engineering and other technical disciplines after two years in the home department, and provides special courses and practicums in industrial ecology along with continuing work in the home over the next three years. The students graduate with a degree in the home discipline and a sub-specialization in industrial ecology. The NTNU program straddles the boundary between the old academic structures and the new field of industrial ecology, reflecting the practical realities of introducing a new program into a well-established set of academic and professional distinctions. If one looks at other places, there is scant evidence of such normalization of industrial ecology in academia. A few other universities are building programs centered or based on industrial ecology, for example the Yale School of Forestry and Environmental Management and the
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University of Troyes in France. The Mount Royal College in Alberta, Canada, initiated a degree program in 2001. Although these programs signal some small degree of institutionalization, progress here is slow, with little or no presence of industrial ecology at most universities. Past support from the US National Academy of Engineering and its equivalent in Norway, the NTVA, indicates recognition from the research community that industrial ecology represents a legitimate sphere of activity. Adding to this evidence are the three past summer industrial ecology research meetings under the aegis of the Gordon Research Conferences (GRC) in the US. The GRC is a well-established and highly regarded venue for members of the scientific research community. Another positive sign is the success of the Journal of Industrial Ecology. No field can become successfully accepted as a bona fide academic field without a high-grade journal or two. Readership has approached almost 1000 in 2002. The systems orientation of industrial ecology empowers it to be able to address questions beyond the scope of many other, more narrowly circumscribed disciplines. This characteristic of industrial ecology answers, in part, calls for the establishment of interdisciplinarity with sufficient power and breadth to cope with today’s complex socio-technical problems. The institutionalization process of industrial ecology has been helped along by the presence of researchers from many other established fields. In a sense, industrial ecology is a ‘melting pot’ for these immigrants from other fields. 3.2. Industry The application of industrial ecology in industry is growing more and more rooted. AT&T, and later Lucent, one of the successor firms left after AT&T broke itself into several pieces, supported industrial ecology through the appointment of research fellows at both large and small universities. Each appointment carried a small stipend for research. Lucent joined with the National Science Foundations to continue the research grant program but eventually stopped designating fellows. Although not universally accepted, the use of LCA is found in most well-established consumer products companies. The ISO 14000 environmental management standard contains a standard for LCA (ISO 14040–43). The Society of Environmental Toxicology and Chemistry (SETAC) has developed another, also widely accepted, framework. Supply chain protocols, now in place for many large products-oriented companies, frequently require that suppliers to these companies carry out LCAs. One can purchase a variety of software
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packages for LCAs. A new LCA coordination center has been started in the US. At a more strategic level, one can find several ‘proprietary’ systems in place. These include The Natural Step [14], Natural Capitalism [15], the McDonough and Braungart Scheme (‘‘Waste equals food’’) [24], and others. One of the four pillars of Natural Capitalism is ‘the flow economy’, a direct analog to an ecological network. This book has become one of the best selling volumes ever in the field of environment and sustainability. The Natural Step is based on a set of principles related to the ecological metaphor. The fundamental prescriptive basis of The Natural Step is the exhortation that human societies must close material cycles and prevent the accumulation of natural and manmade substances in the biosphere—the ecological system that supports all life. While none of these approaches come from activities strictly or historically located within industrial ecology (IE), all are based on or incorporate a set of strategic or design principles traceable to the ecological metaphor. In private conversations, I have been asked whether there is any difference between industrial ecology and programs like The Natural Step or parts of Natural Capitalism. These programs share the same ecological metaphor and focus on industrial production as part of their conceptual bases. They also incorporate prescriptive norms (for example, closed material loops), but offer different tools and structures of legitimacy. Industrial ecology comes from more academic roots, with its focus on analysis, for example, LCA or MFA. The Natural Step directs its prescriptions to the strategic level in firms and other organizations following a compass metaphor. Industrial ecology draws its legitimacy largely from academic sources. The Natural Step has attempted to become legitimated through a quasi-academic process in Sweden as well as popular support including that of the King of Sweden. Industrial ecology must expand its legitimacy beyond the academic world if it is to gain a foothold in other domains. From what little evidence can be found, it would appear that this key aspect of the institutionalization process has not occurred or is happening at a very slow pace. Most of the members of the new Society and almost all the papers submitted for presentation at the Inaugural Meeting have come from academia, with only a smattering from industry, government, or other sectors. 3.3. Government IE has also moved slowly in the government sector. But there are signs of embedding, especially in Europe, where a few of its basic concepts have been used as a basis of policy design. Extended producer responsibility (EPR) has become a part of EU policy as a framework
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for moving towards a closed-loop society. While also recognized as important in the US, EPR has not, however, made it into formal government policy. Chain management remains a facet of the emergent Integrated Product Policy in the EU. Material flow accounting is beginning to show up in the national statistical accounting practices of a few countries. A conference devoted to this subject was held in Sweden in the spring of 2001. An earlier OECD working group special session noted that ‘there are several uses of MFA that are relevant for decision-makers’ [25]. This set of practices, although not yet widely influencing the policy process, is being moved along by the formation of an international group of industrial ecology practitioners and economists from national bureaus that has convened several meetings and gathered around some common research themes. The USEPA convened a workshop in 2000 to examine the potential for industrial ecology in the US regulatory and environmental policy world. They maintain a small task force to track this subject. A set of strategies based on industrial ecology was included in the final report of President Clinton’s Commission for Sustainable Development [26]. The US National Science Foundation, as noted earlier, co-sponsored an industrial ecology research grants program for several years.
4. Conclusion The predominant work within industrial ecology to date has been based on the flow aspects of the ecological metaphor—LCA, MFA, exergy analysis, for example. Less has been done to explicate its structural or systems aspects such as interdependence, closedloop, community, or locality [27]. Studies of industrial complexes and of symbiosis (another ecological systems arrangement) are as yet at an early stage and have yet to receive the same scale of attention that the flow aspects have. One of the persistent unanswered questions about industrial ecology is whether these systems characteristics are normatively desirable. Another variant of Johansson’s question is, ‘‘Is it always a good idea to close loops or create an industrial symbiosis?’’ Much more research is needed to establish this aspect of the basic metaphor as paradigmatic, or, in a less sweeping claim, to delineate the bounds where the prescriptions derivable from industrial ecology hold true. If this does not happen, industrial ecology may become strongly criticized as mere ‘wishful thinking’, or perhaps in even stronger terms as intellectual dishonesty, for going beyond the scientific justification of a metaphor-in-use [3]. In a recent book, Consilience, E.O. Wilson argues for a coalescing of all of human knowledge into a unified whole [28]. Consilience is a rarely used word meaning a
jumping together. The idea suggests one potential goal for industrial ecology—to continue to draw in theorists and practitioners from many disciplines or fields that have become separated by the inexorable processes of modernist epistemology. In the sense of consilience, it will be very important to refine the language of industrial ecology and find a vocabulary in common with those working in other related ‘fields’ and practices that share all or parts of the metaphor. Whereas academic fields seem to proliferate unendingly, grounding new paradigms or routines in industrial practice is much more difficult. The relative pace of institutionalization between these two sectors bears this out. More work is demanded to demonstrate the benefits of bringing industrial ecology into the everyday world of business than is needed to support the creation of a new academic field. Business schools have been slow to pick up environment or sustainability as a legitimate area for research and teaching, and we can expect little attention to be paid to industrial ecology in the near term. The economics cultural base of most business schools produces blindness to the real links between business activities and the natural system of the Earth. The interdependent, community, systemsview of industrial ecology is more likely to be taken up by scholars nipping at the boundaries that now constitute business school curricula (and other fields as well). My own assessment of the near future for industrial ecology is positive. Evidence of unsustainability continues to grow in spite of efforts arising in every sector to turn the tide. Technological innovation still holds the high ground as the most promising potential path towards sustainability. But it is becoming evident that innovative processes for a sustainable future must depart from those of the past. It seems that ecoefficiency, the ubiquitous slogan of global industry, has a dark side. The so-called rebound effect, in which efficiency produces more consumer surplus, which then creates more consumption, may counterbalance much of the potential benefits of eco-efficiency. Perhaps the concepts of industrial ecology can guide innovation in a direction where the demands on the ecosystem continue to decline or are stabilized as more and more people on the Earth have their needs satisfied. As I noted earlier, while there is current criticism (which criticism is likely to continue into the future) about the scientific basis of the ecological metaphor, there is little or no argument that the industrial ecology metaphor can serve as a powerful tool to get the creative process going. And there is also little or no argument that such creativity is sorely needed to address the daunting problems facing both rich and poor, or industrialized and developing countries alike.
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References [1] Ehrenfeld JR. Journal of Cleaner Production 1997;5(1–2):87–95. [2] Ayres RU, Ayres LW, editors. A handbook of industrial ecology. Cheltenham (UK): Edward Elgar; 2002. [3] Johansson A. In: Ayres RU, Ayres LW, editors. A handbook of industrial ecology. Cheltenham (UK): Edward Elgar; 2002. [4] Kuhn T. The structure of scientific revolutions, 2nd ed., enlarged. Chicago: University of Chicago Press; 1970. [5] Ayres RU, Kneese AV. Production, consumption, and externalities. Washington (DC): Resources for the Future; 1969. [6] Ayres RU. In: Ausubel JH, Sladovich HE, editors. Technology and environment. Washington (DC): National Academy Press; 1989, p. 23–49. [7] Watanabe C. Industrial-ecology: introduction of ecology into industrial policy. Tokyo: Ministry of International Trade and Industry (MITI); 1972. [8] Billen G, Toussaint F, Peeters P, Sapir M, Steenhout A, Vanderborght J-P. L’e´cosyste`me belgique. Essai d’e´cologie industrielle. Brussels: Centre de Recherche et d’Information socio-politique (CRISP); 1983. [9] Frosch R, Gallopoulos N. Scientific American 1989;September:142–55. [10] Allenby BR, Cooper WE. Total Quality Environmental Management 1994;3(3):343–54. [11] Ayres RU, Simonis UE, editors. Industrial metabolism: restructuring for sustainable development. Tokyo: United Nations University Press; 1994. [12] Graedel T. Annual review of energy and the environment. Palo Alto (CA): Annual Reviews, Inc.; 1996, p. 69–98. [13] Ehrenfeld JR, Gertler N. Journal of Industrial Ecology 1997;1(1):67–79. [14] Isenmann R. Industrial ecology: paradigmatic shift of understanding nature. The 2002 International Sustainable Develop-
[15] [16]
[17] [18]
[19]
[20]
[21] [22] [23]
[24] [25] [26] [27] [28]
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ment Research Conference, Manchester, UK, April 8–9, 2002. Shipley (UK): ERP Environment; 2002, p. 261–702002, p. 261– 70. Commoner B. The closing circle: nature, man and technology. New York: Knopf; 1971. Ehrenfeld JR. Industrial ecology: a new framework for product and process design. Journal of Cleaner Production 1997;5(1–2): 87–95. Ehrenfeld JR. American Behavioral Scientist 2000;22(2): 229–244. Robe`rt K-H. The natural step: a framework for achieving sustainability in our organizationsInnovations in management series. Cambridge (MA): Pegasus Communications, Inc.; 1997. Hawken P, Lovins A, Lovins LH. Natural capitalism: creating the next industrial revolution. Boston: Little, Brown and Company; 1999. Matthews E, et al. The weight of nations: material outflows from industrial economies. Washington (DC): World Resources Institute; 2000. Guine´e JB, editor. Handbook on life cycle assessment. Dordrecht (The Netherlands): Kluwer Academic Publishers; 2002. Graedel TE, Allenby BR. Industrial ecology. Englewood Cliffs (NJ): Prentice Hall; 1995 [now in its second edition]. Duchin F, Lange G. The future of the environment: ecological economics and technological change. New York: Oxford University Press; 1994. McDonough W, Braungart M. Atlantic Monthly. 1998. Anonymous. Special Session on Material Flow Accounting, Chair’s Summary. OECD, Paris, October 24, 2000. Anonymous. Sustainable America: a new consensus. President’s Council on Sustainable Development, Washington, DC, 1996. Korhonen J. Journal of Cleaner Production 2001;9:253–9. Wilson EO. Consilience: the unity of science. New York: Knopf; 1998.