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Technological Trajectones and the Human Environment. 1997. Pp. 157-167. Washington, DC: National Academy Press. Toward the End of Waste: Reflections on a New Ecology of Industry ROBERT A. FROSClI I want to think simply and abstractly about all of industry, considered as a single block. That block takes in materials and energy, transforms them into products and wastes, and then excretes the products and wastes. At the end of their useful lives, the products may become wastes and may also be excreted, that is, "disposed of" as waste. Increasingly, we are concerned with decreasing the amount of waste to be "disposed of," and thus with changing the nature of manufacturing processes and products. In this essay I will rethink the ecology of industry as a problem in the present and will ponder the future flows of materials within and among industries. Where might we try to go? How might we try to get there? By any measure, wastes abound in modern economies (see Wernick et al., this volume). In the United States, the material wastes from manufacturing, min- ing, oil and gas extraction, energy generation, and other industries currently are on the order of ten billion metric tons per year, though a large fraction of this is water. US air emissions of materials, such as the carbon in carbon dioxide, are approximately two billion metric tons per year. The end products of industry annually turn into about two hundred million tons of municipal solid waste in the United States.~ Traditionally, waste is whatever material is left, to be disposed of later. The emerging field of industrial ecology shifts our perspective away from the choos- ing of product designs and manufacturing processes independent of the problems of waste. In the newly developing view, the product and process designers try to incorporate the prevention of potential waste problems into the design process (see Frosch, 1992, 1994, 1995~. Industrial ecology notes that in natural ecological 157
158 ROBERTA. FROSCH systems organisms tend to evolve so that they can use any available source of useful materials or energy, dead or alive, as their food, and thus materials and energy tend to be recycled in a natural food web. Even with the design of products and manufacturing systems to minimize waste, some waste energy and material, whether from manufacturing or from products at the end of their useful lives, will be inevitable. The second law of thermodynamics (in the simplest of terms, the impossibility of converting all the heat from a reservoir of energy into useful work) insures that there will at least be waste energy from a process; waste energy frequently appears as waste material, or it may be carried away as heat in a material. We do not know how to design processes that are perfectly economical with materials, and, in any case, this may be impossible to do. Nevertheless, the idea of industrial ecology is that former waste materials, rather than being automatically sent for disposal, should be regarded as raw materials useful sources of materials and energy for other industrial processes and products. Waste should be regarded more as a by-product than as waste. Indeed, as part of the design process for manufacturing end products, wastes might be designed to be useful by-products. The design optimization process would include the generation of waste, the design of waste, and the cost conse- quences of alternatives, for example, in reuse or disposal. This practice occurs in some parts of some industries but is not widespread. The overall idea is to consider how the industrial system might evolve in the direction of an interconnected food web, analogous to the natural system, so that waste minimization becomes a property of the industrial system even when it is not completely a property of an individual process, plant, or industry. I will approach the problem by trying first to abstract the essence of indus- trial systems in an ecological sense, subsequently considering how we might characterize and graph future states of industrial ecosystems. Next I will contem- plate the potential fates for wastes and how they might be balanced. Then I will look at some of the evolutionary trends of industrial ecosystems and the proper- ties that might mark or lead to attractive states. Finally, I will examine how we might choose policies that are likely to lead toward attractive outcomes. My approach is not to forecast but to postulate future states and sets of states, inquir- ing as to how they might be reached via attractive, or at least tolerable, routes. I am thinking about coupled states of industry and the environment external to industry; my scale is industry, society, and the world. When I use "we," I mean "we, the society," in whatever way a social decision may be reached to do, or not to do, something technically attractive. ABSTRACTING THE INDUSTRIAL SYSTEM Let us consider industry, indeed, the whole of humanity and nature, as a system of temporary stocks and flows of material and energy. Materials are seen
REFLECTIONS ON A NEW ECOLOGY OF INDUSTRY 159 as what they fundamentally are: elements (atoms) in the sense of the periodic table, compounds (in the sense of atoms bound together into molecules by energy embodied in chemical bonds), or mixtures of elements and compounds (perhaps several of each). In this sense, everything is a dance of elements and energy. For this discussion, energy is considered at the chemical but not the nuclear level; elements remain the elements that they are. For example, plastics polymers- are seen less as specific materials than as collections of carbon atoms, hydrogen atoms, and some others (for example, nitrogen, oxygen, and chlorine) bound together by the energy of chemical bonds. The processes of industry re-sort atoms into various collections or mixtures of elements bound by energy. Every step in manufacturing product creation, product use, and product disposal is a more or less transient event, a temporary (possibly long-lived, but temporary) use of some set of atoms and energy. (We hark back to the world of Democritus and Lucretius!) In this sense, products are just way stations in the flow of materials and energy a temporary storage of elements and bond energy. Thus the whole sequence of events from mining or extraction to disposal is seen as a sequence of rearrangements of elements and energy. From this point of view, reuse of materials produced as "wastes" in the course of production, or as "wastes" at the end of product life, is only another re- sorting of the elements and energy. The point is trivial, but the general way it puts all parts of the process into the same simple framework may suggest some useful lines of thought. Clearly, the roles of energy and energy cost determine what may be done. Energy binds materials into compounds, but energy may also be used to take compounds apart. Energy is required to drive the processes of negentropy (i.e., those that increase order or pattern, particularly those with value to humans) that separate mixtures back into the elements and compounds from which they were mixed or that assemble atoms that have been distributed in a diluted way into collections of compounds (molecules) or other atoms. Thus, the availability and cost of energy will fundamentally determine which of these processes is eco- nomically useful for transformations and when. At each stage in a process that produces "product" and "waste," we have some choices that determine the material forms of each, and we may link the series of choices with later sets. We postulate a universe of material/energy paths through the production, life, and dissolution of any product or set of products. We can also consider each path to be a sequence of transformations from one mate- rial/energy embodiment to another. (I generalize on a larger scale the chemical engineer's view of life.) We can view the whole of material industry as a network of such paths or transformations, connected at each end (extraction of materials and disposal of products) to the environment external to the process and product, and at places in the middle (disposal of incidental waste).
160 ROBERTA. FROSCH PLOTTING STATES OF THE INDUSTRIAL SYSTEM Each network of paths or transformations may be considered a "state" of industry. Given some idea of impacts and costs of alternative paths, we could, in principle, choose among them. We would need somehow to rate the environmen- tal impact of so complex a thing as the total industrial system. For purposes of this general discussion, I will assume that we can rate total environmental impact, and we will use only one measure or graphical axis to do so. I also assume that cost needs only one measure or axis. Cost implies dollars, but it should really be thought of as cost in the most general sense: total effort, including capital, work, energy, economic opportunity costs, and all other forms of effort, somehow calibrated in dollars. To help choose we might then create a two-dimensional graph of these states of industry by plotting cost versus environmental impact, placing each alternative state in its appropriate position. With only one cost and impact for each state, I am implicitly considering only the total social economic cost and the total environmental cost without examining the question: Upon whom do the elements of cost and impact fall? Alternatively, we could struggle with a multidimensional space in which many axes represent different kinds of environmental impact, various kinds of costs attributed to different actors, and political and cultural variables. Such a multidi- mensional approach could, in principle, take account of regional differences, local politics, and other concerns. For the immediate purpose, however, I will continue to illustrate the ideas with the two dimensions of environmental impact and cost. We must then ask about objectives. In particular, what principles should we use to choose preferred states, representing networks of paths through the se- quence of material transformations? We can visualize the two-dimensional graph in which each state appears as a point, resulting in a cloud of points. Given the usual uncertainties in impact assessment and cost estimation, the "points" could represent statistical haloes, but at this level of generality, visualizing points is fine. I presume we would like to choose among states as close to the origin as possible: least cost for least impact. Various states will in fact apportion the costs and impacts to different actors, but if we were to work outward from the origin, we would be looking for solutions that are "optimum" in some useful sense, even including the politics of choosing among states near the origin on the basis of where the costs and impacts fall. However, a moment's thought about the multi- dimensional, more realistic possibilities and the uncertainty haloes of the points would reveal that detailed optimizing principles are far from obvious. For some given scenarios of industrial technology and industrial organiza- tion, we might expect the possible states, the points on the graph, to have some systematic relationship or lie on a curve. For example, I would expect the attain- ment of extraordinarily low levels of total industrial waste or "zero waste" to be very expensive for industry; extremes are frequently costly to attain. Symmetri
REFLECTIONS ON A NEW ECOLOGY OF INDUSTRY 161 cally, absent internalization of environmental impact costs, simply "throwing away" wastes might be expected to have high impact and low cost to industry, so these state points would be in that region of the graph. A standard economic interpretation might expect the curve connecting possible states of similar tech- nology and industrial organization to be hyperbolic in character, like a standard demand curve. In that sense, the graph of effort versus impact can be thought of as a conventional tool of the economist. FATES FOR WASTES To find future states desirably located near the origin of the graph, it seems reasonable to examine those that imply both the minimization of waste in the production process and the use of wastes from various production processes across industry as input materials. Finally, we would search for "best" states by some optimization process that simultaneously considers total cost and impact. This leads us to a scenario or, rather, a set of scenarios. Let us assume that manufacturers do an excellent job of minimizing process waste under some set of economic and regulatory pressures. Some process waste will still remain to be dealt with, as will materials available as "waste" from products arriving at the end of their useful lives. Therefore, as a baseline, let us assume a future state in which an "optimum" overall balance has been struck between limiting the creation of waste during production and reusing "wastes" that are produced as raw materials in other productive processes or that result from products at the end of their lives. This "optimum" has been chosen to lead to a minimum amount of total waste impact on the environment at minimum total cost. Some waste remains with which the overall system must deal. The scenario must employ some policy for dealing with the remaining waste. The current policy, generally speaking, is to dispose of it: destroy it, if chemical (i.e., take it apart into simpler compounds or into elements), or "bury" it. In the general spirit of provisioning for the long run, waste for which no immediate reuse possibility exists could be stored against future need. Suppose we consider so-called Superfund sites that are "contaminated" with hazardous materials to be "filing cabinets" for potentially useful materials. Would this approach cost less or more than the current sites or systems for "disposal"? The care of potentially valuable materials may be more economical than their "disposal." Such a shift in how we view "waste sites" would require more thoughtful characterization and labeling of wastes and perhaps better technologies for packaging them. Filing cabinet storage makes sense for many elements, particularly those with volatile market prices, and for compounds that involve elements (particu- larly metals) that are likely to be of future use. What to do with organic materials lacking an immediate prospect of reuse is less clear. For many such materials, storage against later reuse as chemical feedstocks might be sensible. For ex- ample, pesticides are complex organic chemicals. In the spirit of petrochemical
162 ROBERTA. FROSCH cracking and transformation of crude oil, such a mix of organic chemicals might be a good feedstock from which to extract energy and/or derive simpler com- pounds suitable for chemical synthesis. Excess bond energy might be available to help power the cracking process. However, the variable stream of available wastes might make it hard to maintain a stable process. The technical challenge is then to design chemical processing systems taking into account significant variability in the stream of input materials. Many materials might be more beneficial only as sources of energy the energy embodied and stored in their chemical bonds. The extraction of this bond energy should be viewed as a matter of chemical processing, not just burning, and therefore as requiring the same level of process control as other chemical pro- cessing. Such control has not always been practiced with "burning" to get the chemical energy back. Incineration without energy generation as part of the process seems silly unless it is clear that the price of the power and the avoided costs of other disposal of the material do not amortize the costs of adding power generation equipment and its operation to the incinerator. The "cogeneration" alternative clearly becomes more attractive if the price of energy rises. TRENDS AND PROPERTIES The state described above might not cost the minimum; other states nearby in the imaginary graph might achieve nearly similar impacts for a lower total eco- nomic cost to society, presumably with a different distribution of costs among the players. Even in a highly abstract and simplified picture we see complex possi- bilities for choice. If we go again to more dimensions, in which various kinds of environmental and other impacts and various kinds of costs appear as axes of the display, the problem is yet harder. Before discussing the postulated state further, some other states with resem- blance to it bear description. These may or may not be in the same part of the graph with regard to costs and impacts. An earlier state from our industrial/ environmental history may be described as one in which direct manufacturing costs were minimized as a way of minimizing product cost, but environmental impacts were generally regarded as external to the industry. We have recently been in a state in which direct manufacturing costs are minimized, but regulation and, increasingly, social obligation require industry to take responsibility for disposal of waste in a way that has a low environmental impact. We now see demand for movement towards a state in which manufacturing combines cost minimization with low or zero production of waste. The historical sequence implies next the state in which waste production during manufacturing is combined with the reuse of wastes within industry, as is the possibility of varying the materials in a product and the processes of produc- tion in order to change the nature of the waste materials, making them easier for someone to use as process input materials. Incomplete consumption of material
REFLECTIONS ON A NEW ECOLOGY OF INDUSTRY 163 in manufacturing and reuse is also implied, therefore leaving some waste to be disposed of at some cost. The popular term "sustainability" presumably implies maintaining the global stock of available materials for as long as possible while at the same time preserv- ing the general environment in a livable condition for as long as possible.2 This latter condition should hold true for disposal and storage as well. The availability of materials implies the small disposal that is, the reuse- of elements that have limited availability. For this exercise I consider only Earth as available. If we make the rest of the solar system or the rest of the universe available, the principle remains the same, but the numbers and time scales change. Preserving the environment for as long as possible against poisoning by the disposal of materials would require that we not disperse materials that harm the environment, even in concentrations so low as to not seem troublesome. Dis- persal at the level of one part in a million, if continued for a thousand years, can dangerously accumulate to one part in a thousand. Although this principle omits the question of the economics, choices, and technology of future generations, it does suggest that good technologies for generating negentropy at the lowest possible direct energy cost would be welcome. Although the second law of ther- modynamics tells us what the lowest energy cost must be, it does not prevent us from using technologies in which part or all of the energy cost is "free" to us, that is, where energy is used that is not otherwise directly available to us or used by us. Solar energy can be such a source. So can some or all of the energy used by organisms for example, microorganisms, because they may extract energy from sources we do not use provided we can figure out how to have them be our collectors. These considerations suggest that, in general, producing concentrated wastes that could be useful as someone else's raw material is likely to be more interest- ing in the postulated state than producing diluted wastes. This finding reverses the wisdom with which sanitary engineers began the twentieth century, "The solution to pollution is dilution." However, it also suggests that a weakness of the alternative industrial ecosystems that include the idea of "produce but reuse" may be the small fugitive spills and emissions over long periods of time. Such a state is likely to require ever-better technology and practices for control. Let us discuss some of the other properties of the industrial system that we have developed as our example. It will require a fairly widespread, large-scale, market-enabling information system to describe those materials available for immediate purchase or delivery and those that may be contracted for on a longer- term basis. Information on potential receivers, or buyers, of particular materials will also be needed. I am unaware of any publication, comparable to the weekly slick-paper tabloid Chemical Marketing Weekly, that specializes in chemical wastes, although that publication probably does include some materials that origi- nate as wastes. Beyond straightforward information leading to direct transfers of material,
64 ROBERTA. FROSCH perhaps through brokers of materials, the brokering of more detailed adjustment possibilities would be needed. Adjustments in the products or processes of pos- sible suppliers or users might generate "wastes" for manufacturing systems de- signed to use them. This process must occur for the production of particular materials now, but not much seems to happen to adjust wastes. Specialized open-market commodity exchanges of the "pit" kind might de- velop in waste commodities. A computer net exchange system now reportedly operates among dealers in used auto parts, and this concept might be extended to other "waste" materials. More generally, the Internet portends cheap ways to link otherwise unconnected buyers and sellers to create markets and to search large, poorly structured databases for highly specific items. To work for the reuse of significant quantities of materials, the system would have to be based upon realistic economics, in which the alternative processes and product materials of buyers and sellers made financial sense, including process and product costs, information and transportation costs of the various alterna- tives, and possible final disposal costs, whether by alteration or "land-filing." For some materials lacking realistic alternative uses, fresh incentives might make recycling economically viable. These could take forms such as taxes on their disposal in order to force reuse to be economical. The idea is that for some necessary materials, the least environmental impact might occur when a limited supply of them circulated, as opposed to flowing them through the system to "disposal." In cases where "waste" material had no immediate use or was not available in sufficient quantity for an immediate buyer, useable public information on the contents of the filing system in landfills, with realistic systems of storage and retrieval costs, would need to be maintained. Thus, as materials came into mar- ketable value, as happens today with copper scrap for smelter material as the market price varies, their availability would easily be known, and they could reenter the active materials market. Both the transportation and the filing-cabinet storage systems will require considerable attention to safety, and the resulting costs would automatically be part of the trading system. Such a system would likely require a new kind of regulation for waste and hazardous-waste materials, one that recognized move- ment and disposal by use in an industrial process as equivalent to what is now considered final disposal. In fact, it might have to be more definitive than current regulations, which seem to view nothing as final disposal. In addition, the current tendency towards an infinite chain of liability in which no one's liability seems to be transferable with the material, and in which liability does not die, even when the material is transformed into something else might need somehow to be altered. The new state of the industrial ecosystem that I have described assumes a reasonable supply of waste material even after a mature system of waste preven- tion is developed in the manufacturing industry. Many materials will not be
REFLECTIONS ON A NEW ECOLOGY OF INDUSTRY 165 internally reprocessed for reuse by the manufacturer because, for example, it may make no sense for a hard-goods manufacturer also to be a metal smelter or a maker of polymers feedstock. Waste material from sheet metal and semifabricated metal parts manufacturing will also remain available as material to be repro- cessed. Not everything will be amenable to internal reprocessing. CHOOSING POLICIES How can we decide which policies are likely to lead in the right direction where the end states reached would be "good" and well chosen? Nearby states are likely to resemble the state I have postulated, differing perhaps in the proportions of waste minimization and reuse, or in the specific configuration of the industrial networks, which nevertheless all have roughly the same amount of material re- use. Other states may differ in their network properties, or represent different kinds of environmental impact making up the same or a different, quantitative index of total impact, or represent different total societal costs or allocation of costs to different actors. We must keep in mind that policies will not lead to a particular chosen state. The model of the future will be too crude, and systems do not respond by behav- ing exactly as policymakers desire. Actors in the system respond by doing what is in their interest, or what they perceive to be in their interest, so while systems move in a direction that the policies help determine, they tend toward being pushed in the direction of a family of possible future states rather than to some specific state determined by the set policy. We need some process for deciding which policies are likely to push the system in the direction of a set of states that would be desirable or contain mostly states that are desirable or at least accept- able. A procedure that might work in principle would be to sample the graph of states, looking for those that are considered desirable or acceptable in terms of their position in relation to the cost/impact axes. Perhaps, if we are ambitious, we might look for states that are desirable or acceptable in terms of the finer structure belonging to other axes that we collapsed into our overall indices of cost and impact; these might include regional differences, assignment of cost to other actors, and political differences. Given that we find a set we like, we would then consider the set of policy initiatives most likely to move industry in the direction of each state. Especially interesting are the families of policies that are common to moving in the direction of various kinds of states that are desirable or acceptable, policies that also do not appear likely to push industry in the direction of undesirable sets. My model for policy choice among industrial ecosystems is statistical me- chanics, which has developed very successfully to study systems consisting of a large number of interacting elements particularly systems in which the large 1.
66 ROBERTA. FROSCH number of elements and possible interactions present an otherwise almost insu- perable challenge to understanding the behavior of the whole system. Technical questions abound about this scheme, for example, about the rela- tionship of families of policies to the resulting state sets to which they lead; about the degree to which simple measures of state desirability reasonably represent the complexity of real world variables; and about whether the policy sets leading to generally desirable states as described by the simple measures remain robust in the face of the underlying complexity. In looking at such policy choices and deciding whether they push the right way, discussions must also examine some of the ways in which a policy set might perversely or unexpectedly push industry towards undesirable states. The way of arriving at end states need not be by a process of long-term governmental, or large-scale, collective, detailed planning and detailed regula- tion. My interest is in defining states and looking at policies that may foster a move in their direction, not an attempt to get to them by compulsion. I have emphasized provision of information, freedom to contract, and profitable com- mitments. Experience suggests that systems with multiple tight connections between many elements tend to be brittle and easily become unstable if a few links are broken or a single actor is removed. Systems with loose connections are much more robust, especially if the network is of single and no more than double connections. The intention here is to suggest a direction for industrial develop- ment that would be realized by standard market mechanisms with the usual relatively loose, two-party network of connections or transactions. If this devel- opment is achievable, the issue of special brittleness of the new system need not arise to any greater degree than it customarily appears in any set of market relationships of manufacturers, suppliers, and customers. Clearly, the issue of robustness would need to be considered as a new system begins to develop. CODA I have sought to suggest a framework for thinking about materials and their flows in the context of industrial waste, about the balancing of costs and environ- mental impacts in possible future states of industry, and about a method of policy examination. I feel that this approach, while abstract, contains elements that make further discussion and elaboration of its possibilities worthwhile. I believe that ten billion or so healthy people cannot prosper on Earth without a manufacturing industry and large, complex materials flows. A simple agrarian society will not be efficient or effective enough to support likely future human numbers. Yet, vast reductions in waste seem possible if we begin to reconceive the ways we understand and operate industrial ecosystems. Jumping at solutions to particular environmental problems as they arise is easy but has not carried us nearly far enough. Little effort seems to have been given to the general, long
REFLECTIONS ON A NEW ECOLOGY OF IND USTRY 167 term, large-scale global waste problem in an analytical way. We need to stimulate more such thought. ACKNOWLEDGMENT I am indebted to numerous colleagues for discussions over the past several years, but would like to mention, in particular and alphabetically, Traded Allenby, Jesse Ausubel, Robert Ayres, William Clark, Nicholas Gallopoulos, Deanna Richards, and Walter Stahel. NOTES 1. Energy wastes are also huge. Even in the most efficient economies, perhaps 10 percent of the energy extracted and generated from primary sources actually serves the end user. On the connec- tion between material and energy wastes, see Nakicenovic (this volume). 2. For a general discussion of the meaning of sustainability, see Solow (1993) and Starr (this volume). REFERENCES Frosch, R. A. 1992. Industrial ecology: A philosophical introduction. Proceedings of the National Academy of Sciences of the United States of America 89:800-803. Frosch, R. A. 1994. Industrial ecology: Minimizing the impact of industrial waste. Physics Today 47(11):63-68. Frosch, R. A. 1995. Industrial ecology: Adapting technology for a sustainable world. Environment 37(10): 15-24,34-37. Solow, R. M. 1993. An almost practical step toward sustainability. Resources Policy 19(3):162- 172.
