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Evaluating Ecological Impacts: A Conceptual Framework MILTON RUSSELL University of Tennessee and Oak Ridge National Laboratory Editors' Note: This chapter differs from most of the others in this boom It is, in essence, a personal essay prepared at our request by He author: It presents a particular perspective on the evaluation of ecological impacts. We found it very stimulating and hope our readers will fad it equal) so. A central thesis of ecology is that everything is connected to everything else; thus, any perturbation of an ecological system willican have effects that alter conditions for life of all other components of the system, and also redound upon the perturbing event itself. Some of these linkages may be strong; others weaL Some may attenuate quickly over space and time, as do ripples in a pool; others may amplify and spread, as does the triggering event for an avalanche. Human actions are among those perturbing events, and one of the reasons for the great interest in ecology is that it can provide useful insights into the fuller implications of human actions. Then, armed with greater understanding of these effects, decision makers can adjust behavior accordingly. They can seek to ameliorate or mitigate harmful effects or augment desirable ones. Note, however, that any influence on decisions of further insights on prospective outcomes depends not only on their size and nature. Outcomes will be serious or trivial, beneficial or harmful, or may just "be," depending on the values brought to the judgment, and on who is doing the judging. The purpose of this essay is to explore a basis on which these judgments might be made. The range of potential views is largein Chapter 4, Marek and Kassenberg provide a formulation vely different from that presented below. The literature is also enormous, composed as it is of much of what has been written on the place of man in nature. This essay surveys 31

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32 ECOLOGICAL RISKS neither that range of views nor that literature, but instead seeks to provide a sketch of an approach to valuing ecological change from a perspective that places humans at the center. Many may disagree with this formulation or find it too narrow or, at best, incomplete. However, this view deserves consideration if only because the humans who by action or inaction may alter the course of future events are the persons living now, and because the presumption that they seek to improve their welfare (defined broadly) rather than harm it seems reasonable. In the human-centered view explored in this essay, the ecological system and its natural components are treated as factors of production and elements in consumption, and are not presumed to possess value in and of themselves. Of course, humans may value natural systems for their own sake witness the affection for wilderness in the United Sates- and that fits well into the human-centered view. This essay knowingly avoids the more profound discussion of mankind as endogenous to natural systems and adopts an admittedly artificial division. Changes in the ecological system are judged by whether or not they add to or detract from the quality of life for the human population affected. Saying this, however, does not make decision processes much more straightforward. Key questions in valuing remain, some of which are identified below. A TYPOLOGY OF CONSEQUENCES OF CHANGE The discussion that follows starts by postulating an existing ecological situation, and then examines the major consequences to consider in deciding whether or not to change it. Such change could be of different sorts. For example, it could be to relieve existing stress on an ecological system by decreasing the amount of pollution that is affecting negatively some of its components. It could be to change relative species abundance through, for example, cultivating grasslands or logging forests. It could be to change the extent of human impact by enhancing access to a secluded area with a new road or, alternatively, by restricting it. It could be to dam a free-flowing river, or to drain and fill a swamp, or to convert wetlands to dry. Whatever the change, it will affect the ecological system and, in turn, those effects will impact humans in various ways. The first way in which humans will be affected is through changes in the magnitude of economic contribution from the ecological system. That economic contribution can take many forms. One form is the yield of materials desired by humans; these materials are counted as part of the Gross National Product (GNP). Forests provide timber and habitat for animals and plants of direct use to humans. Rivers, lakes, and oceans provide fish and birds that are important to diets. Grasslands provide grazing and hay for domestic animals and habitat for useful wild ones.

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ENVIRONMENTAL MANAGEMENT CONCEPTS 33 Cultivated acreage is also part of the ecological system. Shifts in its condition that affect output for example, due to pollution or to a change in population of beneficial insects flow immediately to the GNP. Indirect economic effects are also the consequence of changes affecting the ecological system. Change in cultivation patterns or amount or type of forest cover affect water flows with possible consequences of flooding, for example. These changed hydrologic patterns may require expenditures to onset an undesired effect, or they may have direct economic consequences through destruction of property. Wetlands have been shown to be efficient sinks for pollutants of various kinds, and their diminution may lead to de- clines in productivity of water bodies or to the need for capital expenditures to treat effluents or to prevent non-point pollution. Such indirect economic effects may or may not flow through the GNP, but in principle they are quantifiable and definable as factors in the overall output of the economy. Other factors are not as easily evaluated in the same way. These are the indirect amenity values of the environment which add or detract from human satisfaction. An obvious example is the value of the recreational opportunities presented by forests, streams, and oceans. Still less direct, but no less real, are the benefits received by people in viewing a pleasing natural vista, in seeing or listening to wild birds, or in viewing animals in the wild. Another effect felt by humans which must be considered here is the "existence value" which components of natural systems may have to those who never experience them directly. For example, many people would feel a deep sense of loss to hear that the giant panda of China or the elephant of Africa had been rendered extinct in the wild, even if they had never seen these animals there, nor expected to. Similarly, the non-fisherman may mourn the loss of a species from a river, or rejoice when salmon return to streams where they had been absent for a long time. This sense of responsibility and stewardship goes deep. It is not bounded by direct benefits or measured by an accountant's economic rationality. These values are difficult to measure as compared to, say, changes in the output of a fishery, but they have substantial importance where humans can express their interests in ecological outcomes. Ecological change caused by human activities characteristically leads to less diversity in systems, and hence to greater vulnerability in the pres- ence of shocks. Thus, monoculture increases the possibility of disastrous results from aberrant weather. Water control systems designed for 100-year floods can be overcome by 1,000-year episodes, with catastrophic results. Narrowed gene pools can leave important plant or animal populations susceptible to new disease. These risks are components of the human interest in ecological change which present misgivings, even when they are sufficiently vague as to defy explicit consideration.

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34 ECOLOGICAL RISKS Another risk factor is uncertainty, which comes in Ho forms. The first is lack of knowledge of what the second and higher order effects of a change will be, and how they will affect the human condition. The ecological havoc wrought by introduced plant and animal species are well known: rabbits in Australia; deer in New Zealand; the African bee in Latin America; the gypsy moth, English sparrow, and kudzu in the United States, to name a few. The harmful downstream effects of the Aswan Dam have been widely reported; some desertification in Africa and elsewhere has been traced to initially beneficial changes in agriculture practices. We have a tendency to remember the bad surprises and to ignore those which turned out well; for example, one can scarcely imagine agriculture without the massive exchange of plants and animals which has taken place. However, the point is that by definition there will be unforeseen effects, since those which are understood can be factored into a decision. Therefore, there will be an unquantifiable residuum of impacts for good or ill from any perturbation of an ecological system, and that fact alone offers reason for caution. The second form of uncertainty is in how affected factors will be valued in the future and under changed conditions. The point is obvious when it comes to plant and animal species rendered extinct; their potential uses will never be realized. This form of uncertainty also works the other way. Some dams built to produce electric power and to foster navigation in the United States now have lake recreation as their most important contribution to human welfare. Such unexpected results are not due to the failure to comprehend how the ecological system would respond to perturbation, but also due to changes in how much humans care about what happens. ISSUES IN EVALUATING CHANGES Consequences of ecosystem changes must be considered by decision makers when making social choices. How might the effect on "the quality of life for the affected human population" be determined, since it is often the presumed basis for the decision? Three issues come immediately to mind. The first is in the dimension of space what is the scope of the human community whose well being is to be considered? The second is in the dimension of time what consideration is to be given to those who will live in the future? The third is in whose wishes count how will different wishes be considered in reaching a social judgment? Take first the dimension of space. Ecological, economic, and social effects of a change may all attenuate rather quickly from the point of impact. When they do, the community affected is readily circumscribed and ejects upon it relatively easy to discover and describe. For example, a single, small river may be affected by acid mine drainage. Decisions may

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ENVIRONMENTAL MANAGEMENT CONCEPTS 35 still be controversial because their distributional effects are important, but the problem is at least not unmanageable due to failure of political and . . economic institutions to encompass all players. In other cases, all of the meaningful effects of a change may reside within the boundaries of a nation-state. The scope may be large and the facts less clear, but in principle the institutions would be in place to consider the interests of competing parties. In yet other circumstances, however, significant effects cross national boundaries. The harmful effects of acid rain are one example; the beneficial effects of actions to preserve tropical forests or to protect symbolically important animals such as the wild elephant are others. When ecological boundaries cross political ones, the potential lack of coincidence between the community with the ability to decide and the community that bears a share of the impact is clear. The human-centered, maximizing view would suggest that only those who share in both the ori- gin and the impact of the change would have their wishes fully reflected, although those wishes could include a measure of altruism. However, this does not doom those outside to having no possible voice in the final out- come. If the issue is important enough, they can either attempt to achieve an agreement more to their liking through recourse to a superordinate power, as with an international treaty (e.g., the Montreal Protocol on Ozone Depletiony, or seek to negotiate side payments or to offer threats that cause interests to coincide with effects (e.g., the proposed debt-for- forest swaps between parties in developed and in developing countries). In either case, interests are brought together albeit imperfectly because of the expense and difficulty of making bargains across institutional divisions. In doing so, evaluations of ecological effects by all those affected in the present are elicited, and in some way are the basis for action. EVALUATING FUTURE CONSEQUENCES The ecological effects of a human perturbation run forward in time as well as outward in space. They may attenuate readily: the fishery in the James River of Virginia recovered in a few years when paper and pulp pollution was controlled; and in just 50 years gross evidence of human habitation has disappeared in the Great Smoky Mountains National Park. On the other hand, effects may be as permanent as the extinction of a species or as near-irreversible as the desertification of portions of northwestern China, which occurred some 1,000 years ago. The evaluation of ecological change requires a decision as to whether persons in the near or distant future are to have their interests considered; if so, what those interests are; and finally, how those interests are going to be accommodated. Whether (and how) to account for the wishes of future generations

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36 ECOLOGICAL RISKS of humans is one of the most difficult conceptual problems in making decisions regarding environmental protection. At the limits the answer is easy: human society does value contributions to the welfare of future generations; but it does not care enough to embrace risk of its own suicide to contribute to that welfare. Away from these limits, however, no simple or absolute answers hold. And it is away from these limits that most important environmental questions exist. With regard to the second question of identifying the interests of future generations, the human-centered view suggests that they will be something like those of present generations, i.e., there will be concern both for narrow economic output and for the broader values of natural systems as described above. Consequently, one objective should be to endow subsequent generations with a combination of the undifferentiated ability to satisfy economic wants with actions taken to limit the diminution of the diversity of ecological systems. In achieving this, one approach is to assess future outcomes through the use of some positive discount rate. There are several possible value bases for applying this approach, but space permits discussion of only one. That basis would purport to leave an endowment no less rich than the one currently enjoyed. In that sense, future generations would be treated as if their wants had equal standing with present generations. One predicate of this approach is that resources not consumed in the present will accumulate at a positive rate to be the basis for future consumption, including environmental protection. From this it follows that it is neither necessary nor wise to invest as much today in preventing future harm as the projected cost of that harm to future generations. It is not necessary in meeting the equal endowment goal because, assuming the correct discount rate is chosen, future generations will be at least as rich as those living today due to the return from investment taking place in the present. They will be able to afford to take care of their problems as well as we can. It is similarly not wise. If investment in preventing future harm is not placed on the same discounted basis, as is investment in producing other goods and services, resources will be allocated inefficiently and total output will suffer. Future generations as they judge it will be worse off than they need to be. This is because by depleting resources to overcorrect problems now, we deny future generations the resources that could do the job at less sacrifice to them. This proposition has much to be said for it. In its most general form, it undergirds consumption and investment decisions of all modern economies. When it comes to ecological protection, however, caution should be exercised in its application. One critical assumption inherent in this approach is that resources are fungible, so that future wants can be satisfied by whatever set of resources

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ENY7RONME~^ ~AGEME~ CONCEPTS 37 exist then, as long as enough of them are available. This assumption is brought into question when it comes to ecological protection because of the irreversible nature of some changes. Extinct species cannot be brought back, however rich in other assets a future society may be. Their loss may be seen as an irremediable decrease in future welfare. On the other hand, it might be deemed presumptuous for us, today, to determine the pattern of consumption of those who live in the future. While they would thank us for leaving them "better off" in the abstract, their values may be such that they would not prefer what we prefer, given our life experiences. Some humility may be in order, for example, before we decide to save some species at high cost in future production ostensibly for the benefit of [mire generations. The fact that those in the future are our wards (in that they have a vital interest in decisions they can't affect) means that we bear an obligation to them. But it is not obvious that fulfilling that obligation requires handing on a specific endowment. Another assumption is that capital will continue to accumulate, or else that any future cataclysmic change would affect all capital equally. Human history has already provided evidence of wars and other events which have driven civilization backwards to greater reliance on natural systems, to a point from which progress could start anew. It could happen again. Perturbation of these systems to the detriment of their natural productivity may be of little consequence when man-made capital and technology are present to replace their output, but may be of an entirely different order of effect if the continuity of society is disrupted. For example, aquaculture may make natural fisheries unnecessary, but regrowth of a future civilization may be seriously handicapped if natural fisheries have been destroyed by pollution. Or, domestic hybrid animals and plants that are highly productive with intensive care may be unable to survive altered circumstances, and if native species are not available, there will be nothing on which people then living can depend. These elements are joined by the fact that the time scale for ecolog- ical change is so long that decisions taken today affect not just the next generation but potentially affect generations far into the future. With any positive discount rate, the implication is that any actions today are of little importance to the well-being of distant generations. While there may be something to be said for this view in some circumstances, when stated baldly it gives many people pause, especially when it comes to ecological change. A reasonable conclusion to be drawn from all this is that discounting is useful when assessing future effects, but only as a starting point. It must be used with caution and with full understanding of its assumptions and implications when long-term ecological change is at issue.

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38 ECOLOGICAL RISKS ECOLOGICAL VALUES AND OTHER VALUES This essay thus far has treated ecological changes and their effects on human welfare in isolation from the motivation that brings them about. That motivation includes increased economic production and resulting social change. In some cases, ecological perturbation is the direct and intended effect of actions to increase production. Dams are built to produce electric power and to prevent floods, and in the process drown valleys and change the flow of rivers. Swamps are drained and forests cleared to increase croplands. Noxious insects and animals are controlled to prevent disease and to lessen damage to economically valuable foodstuffs and materials. New species are introduced to yield higher returns. In other cases, ecological perturbation is the unintended consequence of actions pursued to increase production. Acid water is pumped from coal mines to free deeper seams for exploitation, but it changes the character of streams. Effluents from factories producing goods desired by people introduce chemicals into water bodies which can destroy living organisms or change their relative abundance. Waste heat from power plants changes the biota in the receiving water body, as does the effluent from domestic sewage treatment plants. Air emissions from coal combustion changes the pH of rain. Indeed, virtually all production and consumption has an unintended effect on surrounding ecosystems, sometimes positive but often negative. To avoid such effects, the activity must be eliminated or modified, and this has the first-order effect of decreasing the output of the economic goods sought. If the good is not produced or consumed, the resources devoted to it are available for transfer to an alternative use, but will produce output which by definition has lesser value or it would have been chosen in the first place. Alternately, the resources consumed in building and operating pollution control devices are not available to produce other desired goods and services. In short, avoiding or fostering ecological change has costs. The ques- tion in a human-centered value system is whether those costs are worth bearing. The easy answer is that it depends it depends on whether the total welfare is enhanced or reduced. This formulation gives the conse- quences of ecological change exactly the same standing as the benefits received from direct economic production. ~ade-offs among alternative ways of meeting human wants can be made and indeed must be made. Several cases may be distinguished when avoiding or fostering eco- logical change is contemplated. In some cases, the overall magnitude of economic output, even narrowly conceived, is increased. For example, the cost of reducing an effluent may be less than the added return from an

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ENVIRONMENTAL MANAGEMENT CONCEPTS 39 enhanced fishery. Different persons gain and lose, but the total economic product is increased. In other cases, the losses in output are more than made up by ecological contributions to health or welfare of the sorts de- saibed above as indirect economic impacts. In still other cases, the loss of direct output is more than offset when existence value, uncertainty, or fu- ture effects are considered. There is, of course, also the class of cases where the cost of reducing an environmental insult is greater than the benefits derived, even when the broadest definition of benefits is used. In this class of cases, no control action is justified when tested against human-centered criteria. Such a formulation of the structure of decisions gives rise to two problems. The first is identification of the boundaries within which the well-being of inhabitants are to be considered, a matter already discussed. Does this group only consist of persons within some political boundary and their heirs, or are the wishes of affected others to be considered? On the output side, the issue is similar. The second problem has to do with the distribution of gains and losses. Only rarely will these distributions be coincident; therefore, either action or inaction will leave some better off and others worse off, notwithstanding the question of whether the change in overall outcome is positive or negative. The fact that compensation of the losers by the winners may be possible does not, in the view of some, alter the case as long as all individuals themselves do not judge the outcome as satisfactory. How are these diverse views to be taken into account? And who decides? This intriguing and daunting question illuminates the complexity a social system faces in determining how to evaluate ecological impacts, and then in choosing what to do. This discussion has proceeded along only two dimensionsecological impacts and the sum of direct and indirect economic benefits, including such matters as existence values. However, the total decision matrix is far richer and other elements, including but not limited to distributional concerns, must be factored into any decision. FROM CONCEPT TO PRACTICE This essay has sought to describe a conceptual framework for how the products of ecological science might be used in making decisions that affect natural systems. The value system used on this essay puts human preferences at the center. This essay does not consider the difficulty of obtaining data necessary to make wise decisions. These data are almost always expensive to acquire, will remain incomplete, and will be subject to change. Hence, any decision will have an unknown and unknowable outcome. This fact suggests that a

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40 ECOLOGICAL RISKS premium should be placed on a decision that is robust in the presence of error, so that the possibility of irreversible damage is lessened. The framework presented has also leaped over the problem of iden- tifying human preferences, i.e., that set of outcomes which would indeed make people better off. The viewpoint is that of naive utilitarianism, with a benevolent entity seeking to maximize the sum of human welfare within a political boundary. That entity takes account of such matters as the distribution of benefits and costs. It takes an altruistic attitude towards those separated by space and time, but from the viewpoint of an outsider, not a participant. Actually, the difficulty in doing this through any sort of political process is great enough when a circumscribed population is considered. It becomes greater still when small effects on large numbers of far-distant persons are considered. Thus, when concern for the values of future generations are taken into account, the matter becomes, strictly speaking, unknowable. Even when objective outcomes are assumed to be known, how they are valued by people, much less how to aggregate those values, remains a serious problem. The point is that the results of ecological understanding can inform decisions, but such understanding alone cannot dictate them. Ultimately, those decisions rest on the values of the persons making them. Ecology's job is to make sure that the full consequences of alternative decisions are illuminated. Some of the ways in which such knowledge could be used, and in fact is essential, have been outlined here. It is the premise of this essay that the task of malting ecological insights available to decision makers is of service whatever the value system used for final decisions. RELATED READINGS Brundtland, G.H. 1987. Our common future. Report of the World Commission on Environ- ment and Development. Oxford: Oxford University Press. Dubos, Rene. 1980. The wooing of earth. New York: Charles Scribner's Sons. Hardin, G., and J. Baden, eds. 1977. Managing the commons. San Francisco: W.H. Freeman and Co. MacLean, D., ed. 1986. Values at risk. Totowa, New Jersey: Rowman and Allenheld. Partridge, E., ed. 1981. Responsibilities to future generations: Environmental ethics. Buffalo, New York: Prometheus Books. Sagoff, M. 1988. Ike economy of the earth: Philosophy, law, and the environment. Cambridge: Cambridge University Press. Stokey, E., and R.Z Larsen. 1978. A primer for policy analysis. New York: W.W. Norton.