SCOPE 5 - Environmental Impact Assessment
What is the Problem?
1.1 DEFINITIONS 1.2 THE ENVIRONMENTAL IMPACTS OF HUMAN ACTIONS 1.2.1 Environmental Changes: Natural and Man-Made 1.2.2 Environmental Impacts and the Stage of Technological Development 1.2.3 Some Examples from Developing Countries 1.2.4 Some Examples from Industrialized Countries 1.3 RESPONSES OF SOCIETY TO THESE ENVIRONMENTAL CHANGES 1.4 THE SCALES OF INTEREST IN ENVIRONMENTAL IMPACT ASSESSMENTS 1.5 BIOGEOPHYSICAL AND SOCIOECONOMIC IMPACTS 1.6 THE PREDICTION PROBLEM
This book is about environmental impact assessment, which is defined as an activity designed to identify and predict the impact on the biogeophysical environment and on man 's health and well-being of legislative proposals, policies, programmes, projects, and operational procedures, and to interpret and communicate information about the impacts.
A number of terms have been used in English-speaking countries to distinguish (a) between natural and man-made environmental changes; and (b) between changes and the harmful and/or beneficial consequences of such changes. In one approach, a man-induced change is called an 'effect', while the harmful and/or beneficial consequences are called 'impacts'. Sometimes, of course, an impact could be beneficial to some citizens but harmful to others. Another convention is to use the term 'impact' to denote only harmful effects. In still other countries, the words 'effects' and 'impacts' are synonymous and deleterious effects are termed 'damage'. No matter how the words are defined, however, a change/effect/impact is usually given in terms of its nature, its magnitude, and often its significance.
In the following chapters, the distinction will be maintained that a 'change' can be natural and/or man-induced, that an 'effect' is a man-induced change, and that an 'impact' includes a value judgement of the significance of an effect. However, there is no objection to other terminologies.
Hereafter the acronym EIA will be used for the phrase environmental impact assessment.
1.2 THE ENVIRONMENTAL IMPACTS OF HUMAN ACTIONS
1.2.1 Environmental Changes: Natural and Man-Made
Even in the absence of man, the natural environment undergoes continual change. This may be on a time-scale of hundreds of millions of years, as with continental drift and mountain-building, on a time-scale of tens of thousands of years, as with the recent Ice Ages and the changes in sea level that accompanied them, on a scale of hundreds of years, as with the natural eutrophication and siltation of shallow lakes, or over a period of a few years, as when a colony of beavers rapidly transforms dry land into swamp. Some of these natural changes are irreversible (e.g., eutrophication of a lake), while others are cyclic (e.g., the annual climatic cycle) or transient (i.e., droughts).
Superimposed on natural environmental changes are those produced by man. Even as a hunter-gatherer, man's use of fire modified some natural environments. Then with the domestication of animals and the introduction of agriculture, the effects of his actions became more widespread, especially as large human settlements came into being. The rate increased with the development of industry as muscle power was replaced by energy derived from fossil fuels, until during the last few decades human impacts have reached an unprecedented intensity and affect the whole world, due to a vastly increased population and higher consumption per head.
Man's increasing 'control' of his environment often creates conflicts between human goals and natural processes. In order to achieve greater yields or for other purposes, man deflects the natural flows of energy, by-passes natural processes, severs food chains, simplifies ecosystems, and uses large energy subsidies to maintain delicate artificial equilibria. In some cases, of course, these activities may create surroundings that man considers desirable, as, for example, aspects of the European countryside, which reflect careful husbandry during many generations. Nevertheless, conflicts often arise between strategies that maximize short-term gains (e.g., five-year yields of food) and those that maximize long-term benefits (e.g., 50-year sustained yields). The former sometimes require a penalty of irreversible environmental degradation. Disagreements between economists and ecologists hinge largely on their differing perspectives of time; in general, 5-10 years is considered to be a long period by economists but a short period by ecologists. Little account is taken in economic calculations of, for example, slow soil deterioration, depletion of an aquifer, or accelerated eutrophication of large water bodies. The practice of discounting as an economic tool can unduly focus attention on the short term.
Because natural biogeophysical environments fluctuate with time, we are unable easily to distinguish changes brought about by man. Take, for example, the built-up area for a new settlement which is being sited, as is often the case, on complex terrain. This is likely to change the physical environment in many ways. But, in order to understand these changes, it is necessary to know what the conditions would have been like if no development had taken place. It is not easy to measure exactly the present condition, far less to assess the significance of past trends and to project these accurately into the future. In Appendix 1, the problems associated with data gathering and interpretation are considered.
1.2.2 Environmental Impacts and the Stage of Technological Development
Perceptions about environmental impacts can be rather different in different countries. Where poverty is widespread and large numbers of people do not have adequate food, shelter, health care, education, and old age security, the lack of development may constitute a greater aggregate degradation to life quality than do the environmental impacts of development. The imperative for development to remedy these defects may be so great that consequent environmental degradation may be tolerated. The grinding and pervasive poverty in the underdeveloped nations has been spoken of as the 'pollution of poverty', while the widespread social and environmental erosion in the developed nations has been characterized in its advanced state as the 'pollution of affluence'. While it is clear that decisions will and should be made based upon different value judgements concerning the net cost-benefit assessments about environmental, economic, and social impacts, it is now widely accepted that development can be planned to make best use of environmental resources and to avoid degradation. The process of EIA forms a part of the planning of such environmentally sound development.
In developing countries an especial challenge is to stimulate development processes at the local level. If such a process can be inaugurated broadly, the fruits of development may reach more of the segments of the population than do the large, centralized schemes. Better adapted development projects and programmes are apt to engender broader public support and cause less undesirable social displacement than a few large centralized projects. Where the development processes can be focused on programmes that can be sustained in large part with renewable local resources and broad public support, this is to be encouraged.
The emerging recognition that local sources of energy can be better utilized, that materials can be recycled more effectively, and that some pollution problems can be alleviated or largely avoided by prudent, locally scaled activity forms a basis for encouraging wider use of such objectives in development activities, both in industrialized and developing nations. The term 'ecodevelopment' has been used to describe this approach (UNEP, 1973, pp. 135-137). The success of environmentally sound development depends on proper understanding of social needs and opportunities and of environmental characteristics. For this reason, some form of EIA is appropriate to local development as well as to large centralized projects.
1.2.3 Some Examples from Developing Countries
It is clear that each region and local area should make the best use of land and other natural resources, without causing damage or deterioration by, for example, laterization, erosion, desertification, or the spread of water-borne diseases like typhoid fever, dysentery , schistosomiasis, and hepatitis. Shifting cultivation, which is a common practice in many parts of the humid tropics, may be used as an illustration. This practice is ecologically acceptable whenever it allows adequate time for the forest regeneration cycle, permitting the maintenance of soil fertility. In the past, natural factors (cultural taboos, traditional ways of life, disease, and wars) kept the system in balance. However, with modern medicine and new social values, the rate of population growth has increased, the ratios of land area to population have decreased, and the original balance has been disturbed to such an extent that the cycle of cultivation does not allow for proper restoration of soil fertility. In many cases, there is not even a recovery period, and extensive areas have become overgrown with secondary vegetation and have become unsuitable for agriculture.
Failure to take account of social structure may also have implications which are of major significance. These effects may be manifest in several ways. The maintenance of particular institutions and traditions is dependent upon the life style of a community, and once that life style is changed, for example by a resettlement programme, the prevailing social organization will be undermined and traditions will be lost. If a community continues some of its long-standing activities after development, the viability of a project may be affected. Certain types of traditional agricultural practice may adversely affect agricultural development, for example, by inducing soil erosion with a consequent loss of production. Finally, development may lead to the adoption of new life styles which generate social stress or have major impacts on the environment. For example, 'advanced' agricultural techniques utilizing high-yielding cereals and energy subsidies have disrupted traditional village structure because of changes in the distribution of wealth and the value patterns. The people thus displaced have migrated from the villages into urban slums or into the hills. In the cities, the immigrants have magnified the problems of waste disposal, water supply, housing shortages, and unemployment. In the hills, they have cut the forest to harvest and sell the wood and to clear new land for cultivation; these marginal lands, on steep slopes, have been cultivated without regard for soil conservation techniques, and rapid erosion threatens even their limited productivity; in addition, associated changes in water-flow and siltation rates endanger the continued usefulness of dams constructed in these watersheds (Soemarwoto, 1974).
Environmental problems in the developing world are clearly linked to unbalanced development. This is why EIA, as a component of sound development planning, is particularly important there. But these countries face a dilemma. Their need for environmental change is very great. Their resources of trained scientists to participate in environmental surveys and impact assessments are very slender. And a lack of finance, training, and infrastructure may restrict the development modes open to them. The simple transfer of the technologies now employed in the developed nations _ including their methods of environmental impact assessment _ may not be the best way to alleviate these problems.
1.2.4 Some Examples from Industrialized Countries
Planning and management of land and water still present major problems in the industrialized countries, for example in containing urban sprawl, siting highways and airports, maintaining the quality of lakes and estuaries, and preserving wilderness areas.
Many of these problems are associated with the massive and mounting demands for energy and water by industry and a consumer society , and are present only in embryonic form in the less developed countries. The high farm yields of industrialized agriculture are based on very large energy inputs (pimental et al., 1973); and shortage of water _ once regarded almost as a 'free good' _ is 1ikely to cause serious problems for industry in many parts of Europe and the USA. In the United States, for example, where the energy consumption has been doubling every eight or 10 years, the projected cooling-water requirement for 1980 is about half of the normal run-off of the country. Even though 95% of this water is returned to the streams, its quality is not the same. Its higher temperature decreases the amount of dissolved oxygen and therefore the capacity of the streams to assimilate organic matter. This condition favours the development of decay food chains that further deplete the oxygen pool, and disturbs the stability of aquatic ecosystems.
The production of novel chemicals has introduced new environmental hazards and uncertainties. The addition of large amounts of biodegradable substances (nitrates, phosphorus - containing detergents, etc.) to the environment has accelerated the eutrophication of rivers and lakes, where these chemicals or their break- down products accumulate. Non-biodegradable chemicals may be less conspicuous but more dangerous. Some are concentrated as they pass through food chains and endanger the health of man and his domestic animals, as well as that of numerous other species of wildlife.
Crisis episodes like the 1952 London smog attract much attention, but long-term exposure to moderate degrees of pollution may be a more serious threat to human health and may have effects on human behaviour before physical ill-health can be recognized (WHO, 1972). It is right to emphasize effects on human health and well-being, but other significant effects should also be taken into account. Acute or even chronic human toxicity is only one part of the pollution problem; pollutants also have implications for the long-term maintenance of the biosphere. The short- term problems are much simpler, and are amenable in part to narrowly compartmentalized pragmatic solutions. Long-term effects of pollutants are insidious, chronic, and often cumulative. Ecologists must ask what effects these pollutants have on the structure of natural ecosystems and on biological diversity , and what such changes could mean to the long-term potential for sustaining life. The belief, held by some, that pollution, especially air pollution, is the most important index of the 'quality of the environment' is much too narrow. Many other forms of environmental degradation are of equal or greater long-term significance.
Development and redevelopment are taking place not only in the Third World but also within industrialized societies, with significant social ramifications in both cases. The situation in rural areas with long-established cultural patterns is similar in many respects to that in developing countries. Development may disrupt traditional ways of life, may inadvertently offend prevailing cultural practices, and may affect social cohesion, resulting in the break-up of communities. In urban areas, development may also cause substantial social stress. Urban motorways, for example, may sever established communities and may blight surrounding neighbourhoods.
During the remainder of this century , man will use as much of the earth 's natural resources, and tap as much energy, as he has during the whole previous course of human evolution. Economic expansion is likely to continue over the next few decades, although the growth of population and the consumption of the more readily accessible non-renewable resources will have to be greatly reduced in the longer term. The real question is whether mankind can channel this fantastic circulation of resources in ways that will better serve the needs of humanity (Ridker, 1973) while respecting ecological processes. In this context the developing art of technological fore casting ('futures research') may be of value in anticipating the possible adverse effects of new technologies (see Farvar and Milton, 1972), and (just as important) in being ready to exploit the new opportunities that result from advancing technology , creatively and with due concern for environmental restraints. Futures research may help both developed and developing countries to 'leap-frog' over many intermediate stages of development, either of particular technologies or of society itself. It is important, however, not to underestimate the conservatism of human societies and the great social stresses that are produced by rapid technological change.
1.3 RESPONSES OF SOCIETY TO THESE ENVIRONMENTAL CHANGES
Although the widespread concern about the human environment that culminated in the UN Conference on the Human Environment in Stockholm in 1972* is of relatively recent origin, there is a long history of practical responses to various kinds of environmental insults. Although some early agricultural societies appear to have perished because of problems of erosion and salinization, others developed highly productive terraced agriculture. Terracing, contour cultivation, and many other measures have been used for a long time to conserve soil and water .
The burning of coal was recognized as a major cause of air pollution in London as early as the fourteenth century , and its use, importation, and transport were regulated in various ways. Sometimes, capital penalties were imposed for producing 'pestilential odors'. From the fifteenth to the early twentieth centuries, various commissions and committees pronounced on the evils of air pollution, and William Blake (1757-1827) castigated England's 'dark Satanic mills'. But it was the great expansion of the chemical industry in the nineteenth century that led to the setting up of the Alkali Inspectorate in Britain in 1863 and the first comprehensive legislation to control the emissions from factories. Control of domestic fires did not come until much later. It required the 'smog' of 1952 which led to 4,000 deaths in London to bring this source of air pollution under effective control with the Clean Air Act of 1956.
Water pollution control commenced somewhat earlier. As the great towns of England grew in the early years of the nineteenth century , the death rates from water-transmitted fevers rose dramatically. The great sanitary reforms initiated by Edwin Chadwick in 1842-43 led to the Public Health Act of 1848, a landmark in the provision of safe water in cities.
Early in this century in North America, many measures were introduced to control erosion by water and wind. Somewhat later, integrated resource surveys were initiated. In 1912, President Theodore Roosevelt embarked on a series of proclamations designed to set aside land for national parks, preserving wilderness areas and natural ecosystems. Increasingly, too, the possible adverse environmental impacts of water-resource and highway development were recognized and steps were taken to investigate their importance during the planning stages of such enterprises.
But after World War II, government activities became more complex while both government and industrial enterprises increased greatly in scale and number. No longer could the public entrust the preservation of environmental quality to mission-oriented agencies, to industries motivated by profit or to regulating agencies charged with the evaluation of single-factor risks, like air or water pollution, which are relatively easy to quantify, Some mechanism was needed to ensure that all major development proposals by government and industry were subjected to an examination of their total environmental consequences. Although regulations of one kind or another devoted to this objective have now been introduced in many countries, the first comprehensive legislation was the National Environmental Policy Act (NEPA) of the United States, enacted on January 1, 1970. (See Appendix 2.) It was in this legislation that the terms 'environmental impact assessment' and 'environmental impact statement', that form the subject-matter of this book, were first used officially.
Because of the long lead-times involved in most major projects, many of the early EIAs in the United States were examined long after completion of the engineering and economic assessments. As a result, many environmental impact statements were presented to decision-makers as adversary documents. This situation is now changing. As indicated in Chapter 2, the proper time for detailed consideration of the environmental and related social aspects of new proposals is very early in their formulation, in para1lel with, and integrated into, the engineering and economic assessments.
*One reason for the growing environmental awareness of the 1960s was that measurement techniques improved and knowledge of dose-response relations increased rapidly.
1.4 THE SCALES OF INTEREST IN ENVIRONMENTAL IMPACT ASSESSMENTS
Experience in developed and developing countries alike suggests that the effects of large regional developments (power stations, dams, highways, and the like) should be considered on three time-scales.
Admittedly, the effects of some legislative proposals (e.g., plans to ban the sale of pesticides) cannot be sub-divided so conveniently into such discrete time-frames.
Environmental management strategies that include estimates of long-term impacts undoubtedly challenge the traditional decision making process. The political and economic bases for action are tuned to the immediate and short-range influences of the market-place. Here, cost-benefit analyses are based on interest rates related to present-day costs of investment capital, modified to account for uncertainty and risk and thus with a time-scale of 10-15 years. Economic systems aim to maximize gains over the short-term : ecological considerations suggest ways to minimize liabilities over the long-term.
In addition to the time-scales described above, several space-scales should be considered:
This book focuses on the process of impact assessment within single jurisdictions. The institutional and methodological considerations associated with large-scale and even global assessments require separate treatment. See, for example, the publication SCOPE 10, Environmental Issues (1977).
1.5 BIOGEOPHYSICAL AND SOCIOECONOMIC IMPACTS
In some jurisdictions, the term 'environmental impact assessment' is used broadly to include a whole range of social and economic impacts. Elsewhere, social impact assessment and economic analysis are seen as being quite distinct from an EIA in the organizations involved, professional skills used, and methodological approaches.
No matter how the terms are used, it is important to recognize that impacts on ecosystems, biogeochemical cycles, and the like are intimately related through complex feedback mechanisms to social impacts and economic considerations. The social impacts of any project that involves environmental changes should be studied : in close association with studies of biosphere impacts. These considerations are amplified in Chapter 6.
1.6 THE PREDICTION PROBLEM
When a project or programme is undertaken, it sets in motion a chain of events that modifies the state of the environment and its quality. To illustrate, a major highway changes the physical landscape which may, in turn, affect the habitat of some species, thus modifying the entire biological system in that area. The same highway affects land values, recreational habits, work-residence locations, and the regional economy. These various factors are interrelated, so that the net result is difficult to predict. A confounding factor is that if the project were not undertaken, environment would still exhibit:
One of the problems for the assessor, as indicated schematically in Figure 1.1, is to identify the various components of environmental change, due to the interacting influences of man and nature.
Figure 1.1 implies no value judgement of whether environmental change is good or bad. However, at some stage in the assessment or the decision-making process, such a judgement must be made.
The remainder of this book is organized as follows. Chapter 2 identifies the administrative procedures. Chapter 3 describes the components of an EIA, while Chapter 4, Chapter 5, and Chapter 6 describe existing methodologies. A number of examples and related topics are included in the Appendices.
Figure 1.1 Conceptual framework for assessing environmental changes. The reference condition is the 'without-action' condition and, because of naturally occurring changes, is not necessarily the present condition. The downward slope of the curves is for illustration only; an upward trend may occur in some cases.
Back to Table of Contents The electronic version of this publication has been prepared at
the M S Swaminathan Research Foundation, Chennai, India.