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11. Comparisons and conclusions

Regional trajectories of change
Human driving forces
Societal response
Generic patterns and issues
The larger issues

B. L. Turner II, Jeanne X. Kasperson, Roger E. Kasperson, Kirstin Dow, and William B. Meyer

The original impetus for this volume was the exploration of the concept of environmental criticality in a series of regional case-studies across the globe. During the exercise, the concept of criticality was refined by adding the categories of sustainability, impoverishment, and endangerment. Guiding our study were several central questions: (1) do critical environmental regions exist, as defined in chapter 1, and do certain regions popularly supposed to be in a state of environmental crisis meet the definition? (2) can we characterize and explain the human-environment interactions that have led to growing criticality; and (3) how have societies responded to emerging environmental degradation, and with what success? In addressing these questions, the various contributors to this volume have focused on environmental changes largely internal to each area (in our usage, "cumulative" change) and not on "systemic" global changes (such as climate change or stratospheric ozone depletion) that might, over the longer term, affect ecosystems and human life in the regions (Turner et al. 1990b). Eschewing narrow "geocentric" and "anthropocentric" approaches (see chap. 1), we have sought a more integrative assessment of the unfolding threats posed by environmental change over time. Attention to historical and regional contexts has been central in such assessments. The analyses that follow focus on changing regional trajectories in nature-society relation ships and the "regional dynamics" of change that shape such trajectories.

Several aspects of this enquiry require clarification. Human use invariably alters an environment, an alteration that from a purely ecological or "geocentric" perspective may be interpreted as environmental degradation. But such human use often, perhaps even usually, increases the value of the environment, at least over the short run, by harnessing it for economic returns. Environmental degradation may follow, but so may a growing ability of the users to repair damage and sustain the environment. Thus, the capacity of society to respond, either through substitution in the productive system or through additions to the buffering capacity of the ecosystem, is a key consideration in judging the health of the nature-society relationship. Sustainable uses are those in which the environment can meet and absorb the human demands placed on it over the long run. Degradation and sustainability in this perspective are functions of economics as well as of the biophysical environment.

These considerations are not easy to apply in practice because of several complicating factors that qualify our assessments of the trajectories of and prospects for the nine regions dealt with in this volume. The growing role of interregional and international trade, and of external political control over local uses of the environment, geographically separates the human driving forces of change from their environmental impacts. The more "open" the use-environment system in our regions, as illustrated in figure 11.1, the more difficult it is to assess long-term trajectories of change and their ultimate consequences, in part because of the ability to change the regional use system, to substitute critical inputs from elsewhere, or to export degradation to other regions. (Such transfer of demands and impacts is possible, of course, only so long as other regions exist that are capable of absorbing them; the development of regionally unsustainable pressures in many areas simultaneously could conceivably accumulate to a global threat.)

Every region studied in this volume has experienced significant environmental alteration through increased human use, but almost every region (with the glaring and recent exception of the Aral region) has also enjoyed overall improvements in per capita wealth and well-being for most inhabitants. This result is not surprising; it is a pattern recurrent in history (see the regional studies in Turner et al. 1990a). The important considerations in judging the state of each region are the sustainability of the present use-environment relation-ship and the range and diversity of options available to current and future human occupants. These options vary, of course, with both the physical and the political-economic environment. The resource base can continue to be severely degraded if the regional economy is sufficiently robust to provide substitutes or if it becomes increasingly disengaged from dependence on the natural resources and sinks of the regional environment. No economy, however, is infinitely robust, and, if environmental degradation increases, a point must eventually be reached at which substitution becomes uneconomical, the assimilative capacities of the environment are exceeded, and/or the rate or scale of degradation overwhelms the capacity of society to respond. The environment-use relationship then proceeds through impoverishment and endangerment to criticality. In such cases, major restructuring or human adjustment is required, usually with severe, although sometimes transitory, human impacts.

Fig. 11.1 Open and dosed regional systems

This chapter offers initial answers to the questions posed above. It is a preliminary analysis, an interim report on the results from the nine case-studies and our current thinking. The regional analyses are still in progress and will be reported in greater depth in a forthcoming series of books. We begin with a comparison of the patterns of change in nature-society relationships in the nine regions and the generic issues or questions that can be gleaned from these patterns. Next, we consider the major human driving forces of change in each region and the patterns of change in human and ecosystem vulnerabilities. Then we compare the societal responses to emerging environmental degradation, probing for the sources of intentional exploitation and mitigation, timely response and delay, concern and neglect, and effective and ill-conceived adjustments and adaptations. We go on to discuss the advantage of a common protocol in revealing broad patterns and trajectories of change, all the while mindful of the constraints imposed by the incompatibility of quantitative data across case-studies. We conclude with observations addressing research and public policy.

Regional trajectories of change

Although lacking thorough and comparable quantitative data, the nine case-studies do provide information about broader human-environment trends threatening the human occupation or use of the regions. They permit estimation of general aggregate trends in environmental change, per capita well-being, and the sustainability of the current human-environment interactions for each region.

These aggregate trends are graphed in figure 11.2, where the X-axis is the time-period of the trend lines (approximately 50 years ago to present), and the Y-axis is the amount of environmental change, the level of per capita wellbeing, and the judged long-term sustainability of human uses. The height at which the trend lines begin along the Y-axis indicates the relative position of each at the time of the beginning of the study (some regions had already experienced significant change).

Fig. 11.2 Regional changes in environment, human well being, and sustainability of uses

Two cautions are necessary before proceeding. First, we emphasize aggregate conditions because we are dealing with each region as a whole, not with specific individuals, subgroups, subregions, or ecosystems. These aggregate trend lines, as we pointed out in chapter 1, conceal marked internal variation that may be important in interpreting the human consequences of environmental change or in structuring the regional dynamics of change that determine the trajectory toward greater endangerment or criticality. Thus, a series of disaggregated analyses are required in analysing the regional dynamics of change. Well-being per capita may be stable or rising in the aggregate, yet falling among social groups constituting a significant proportion of the regional population. This impoverishment of particular classes or groups may interact with existing vulnerabilities and ecosystem fragility to produce "spirals of land degradation" (Blaikie and Brookfield 1987; Kates and Haarmann 1992). Second, the specifics of each trend line are debatable, based as they are on our judgements of each case-study and comparisons among them rather than on specific quantitative measures. We are relatively confident, however, in the overall shape of the trajectories. Herein lies their major significance. They chart the broad courses of regional changes in environment, human well-being, and sustainability of uses in the nine regions.

The categories of regional environmental status outlined in chapter 1 permit a more generic assessment of the state of the regions. To repeat our definitions, impoverishment is the condition in which current human uses and levels of well-being appear to be environmentally unsustainable over the middle- to long-term future and in which the options available to the future are being significantly narrowed by the current draw-down of natural capacities; endangerment involves overall human uses of the environment that appear to be unsustainable over the near term (this and the next generation) in the absence of radical adjustments in their scale or composition; criticality is the condition in which the environment has been so seriously degraded that the human condition (wealth and well-being) is already deteriorating as a direct consequence of environmental changes. Any condition not categorized as one of the above is judged to be sustainable. No representatives of this last category occur among our nine regions, which is not surprising given that they were selected because they showed strong indications of unsustainability. As these definitions suggest, the imminence of consequences is a central consideration in this analysis, whereas the steepness of, and possible non-linearities in, the trajectory of human-environment relationships are key factors in an assessment of such imminence.

Human uses of a regional environment require certain inputs and offer certain returns. A human use becomes unsustainable if the cost of the inputs rises or the value of the returns falls to a sufficient degree and if the deficit is not made up from some other source. A region is environmentally threatened if human-induced environmental changes have made the current use unsustainable either at present or in the likely near- to medium-term future and if no alternative use exists that would sustain the same level of wealth and wellbeing. In this relational view, the maintenance of a region over time depends primarily on two factors: (1) the return available from the use of the environment, and (2) the availability of subsidies to make up the difference if the net return of the use is inadequate. (Such "subsidies" can include the externalization of costs to marginal groups that have little say in decisions.) We term the first factor "environmental recoverability" and the second "sustainability of use costs." Changing nature-society conditions (impoverishment, endangerment, criticality) can result from a decline in "environmental recoverability" as a result of the draw-down of the environmental resource base, possibly exacerbated by a decline in the "sustainability of use costs" for any of a number of reasons (such as decline in the political power of the region, decline in regional wealth, or change in terms of trade). The three states of increasing environmental threat (impoverishment, endangerment, and criticality) are characterized by different trajectories and relationships in the two trend lines. Figure 11.3 illustrates the movement of a hypothetical region from sustainability to criticality through deterioration in both recoverability and sustainability of costs, whereas figure 11.4 suggests how these trends relate to emerging environmental criticality. Figure 11.5 depicts our judgements as to these trends in our nine regions and their trajectories toward greater endangerment and criticality. Table 11.1, in turn, provides an overview of our judgements concerning the current states of nature-society trajectories in the nine regions and the degree of confidence we have in the probable accuracy of our judgements.

It may be that all nine of the regions in this study (and perhaps almost every inhabited region in the world), if recent past or current trends were to continue unabated, would soon enter some stage of impoverishment or endangerment. In this sense, every region is one in which some level of long-term endangerment exists. In assigning a regional case to one of our categories of impoverishment-endangerment-criticality, we have judged the likelihood that recent trends will continue, whether they can be altered by feasible adjustments, and whether such human adjustments are possible in a time-frame to prevent the onset of severe consequences. Obviously, such judgements are debatable and our analyses envision them as heuristic and suggestive rather than conclusive. Ideally such assessments should move from these subjective assessments to more quantitative expressions of particular indicators.

Human adjustments, often leading to partial recovery from the environmental damage and to total recovery or even improvement in human well-being, have been common throughout human history. Viewed over the short run, the trajectories of environmental and social change may appear to be inexorable, but, over the long run, regions typically display a fluctuating long-wave path in which environmental deterioration and social well-being are linked, only to be followed by a social rebound (e.g. Berry 1991; Whitmore et al. 1990).

Fig. 11.3 Regional movement to environmental criticality

The studies in this volume, it should be emphasized, assess regional, not global, environmental implications. This regional emphasis can lead to assessments that differ from some conventional wisdom about the planet as a whole. For example, we do not consider the possible contribution of deforestation to global climate change, or the cutting of tropical old-growth forests in terms of potential long-term economic losses resulting from a decrease in biodiversity. Local users rarely make decisions in terms of global environmental implications, and evaluating long-term potential losses from decreased biotic diversity is a highly speculative exercise at this time. On the other hand, we are concerned with the long-term implications associated with the rapid draw-down of nature that is so common in our regional cases and the associated impacts on the security and well-being of future generations. With these considerations in mind, we turn to our individual regional studies for brief characterizations by which to interpret figures 11.2 and 11.4 and table 11.1.

Fig. 11.4 Regional trajectories and emerging criticality

Fig. 11.5 Regional trajectories of environmental recoverability and the sustainability of use costs


Environmental change has been rapid and significant indeed in Amazonia. The foremost impact has been deforestation as a result of cropland and grassland/pasture expansion, timber extraction, and flooding for hydroelectric power reservoirs. The rate of land-cover change may, however, be slowing. In addition, mining (largely small-scale gold prospecting) has released toxic chemicals into the drainage system, affecting water quality and, potentially, the health of downstream populations.

Consequent changes in human well-being are difficult to assess because most of the region's inhabitants are recent in-migrants, many of whom are fleeing poverty elsewhere, and because of the differing economic situations of large landowners, smallholders, and indigenous peoples. For these reasons, and considering the rapid population growth in this region, a low-growth trend in human well-being is appropriate. The sustainability of use decreased markedly in the initial rush to develop the region, but it may now be approaching stabilization in some production activities (e.g. agriculture and livestock-raising). Given the demonstration that ecologically and economically sustainable systems of production are possible and the potential slowing of the pace of deforestation, Amazonia may prove a classic case of a frontier that experiences a transition to more settled and sustainable conditions. Much depends upon interventions that are only beginning. Also, as Smith and his colleagues indicate, multiple trajectories are at work within the Amazon, some leading to greater and some to less environmental degradation, whereas overall wellbeing, except among indigenous groups, continues to increase.

Table 11.1 Comparison of the status of the nine regions

Region Status
Impoverished Endangered Critical
Amazonia **    
Sundaland ***  
Ukambani * *  
Nepal middle mountains **  
Ordos Plateau **    
Aral Sea ***
Llano Estacado *  
Basin of Mexico *  
North Sea ***    

=partial = broad-based
*** = high, ** = medium, * = low degree of confidence that classification is correct
Note: a low level of confidence implies that the evidence is sufficiently inconsistent or uncertain to lead to different outcomes.

Based on these findings, we assign Amazonia to the environmentally impoverished category. The pace of deforestation (which recent information, e.g. Bonalume 1991, suggests may in any case have been much slower than previously thought) appears to have slackened and uses have emerged that appear better attuned to the environment. It remains to be seen whether the slower pace of change, improvements in land management, and an enhanced ability to sustain the costs of inputs for land-use development will continue.

Eastern Sundaland

Like Amazonia, eastern Sundaland has witnessed rapid environmental change and considerable variation in the associated consequences for different social groups. The primary environmental impacts are substantial deforestation and associated soil degradation (from compaction); the cut-over forest also becomes highly susceptible to fires (from both human and natural sources) and the loss in biodiversity is notable.

The immediate sources of deforestation are timber extraction and agricultural development. The former as it is currently practiced (especially in Borneo) appears to be unsustainable; its scale and pace far outstrip replanting or natural regeneration. The bountiful economic rewards derived by the timber companies, local loggers, and timber mill workers from the "mining" of the forest cannot long continue. Much of Borneo (except Sabah) is endangered, but a caveat is in order. Deforestation is taking place in sparsely occupied areas (to the detriment, certainly, of the native inhabitants) that are likely to reforest. Of course, the new-growth forest will not be the same as the old, but it is not clear that the future environment will be significantly more hostile to human use than it was before logging, save locally where some soil degradation is bound to occur. Agricultural development activities suggest another story. Systems being adopted, especially tree estates, appear to be ecologically suitable, although more time is needed to determine if they will be economically sustainable as well.

Overall, therefore, our trend line for the sustainability of uses in the region internalizes two very different cases: logging and agriculture. Both activities have led to considerable environmental change, although the change attributable to agriculture is considered benign compared with that of logging. The latter, in terms of its pace, magnitude, and management, is devastating, with two caveats: much of the population appears to benefit from a significant "trickle down" of economic gains, the ultimate impacts of which are not known, and much of the deforestation is taking place in relatively remote areas that may regain forest, albeit not the mature growth that has been and is being cut. The loss of biodiversity, however, could have long-term regional implications, removing a significant environmental asset for the future. Meanwhile, societal responses to halt the depletion of these old-growth forests are dilatory and still quite ineffective. Finally, it is uncertain whether the agricultural systems that are emerging will be economically sustainable.

For these conflicting reasons, we consider the region as a whole to be in an early stage of partial endangerment. By this we mean that the pace, magnitude, and management of timber extraction - widespread as it is throughout the region - appear to be creating conditions ripe for a large-scale future collapse or ultimate decay of the regional environment and economy.

Ukambani (south-eastern Kenya)

Ukambani has witnessed a major shift in land uses from those based largely on pastoralism to increasingly intensive cultivation. Farmers have increasingly moved down-slope from the wetter highlands into semi-arid Ukambani seeking land and livelihood. The accumulation of land pressures has made it impossible to continue the multiple uses practiced in the past, including the use of different niches at different times of the year. It has increasingly forced resource-poor farmers to sustain themselves on fixed portions of semi-arid land, with mixed results. On the better land, some farmers have prospered, becoming successful large-holders with improved, intensive cultivation. Other farmers, on more marginal land, have been less fortunate, lacking the resources and labour to make land improvements. Their lands display numerous indicators of environmental degradation - soil erosion, deforestation, overgrazing, and loss of soil moisture and biodiversity. Given the variability in rainfall, periodic famines have been recurrent (1946, 1951-1952, 1961, and 19841985). Owing to these mixed results, we characterize this region also as in early endangerment, but it appears to be at a crucial juncture from which it could move in its trajectory either toward greater stabilization or to greater endangerment.

The Nepal middle mountains

Recent environmental changes in the Nepal middle mountains have been significant, but geographically variable. They have largely been those associated with land-use intensification lacking adequate inputs: cropland and pasture degradation, deforestation, and (probably) increased irregularity of water flow through drainage systems, an important impediment to irrigation.

Unlike Amazonia and eastern Sundaland, the middle mountain zone of the Nepalese Himalayas has had a substantial and growing population for over 100 years. Until recently, production was principally for consumption rather than for the market. The environmental impacts of the past several decades reflect changes in the agricultural system: a shift to market production on improved land, and intensified and expanded consumption production by marginal farmers and herders on less productive and more fragile land. The economic consequences of commercialization, of course, have not been uniform and, because much of the wealth generated ends up highly concentrated in Nepal or outside the region (especially in India), material well-being has not kept pace with the scale of production changes. The predominantly rural population remains in desperate economic straits but probably better off in several respects (e.g. health, social services) than in previous periods. Many of these changes are marked by environmental degradation, but as yet no indication exists of an impending overall collapse of the regional human use-environment system. Meanwhile, conflicting evidence points to both continued environmental degradation and some adjustments that are lowering the rate of degradation. This case, therefore, is one of endangerment.

Ordos Plateau

The Ordos Plateau region has witnessed significant changes in human-environment relations in a sensitive environment. The expansion and intensification of agriculture have caused a decline in grassland cover, which, in turn, has promoted soil degradation. Large-scale gully erosion dominates the landscape. The loss in sustained annual vegetation (and especially grassland cover) has contributed to wind erosion and increased "sandification" (the spread of sand-dunes), which, in turn, threatens livestock and agricultural land. The introduction of woollen industries has intensified livestock production and grassland degradation throughout the region. Industrial and population growth have depleted groundwater supplies, while coalmining has generated surface water pollution in parts of the eastern Ordos. Central state policies have intentionally promoted migration, cultivation, and industrial development in the Ordos but have been less successful in dealing with environmental impacts or their immediate human causes.

Although the human forces of change have slowed since 1978, and various measures have been adopted to combat degradation, it is not clear that the loss of key resources (soil and grass cover) has yet abated sufficiently, or that enough will be done in the near term to offset the trajectory of these losses and to put the system on a more sustainable path. Owing to this uncertainty, and the facts that some indicators of well-being (health, education) are improving and that some effective societal responses are occurring, we classify the Ordos Plateau as an impoverished zone, though a greater degree of endangerment is likely unless recent trends of environmental response, better land management, and economic growth continue.

Aral Sea

The Aral Sea case is one of criticality by any measure. Massive environmental degradation has taken place in land cover, water discharge, and water and soil pollution, mainly through the desiccation of the sea itself and the associated devastation of the human population and regional economy. The environmental impacts have been documented in detail. The irrigation system overtaxes the availability of water, leading to losses in irrigated land and to major shortfalls in the amount of fresh water entering the Aral Sea (virtually none at certain times of the year). Much of the sea has dried up, and its once lucrative fishing industry has been destroyed. With the sea's moderating influence on the local climate diminished, less precipitation falls and more sand storms occur, with wind-blown salts from the exposed sea floor degrading regional grasslands and contaminating water as far away as the drainage headwaters. Meanwhile, the chemical-based agricultural system has severely polluted soil and drinking water and, along with wind-blown salts, has apparently produced major health problems, increased infant mortality, and even premature deaths. In face of these major problems, however, the region has grown significantly in population and in material infrastructure (e.g. urban areas, buildings, roads).

The massive irrigation systems that have brought on these impacts cannot be sustained, and a scaling back of cultivation must ultimately occur. Per capita well-being has been dropping, particularly in terms of severe health problems associated with pollution. Whereas adjustments are necessary and are likely to occur eventually, they will have to be of a major magnitude (even, perhaps, an international rescue effort) to arrest the rapid movement to regional catastrophe. Meanwhile, the societal capability to respond to the situation, in view of the breakup of the former Soviet Union, the disarray of the regional economy, and political disintegration within the region, has plummeted in relation to the rapidly accumulating disaster.

The Aral Sea case, therefore, meets the criteria of a critical region in our terminology. The environment has been devastated; much of the environmental damage cannot be repaired save at prohibitive cost or over the long run; the well-being of the region's population has been dropping precipitously owing to the environmental changes; and no solutions to rectify these conditions appear on the horizon. It should be noted, however, that these conditions have emerged after 30-40 years of sustained economic growth.

Llano Estacado

During this century, the semi-arid Llano Estacado has witnessed at least one and a half boom-bust cycles: expansion of agriculture, dust bowl, and return of agriculture. In the first cycle, rainfed cultivation and livestock-raising predominated. The draw-down of the regional aquifer largely supported the second boom, making possible an expansion of irrigated agriculture with substantial economic rewards. The major consequence of the change in land use has been severe stress on the southern Ogallala aquifer and on soils. Groundwater is being depleted at an increasing pace, and soil erosion has increased on exposed or degraded agricultural lands.

Aquifer depletion, the most significant form of environmental change in the region, raises issues of the longer-term sustainability of rural land use. It is obvious that the current mode of mining of the aquifer is not sustainable over the long run, and adjustments in the use of groundwater and other agriculture/livestock activities are already under way. Without changes in market conditions, however, new land-use practices may not be as economically rewarding as those of the recent boom. For this reason, we judge this region as partially endangered, with a growing overall risk of eventual regional collapse of the current rural land management practices. We add the "partial" qualifier because this region is part of a wealthy society that subsidizes it and because the regional population possesses substantial technological, institutional, and economic resources to engineer favourable outcomes in the face of serious environmental stresses.

Basin of Mexico

With a long history of modification, even transformation, the Basin of Mexico has been radically altered still further since the middle of this century by the growth of an industrial mega-city. The consequences of this massive urban-industrial development in an enclosed basin are ominous. Industrialization, including energy production and transportation, has created such extensive pollution that the air of the basin is literally unsafe to breathe and serious health problems have emerged. Surface water is widely contaminated. Water demand long ago exceeded the supply available within the basin, so much so that continuing and costly inputs are required to meet daily needs.

Owing to the extraordinary pace of in-migration and growing density of settlement, aggregate human per capita well-being in the basin is already dropping, even if it represents an improvement for many over the poverty from which they have migrated. Growing health problems represent an important dimension of environmental "bite-back" and may portend the fate of many other emerging world mega-cities. Only radical adjustments will rectify these trends. Meanwhile, societal responses have been ineffective in that they have largely concentrated on mitigation rather than alteration of basic human driving forces or have sometimes even inadvertently accelerated the trajectory to criticality. For these reasons, one must consider the Basin of Mexico as at an advanced stage of endangerment, nearing criticality.

North Sea

Human actions have long transformed the rimlands of the North Sea. The major process of environmental change today is marine pollution from industrial and consumption activities. These activities threaten the age-old fishing industry and may also adversely affect health and recreation. It is clear that the sea as an ecological unit cannot much longer sustain the trajectory of human uses associated with advanced industrialization and urbanization. Ultimately, oil and gas under the sea will be depleted, with significant economic consequences for the rimlands (but consequences for which proven substitutes exist).

What makes this case somewhat different from the others is that the ecological degradation experienced does not fundamentally threaten the regional economy. The fishing industry and other productive uses of the sea, excepting oil and gas extraction, are not fundamental to the livelihoods of most inhabitants. The region has very high societal capability to respond to the degradation, and social mobilization in behalf of environmental issues is at a mature stage of development. Because of this wealth of the rimlands and the high overall societal capability to respond to the degradation, the North Sea is at most a case of environmental impoverishment. Indeed, the strongest implications of current trends are for future peoples rather than for current generations.

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