Population People

Posted January 1999

Special: Population, poverty and environment

Population and Environmental Change: from Linkages to Policy Issues

by Alain Marcoux
Senior Population Officer (Population and Environment)
Population Programme Service (SDWP)
FAO Women and Population Division

  • Population and poverty: the policy issues, by Geoffrey McNicoll
  • Population and environmental change: from linkages to policy issues, by Alain Marcoux
  • Rural poverty: population dynamics, local institutions and access to resources, by Eve Crowley and Kirsten Appendini
  • Anthropometric, health and demographic indicators, by Simon Chevassus-Agnès
  • Workshop report highlights
  • Introduction

    Population dynamics, poverty and environmental change are linked in many ways and through multiple social and economic mechanisms, at various geographic levels. But not all those linkages have relevance for policy formulation in one of the three domains thus interconnected. This paper tries to identify policy issues among the array of conceivable linkages, placing emphasis on environmental policy. It considers both the environmental issues regarding the management of natural resources and those regarding the pollution of humankind's living quarters. These groups, which broadly correspond to the respective concerns of the rural and the urban environment - the "green" and "brown" agendas - differ in nature, and population dynamics plays different roles in them.

    Like in all sectors, the search for policies that address population-poverty-environment linkages must be based on some representation of the nature of those linkages. But - like with population and development - there exist various, conflicting representations. I first quickly review the main perspectives and their general policy implications [1]. Then I offer some leads for a discussion on how population programmes and professionals can concretely operate within the context thus sketched.

    2. Alternative views on population-environment linkages

    Most theories of population and environment are expounded primarily in relation to agricultural resource usage, but they can be applied mutandis mutatis to all types of natural resources.

    For the natural science perspective humankind is one of the many species competing for the resources of the biosphere. As the resources of any ecosystem are finite, so is the latter's carrying capacity; hence, beyond a point, each additional inhabitant has a negative impact on the productivity of resources; this in turn depresses labour productivity and incomes (see Figure 1). Policy-wise, this perspective leads to advocate population stabilization. At first sight, it thus seems redundant with policy prescriptions that emphasize the need to slow down population growth for the sake of enabling more productive investment and a higher rate of economic growth.

    Figure 1. Population growth and natural resources: Poverty trap

    That, however, is not exactly the case. This perspective proposes that population growth must be stopped as soon as possible: this drastic goal is a logical consequence of explicitly raising the issue of the scale of human interaction with the environment (and therefore of limits to economic growth). Such a goal is not much on national agendas yet. The largely accepted policy merely seeks a slowdown; in fact, many of its proponents concede that slow population growth helps stimulate the economy, and they avoid to address the long-term view and the difficult question of an eventual upper limit to population size. The fate of natural resources and the environment is absent from this perspective, but the concept of sustainable development now imposes a re-examination of the problem.

    In fact, the two ideas (stabilizing population to protect the environment versus slowing population growth to foster more rapid economic growth) are at sharp variance. The problem is that economic growth, even coupled with slower population growth or even population stabilization, other things being equal, brings about greater environmental damage. The ICPD Programme of Action (henceforth PoA) does evoke repeatedly "sustained economic growth in the context of sustainable development", but the two concepts are mutually contradictory. In conclusion, this perspective does add a dimension to the "population slowdown" doctrine, but it is a thorny dimension that does not necessarily facilitate advocacy work.

    This view also recommends a balanced population distribution, i.e. a more even pressure on natural resources. It is difficult to make much of that policy-wise. First of all, the population of a given territory can exert very different degrees of pressure on land, water, biomass, and other resources, because those may be present in different quantities and qualities. Some concepts may be of help here, for instance the "potential population-supporting capacity" (PPSC) [2]. But human pressure also depends on resource-specific patterns of use, which also vary across space, cultures etc. Equalizing degrees of resources exploitation depends on much more than population distribution, because non-resident populations participate in that exploitation (e.g. urban dwellers require agricultural products or water - in greater quantities than rural people - so they too exert a pressure on rural resources). In sum, this policy recommendation is potentially very relevant, but it requires conceptual deepening and the development of appropriate methods of analysis.

    A major source of criticism to the natural science view is based on neo-classical economics and market-based adjustment mechanisms (see Figure 2). In this framework natural resources degradation is not necessarily a problem, since resources can be depleted at an acceptable rate, i.e. one that allows the market to replace those resources by alternative ones for the future ("efficient depletion"). Excessive degradation also may happen, either as a temporary consequence of population growth while adaptations take place, or as a structural problem where markets do not work efficiently (because some resources are not privately held and because prices do not reflect the scarcities and "sustainable values").

    Figure 2. Population growth and natural resources: Market-based harmony

    The policy prescription deriving from the neo-classical perspective is to give full efficiency to the market, meaning: define and price the use of common property resources; do not subsidize the exploitation of natural resources; and let the market, not the government, allocate resources. In this view population policy may "buy time", but it is not a "proper solution". This perspective leaves no role for population policies and programmes (else, of course, than their health value).

    A third perspective (sometimes labelled political ecology) argues that environmental degradation and rapid population growth are both consequences of poverty (see Figure 3). In this framework, resource degradation is the result of poor farmers eking out a living in marginal areas, with few resources and an inappropriate technology. Distortions in social structures, particularly unequal land distribution, inequitable relationships between landowner and tenants, limited access to credit, and biases in technology against small peasants, are designated as culprits [3].

    Figure 3. Population growth and natural resources: Dual effect of poverty

    Policy-wise, this line of thought sees usefulness neither in population policy nor in mere technical interventions (such as terracing to fight land degradation), that it regards as inefficient as long as the "real" factors of degradation are not addressed. Therefore, it advocates poverty alleviation, through a more equitable distribution of resources and the redressing of distorted relations both within developing societies and between countries. This policy conclusion is entirely redundant, since the objective of poverty alleviation imposes itself on mere grounds of human rights, without any need to assume that it is the single most effective manner of tackling environmental problems.

    Unlike natural resource degradation issues, there has been little analysis of the role of population dynamics in pollution. Soil, air and water pollution is mostly urbanization- and industry-related: rural pollution by agricultural chemicals (or local mining or industrial activities) is limited if compared to industrial wastes from urban areas [4]; domestic wastes are a much more serious problem in urban areas than in rural ones because they are emitted in much higher quantities on a per caput basis; and population concentration plays a specific role in that it physically makes the dispersion of pollutants in the air or water much more difficult.

    These problems cannot be much alleviated by population policies. They have to do mostly with [a] economic and technological models that favour mass production and place paramount value on GDP and income considerations, downplaying quality of life (including health) and the importance of a clean and pleasant environment; and [b] careless individual and household behaviour. Population composition has been shown to play a small part, in that household structure affects greenhouse gas emissions, but it is not likely to be a policy variable for emission reduction policies [5]. As for population concentration, it is the very substance of urbanization; of course, one may seek to keep population and housing densities within ecologically (and socially) acceptable limits.

    Some policies have attempted to reduce the rate of growth of urban agglomerations, but clearly the margins for intervention are limited in this domain. It is sensible to aim to harmonize urban population growth rates with the rates of growth of productive employment in cities, just like national policies aim to moderate overall population growth in order to enable tackling investment and equipment needs in a more progressive and orderly way. But this should be done by reducing the "push" factors in rural areas, especially when this leads to redressing unjustifiable inequities.

    Finally, population has been viewed as an intermediate variable: technical, economic or social variables (e.g. poverty, defective markets, polluting technologies, distortionary policies etc.) would work "through" population growth, which merely "exacerbates" the effects of these processes. Of course the broad policy conclusion then is that measures are needed to attack the "root causes". However, population policy in this framework is accepted, as it "buys time". Further, the population variable is viewed by some as more tractable than some other factors, especially those more politically charged such as the urban bias, land mismanagement or distortionary fiscal and price policies [6]. Accordingly, it has been for instance recommended to focus population policies on the more ecologically problematic areas, or to focus family planning efforts on landless families (thus also contributing to improve human capital).

    The above review seems to tell us that single-minded perspectives do not help very much in understanding the issues - nor in designing appropriate policies in response. In section 4, I shall propose some ideas for going further in policy analysis. Beforehand, however, I wish to take for a brief moment the advocacy viewpoint and offer a general defence of the relevance of the population variable.

    3. Environmental issues: relevance of population dynamics

    How do we enter the debate between the conflicting theoretical and policy perspectives when it comes to providing advice on their application at the country level? I think we have a duty to say that population dynamics do matter, and to show why and how.

    The pressure of human activities on natural resources can arise from a host of factors: a large or growing population; outside market demands; the nature of agricultural activities; or institutional, social and economic conditions which lead to the extraction of surpluses from the land managers, forcing them in turn to extract from the resources more than is sustainable. Such conditions may be: heavy tax or tribute; very low wages; denial of access to CPRs; low commodity prices due to state intervention or market distortions; indebtedness; and so on.

    In this context, population factors appear both as part of the basic conditions within which the socio-economic system operates (population density with regard to resources) and of the forces that affect its patterns of change (population growth, urbanization, migration). Density is relevant to the level of direct pressure on resources; population growth and urbanization affect the volume of market demands; urbanization absorbs land, and is conducive to biased pricing policies; a large and growing rural labour force contributes to low wages; excess demand for access to CPRs may shut out part of the population.

    Population dynamics must be taken into account, and it must be regarded as more than an exogenous variable: two-way linkages between population change and other elements of the system must be recognized. A systemic view of the "linkages" is therefore needed. This being said, what specific, self-standing policy recommendations can we reasonably sustain?

    4. A policy analysis perspective

    How should policy analysis orient itself in the "population-poverty-environment nexus"? The negative view of a nexus is that the elements are linked in a vicious circle, so that people are caught in a deadlock if not in a downward spiral. Figure 4 is a simplified image of one such nexus [13].

    Figure 4. "The P-P-E spiral"

    The detailed linkages in Figure 4 are as follows [14]:

    The positive view of a nexus is that progress in one of the interlinked sectors is likely to generate positive effects on the others. For instance: "[e]fforts to slow down population growth, to reduce poverty, to achieve economic progress, to improve environmental protection, and to reduce unsustainable consumption patterns are mutually reinforcing" (ICPD PoA).

    But, since efforts in one sector will meet constraints rooted in the other sectors, the question arises: if there are vicious circles of population-poverty-environmental change, how much do conventional policy formulations help? For instance, the ICPD PoA states that "[e]radication of poverty will contribute to slowing population growth and to achieving early population stabilization". But it also adheres to the common wisdom that sustained economic growth "is essential to eradicate poverty". On the other hand, rapid population growth is an obstacle to sustained economic growth.

    Ostensibly ignoring this vicious circle implies a belief that it can be broken simply by cumulating classical sectoral policies. Thus the ICPD's "comprehensive" view of population, development, poverty and environment did not produce any new policy perspective - because it contained no paradigm of the nature of the articulations between key phenomena. But in policy analysis work we cannot content ourselves with assuming general synergies: we must seek specific sectoral approaches that strengthen, and benefit from, those adopted in the connected sectors. In order to do that, we need to identify and address key articulation points of the single issues.

    Taking as a starting point the need for improving environmental policy, here follow a few ideas derived from the preceding considerations.

    5. Conclusion (provisional)

    By way of closing remarks I wish to address the research issue. The existing corpus of research on P-P-E linkages is disappointing. Methods often are questionable - like with much research on population and development in general - and "findings" often are contentious [19]. It is fair to note that population specialists have not participated much in these efforts so far. Yet, they can contribute significantly to the advancement not of an abstract "knowledge" of the linkages, but of policy making.

    For that, efforts should be targeted to shed light on specific decision problems. Initiatives could be taken in the context of population and development strategy support programmes, to illustrate to policy makers the potential practical value of the oft-repeated proposition about integrating demographic factors in the study of environment and formulation of related policies.

    Examples of this would be:

    In all cases, a necessary ingredient of this type of efforts would be experimentation on a variety of assessment and scenario analysis methods applicable to the substantive questions discussed here.


    1. Elements for the description of these theoretical frameworks (and the construction of the three illustrative diagrams) are borrowed from C. Jolly: "Four theories of population change and the environment", Population and environment, Vol. 16, No. 1, 1994, pp. 61-90.

    2. G. Higgins, A.H. Kassam, L. Naiken, G. Fischer and M.M. Shah: Potential population- supporting capacities of lands in the developing world. Rome, FAO/UNFPA/IIASA, 1982.

    3. This perspective descends from the theory of dependency, which sees environmental degradation as the result of changes in production systems and societal relations, mostly induced by the exploitation of the "center" over the "periphery".

    4. Incidentally, agricultural intensification is urbanization-related when it responds to a need for supplying growing quantities of food for the cities with a dwindling rural labour force.

    5. F.L. MacKellar, W. Lutz, C. Prinz and A. Goujon: "Population, households, and CO2 emissions", Population and Development Review, Vol. 21, No. 4, 1995, pp. 849-865.

    6. R.P. Shaw: "Rapid population growth and environmental degradation: ultimate versus proximate factors". Environmental Conservation, Vol. 16, No 3, 1989, pp. 199-208.

    7. A. Marcoux: "Potential population-supporting capacity of lands: environmental aspects". Population, Environment and Development, New York, United Nations, 1994, pp. 256-261.

    8. M.E. Cosio-Zavala: "Transitions démographiques et développement social dans les pays en développement". UN Expert Group Meeting on Population Growth and Structures, Paris, 1992.

    9. P. Blaikie and H. Brookfield: Land degradation and society. London, Methuen, 1987.

    10. In a country with very unequal agrarian structures like Guatemala, redistributing land entirely would offer a reprieve of no more than twenty years at current population growth rates before a situation of saturation returns (R. Bilsborrow, oral communication, Round Table on Population, Environment and Development, International Academy of the Environment, Geneva, 1993).

    11. R. Repetto: "Population, resources, environment: an uncertain future". Population Bulletin, Vol. 42, No 2, July 1987.

    12. P. Harrison: The third revolution. London, I.B.Tauris, 1992.

    13. The diagram is borrowed from UNICEF: State of the world's children 1994

    14. This purely illustrative diagram is not deemed an ideal representation of the linkages. Notably, it lacks an explicit environment --> population connection: some relevant linkages are hinted at in the poverty --> population link, but others (e.g. impact of environment-related diseases on mortality) are absent.

    15. United Nations: Agenda 21. Programme of action for sustainable development. New York, 1992.

    16. See endnote 9.

    17. What Blaikie and Brookfield (see endnote 9) wrote about land degradation applies more broadly to environmental change: it is "futile to search for a uni-causal model of explanation ... Any [such] attempt ... is somewhat akin to a 'whodunit', except that no criminal will confess, and Hercule Poirot is unable to assemble the suspects ... for the final confrontation ... However, any general statement about the causes ... is of a very different order from the usual 'whodunit', except perhaps in the case of the Orient Express, where all the suspects were found guilty!".

    18. The core issue in population-development-environment connections is the manner in which populations combine natural and other resources with labour. That manner is affected by socio-demographic factors (household size, sex/age structures, levels of education, nutritional status, and migration influence the quantity and quality of labour force) and by the availability and distribution of other production factors (natural resources, technical capital, finance). The ratio of human to other resources influences production and disposal technology, hence the rate of exploitation and quality of the environment. The outcome (product per person or household, environmental quality) determines wellbeing levels and quality of life. The expected productivity of labour in turn influences strategies on fertility and migration; etc.

    19. Much existing research seems geared to support a predetermined viewpoint (the "finding") through a purposeful interpretation of the factual elements at hand. None of it escapes the core methodological problem, namely that it is impossible to assess what the outcome of a given process would have been if the population growth rate had beeen different, or if poverty had been reduced, etc. (Correlation studies, which have been much used, are totally inadequate, because of inter-country heterogeneity with regard to a host of significant variables which are left outside the calculations.)

    Back to Top FAO Homepage