Food Policy 25 (2000) 479–498www.elsevier.com/locate/foodpolA downward spiral? Research evidence on therelationship between poverty and naturalresource degradationSara J. Scherr*Agricultural and Resource Economics Department, 2200 Symons Hall, University of Maryland, CollegePark, MD 20742, USAAbstractMany observers have conceptualised the link between rural poverty and environment as a‘downward spiral’ with population growth and economic marginalisation leading to environ-mental degradation. Recent micro-scale empirical research challenges this model, showingstriking heterogeneity in environmental management by the rural poor, their success in adapt-ing to environmental change and the efficacy of policies in influencing outcomes. Local endow-ments, conditions affecting the adoption of resource-conserving technologies and local insti-tutions supportive of the poor are key factors that condition poverty–environment interactionsand outcomes in relation to agriculture. The main strategies to jointly address poverty andenvironmental improvement are to increase poor people’s access to natural resources, enhancethe productivity of poor people’s natural resource assets and involve local people in resolvingpublic natural resource management concerns. Research is needed to support these strategies,particularly to explore poverty–environment–agriculture interactions, develop technologies forpoor farmers and partner with local communities for action research on policies and pro-grammes.  2000 Elsevier Science Ltd. All rights reserved.Keywords: Agricultural policy; Downward spiral; Environmental degradation; Land degradation; Ruralpoverty; Smallholder agricultureIntroductionAgriculture accounts for most land use in developing countries and thus is prob-ably the single most powerful influence on environmental quality. At the same time,* Tel.: +1-301-405-8360; fax: +1-301-314-9091.E-mail address: [email protected] (S.J. Scherr).0306-9192/00/$ - see front matter  2000 Elsevier Science Ltd. All rights reserved.PII: S0306-9192(00)00022-1480 S.J. Scherr / Food Policy 25 (2000) 479–498agriculture remains the principal livelihood of the rural poor (Malik, 1999). Yetpatterns of rural population growth, agricultural expansion and intensification andincome growth projected for the next few decades pose serious challenges to achiev-ing both environmental improvements and rural poverty reduction (Pinstrup-And-ersen et al., 1997). Indeed, many policymakers assume that a ‘downward spiral’ ofrural poverty and environmental degradation constrains development options andnecessarily forces unpalatable policy trade-offs. This paper examines this assumptionin light of new evidence and draws policy and research implications.Poverty–agriculture–environment: a ‘downward spiral’?The nexus of poverty, agricultural production and environment poses controversialpolicy and research challenges. Our ‘mental models’ of the relationships betweenthese points of what Vosti and Reardon (1997) call the “critical triangle of develop-ment objectives” powerfully shape policy and research design.Environmental issues related to agriculture and the poorEnvironmental concerns associated with agriculture relate mainly to the sus-tainability of the resource base for agricultural production (e.g. soil quality), protec-tion of biodiversity and habitats, and environmental services of resources influencedby agricultural land use (e.g. carbon sequestration). Degradation of soil and vegetat-ive resources already threatens agricultural productivity, biodiversity, and water qual-ity and availability in many ‘hot spots’ in the developing world (Scherr and Yadav,1996). Soils in about 16% of agricultural land area in developing countries, and ahigher proportion of crop and dry lands, have degraded moderately or severely sincemid-century, mainly through soil erosion, nutrient depletion and salinisation (Scherr,1999a). At least 28 countries, with a total population exceeding 300 million people,face water stress today, and demand is growing rapidly even as water contaminationcaused by agriculture and rural domestic uses increases (Pinstrup-Andersen et al.,1997). Declines in agrobiodiversity increase disease and pest problems. Agriculturalexpansion, intensification and devegetation are the leading causes of species loss anddepletion of natural vegetation.Wealthier farmers, developers and multinational corporations typically controlgreater total land area and play a prominent role in many types of environmentaldegradation. However, the poor play a significant role in unsustainable agriculturalintensification, expansion of farming into marginal lands and vegetative overexploit-ation and the consequences for their livelihood can be more serious because theylack assets to cushion the effects.Agriculture–environment–poverty interactionsSince the late 1980s, it has been widely accepted that the interaction of agriculturaldevelopment with the environment must be explicitly considered, both to ensure the481S.J. Scherr / Food Policy 25 (2000) 479–498long-term sustainability of production systems and to mitigate negative effects onlocally and globally important ecological goods and services. This new approach hasbeen dubbed the ‘doubly-Green Revolution’ (Conway, 1997).That agricultural growth (especially growth and stabilisation of food staplesproduction) can be a powerful strategy to benefit poor people is also widely agreed(Malik, 1999). In most regions, the rural poor depend more for their livelihoods onagricultural production and employment, and on common lands, than do the ruralnon-poor. The former’s prosperity depends substantially on the forward and back-ward production linkages—and even more on consumption linkages—from farmers(Reardon and Vosti, 1992). Poverty is recognised as a significant constraint on agri-cultural growth because of poor people’s need to concentrate resources on lower-value food crops to ensure subsistence security and their difficulties in mobilisingproduction and investment resources.The more controversial side of the critical triangle has been poverty–environmentinteractions. Much of the early literature on this relationship posited a ‘downwardspiral’ of poverty and environmental degradation. In this model, poor people placeincreasing pressure on the natural resource base—resulting from population growth,limited access to land or access only to poor