(introduction...)

Over the past thirty years, most of Sub-Saharan Africa (SSA) has experienced very rapid population growth, sluggish agricultural growth, and severe environmental degradation. Increasing concern over these vexing problems and the apparent failure of past efforts to reverse these trends led the authors to take a fresh look at the available research findings and operational experience. The objective was not to compile and address all of the agricultural, environmental, and demographic issues facing Africa or simply to juxtapose these three sets of problems. It was to gain a better understanding of the underlying causes and to test the hypothesis that these three phenomena are interlinked in a strongly synergistic and mutually reinforcing manner.

The need to survive—individually and as a species—affects human fertility decisions. It also determine people's interactions with their environment, because they derive their livelihood and ensure their survival from the natural resources available and accessible to them. Rural livelihood systems in SSA are essentially agricultural, and agriculture is the main link between people and their environment. Through agricultural activities people seek to husband the available soil, water, and biological resources so as to "harvest" a livelihood for themselves. Such harvesting should be limited to the yield sustainable from the available stock of resources in perpetuity so as to ensure human survival over successive generations. Improvements in technology can increase the sustainable yields or reduce the resource stock required. Population growth should thus be matched or surpassed by productivity increases so as to safeguard the dynamic equilibrium between the stock of resources and the human population depending on it for survival Over the past thirty years. this has not been the case in most of Sub-Saharan Africa.

This study's findings confirm the hypothesis of strong synergies and causality chains linking rapid population growth, degradation of the environmental resource base, and poor agricultural production performance. Traditional African crop and livestock production methods, traditional methods of obtaining woodfuels and building materials, traditional land tenure systems and land use arrange meets, and traditional gender roles in rural production and household maintenance systems were well suited to survival needs on a fragile environmental resource endowment when population densities were low and populations growing slowly. But the persistence of these traditional arrangements and practices, under severe stress from rapid population growth in the past thirty to forty years, is causing severe degradation of natural resources which, in turn, contributes further to agricultural stagnation.

Rapid population growth is the principal factor that has triggered and continues to stimulate the downward spiral in environmental resource degradation, contributing to agricultural stagnation and, in turn, impeding the onset of the demographic transition. The traditional land use, agricultural production, wood harvesting, and gender-specific labor allocation practices have not evolved and adapted rapidly enough on most of the continent to the dramatically intensifying pressure of more people on finite stocks of natural resources.

Many other factors also have a detrimental impact on agriculture and the environment These include civil wars, poor rural infrastructure,lack of private investment in agricultural marketing and processing, and ineffective agricultural support services. Inappropriate puce, exchange rate, and fiscal policies pursued by many governments have reduced the profitability and increased the risk of market-oriented agriculture, prevented significant gains in agricultural productivity, and contributed to the persistence of rural poverty.

A necessary condition for overcoming the problems of agricultural stagnation and environmental degradation will be, therefore, appropriate policy improvements along the lines suggested in the 1989 World Bank report on Sub-Saharan Africa's longer-term development prospects (World Bank 1989d). These policy changes will be instrumental in making intensive and market-oriented agriculture profitable—thus facilitating the economic growth in rural areas necessary to create an economic surplus usable for environmental resource conservation and to provide the economic basis for the demographic transition to lower population fertility rates. That this can occur has been demonstrated in a few places in Africa that pursued good economic and agricultural policy, invested in agriculture and natural resource conservation, and provided complementary supporting services to the rural population. This study provides evidence for both the causes of the problem and its solution.