Various human factors drive, influence and affect environmental change at the global, regional, national and local levels.

Drivers of environmental change vary in nature and scope but can be broadly grouped together as demographic, economic and social, science and technology, conflict and governance. Critical social dimensions include poverty and health. Policy and institutions, although most often thought of as the response to mitigate such change, may also drive environment change and impact directly on human vulnerability. Although each driver is discussed individually, there are links between the different drivers - sometimes acting in concert to maximize negative impacts and sometimes producing positive change.


By 2030, the
proportion of
Africa’s urbanized
population is
expected to reach
53.5 per cent,
compared to
39 per cent in 2005.

compiled from WRI 2005

People in Africa are at the centre of sustainable development – in rural and urban areas. Although still largely rural, the region has been experiencing major transformation in terms of population composition and distribution, with positive and negative implications for the environment and development. The challenge is not to arrest development but to use the available resources in a more productive and efficient manner, ensuring better and more equitable returns to people while at the same time lessening pressure on the environment.

Changing demography, and particularly the changing age structure of the population, a high rate of urbanization, and a faster rate of population growth in relation to economic growth are major drivers of environmental change in Africa, with significant impacts on the natural resource base. Due to this, it is imperative that population growth and its structural changes are addressed to reduce environmental degradation. Each year, the number of people increases, but the amount of natural resources with which to sustain this population, to improve the quality of lives and to eliminate poverty remain finite (WCED 1987), increasing the challenge of sustainable development. Demographic change is the major driver of land cover change: its primary and most direct impact is through opening new land for agricultural, settlement and infrastructural development (UN Millennium Project 2005a), although other extractive activities such as logging and mining are also significant. Section 2: Environmental State-and-Trends: 20-Year Retrospective assesses the state of Africa’s environmental assets and some of its chapters also consider the relationship between human settlement and environmental change.

Figure 1: Population growth in twentieth-century Africa At the beginning of the 20th century, the total population of Africa was about 118 million, accounting for 7.4 per cent of the global population (United Nations Population Division 1996). From 1980 to 2000, it grew from 469 million to 797 million, representing 13 per cent of the world population in 2000 (FAO 2003). By 2020, the urban population is expected to be 646 million up from 302 million in 2000 (FAO 2003). While insufficient data exists to accurately ascertain the magnitude of urbanization, available statistics indicate a current rate of urbanization in Africa of around 3.5 per cent per year (UNCHS 2001). This rate is the highest in the world, and is resulting in the rapid growth of urban agglomerations throughout the region. By 2030, the proportion of Africa’s urbanized population is expected to reach 53.5 per cent, compared to 39 per cent in 2005 (compiled from WRI 2005). This fast rate of urbanization places strain on infrastructure and other services. Many of the newly urbanized live in slums. There is a growing and urgent need for integrated approaches to environmental planning and management.

In the absence of alternative livelihood opportunities and strategic management of the environment, this rapid population growth and urbanization has resulted in environmental degradation and resource depletion. Between 1990 and 2000, Africa lost 52 million hectares of forests: this amounts to a decrease of 0.8 per cent per year and 56 per cent of the global total (FAO 2003). It is estimated that 60 per cent of the tropical forest areas cleared in Africa as a whole between 1990 and 2000 were converted to permanent agricultural smallholdings (UNEP 2003). However, migration to urban areas is not inevitably destructive, nor does it necessarily lead to the formation or growth of dangerous and unhealthy slum areas (IOM 2005a). It is important to recognize the valuable role urbanization can play in stimulating the economy. The challenge lies in reversing the current pattern, and enhancing the efficiency of and the value derived from natural resource use.

Table 1: Population changes in Africa (million)
Sub-Region 1980 1990 2000 2010 2020
North Africa 109 140 170 209 239
East Africa 104 141 182 230 269
Southern Africa 70 90 113 129 150
Central Africa 54 74 98 127 164
West Africa 132 178 234 278 344
Total Africa 469 623 797 973 1 166

Source: FAO 2003. [Data from World Bank 2002; Africa Development Bank, 2000]

Over the last 20 years, Africa’s population has got younger, primarily as a result of the impact of HIV/AIDS, but also due to other setbacks. In 2003, more than 40 per cent of the region’s population was below the age of 15 years (FAO 2003). Given this, the youth are becoming increasingly important in natural resource management. The lack of employment and other livelihood opportunities, as well as setbacks in education, health and other capabilities, may mean that this generation will have increased natural resource dependence and pose new threats to the sustainability of marine and terrestrial ecosystems. Degraded environments may spur further social and economic conflicts and hardships.

Population growth presents a major challenge because of the patterns of production and consumption that shape the world, as well as the problems of pervasive poverty (Ness and Golay 1997). Population growth affects the natural resource base in many ways. First, it causes increased demand for food, water, arable land and other essential materials, such as firewood, in all areas. Second, expanded agricultural activities encourage encroachment into forest and woodlands. These consequences are more pronounced in the context of high levels of poverty. Third, the degradation of the natural resource base in turn impinges on the livelihoods of all, but particularly rural, communities. More small farmers are forced to work harder, often on shrinking farms on marginal land, to maintain household incomes (WCED 1987). The option of migration to new lands is virtually closed. In most cases, the impacts vary for men and women depending on the gender relations within the social unit (household, community, livelihood system) that regulates access to and control over resources and management responsibilities. Fourth, global population growth and the increasing demand for fossil fuels and other resources, also places new stress on Africa’s environment.

HIV/AIDS has had a significant impact on human capacity with severe economic, social and environmental consequences. Of the 45 most affected countries globally, 35 are in Africa. More than 25.8 million Africans are living with HIV/AIDS (UNAIDS and WHO 2005). Sub-Saharan Africa (SSA) is home to just 10 per cent of the global population but has more than 60 per cent of all people living with HIV (UNAIDS and WHO 2005). In SSA, the adult prevalence rate has gone down marginally from 7.3 per cent in 2003 to 7.2 per cent in 2005. There is considerable variation between countries. In Zimbabwe, the epidemic is declining (from 26 per cent prevalence among pregnant women in 2002 to 21 per cent in 2004) and there is some suggestion of a similar trend in Kenya, Uganda and Burkina Faso (UNAIDS and WHO 2005). For other countries the threat continues to grow and is particularly severe in South Africa, Nigeria and Mozambique. In Northern Africa, several countries are experiencing an increase in the prevalence of HIV/AIDS, including Algeria, Libya and Morocco (UNAIDS and WHO 2005). Life expectancy at birth in SSA has been reduced from 50 in 1990 to 46 in 2002 (World Bank 2005a) as shown in Annex 2, Table 1a: Sub-Saharan Africa Region Socioeconomic Indicators. The productive labour sector has been particularly hard hit by the high mortality in the 20-50 age bracket (FAO 2003). The loss of productive capacity is monumental (UNAIDS 2005, FAO 2003) and results in a decrease in disposable income, increased food insecurity and an increased dependency on the natural resource sector. At the same time, the loss of the most knowledgeable and productive age groups impacts on environmental managerial capacity. There is a significantly higher prevalence among women, due to unequal education and inequitable gender relations (UNAIDS and WHO 2005). The disproportionate impact of HIV/AIDS on women is particularly significant from an environmental perspective, as women in many parts of Africa assume major responsibility for natural resource stewardship (Oglethorpe and Gelman 2004).This demonstrates the importance of meeting MDG 3, to promote gender equity and empower women, not only from a rights perspective but also because of its environmental significance. The realization of this goal is closely related to MDG 2 on achieving universal primary education. Health, food security and environmental degradation are closely linked, and a negative change at any of these levels may have implications for the others.

Conflict affects population distribution and is a leading cause of internal migration. Africa now has more than 7.3 million refugees, 3 million more than in 1990 (FAO 2003). This places new pressures on environmental resources. In crisis situations, a large number of people may be displaced in a short period of time, causing a high level of environmental stress in the place where they are relocated due to increased demand and lack of preparedness. The depletion and deterioration of the areas in which camps are located are often related to the high demand for wood for shelters and energy. The inherent competition between local groups and forced migrants over access to natural resources may polarize social relations in refugee settlement areas and undermine opportunities for collaborative environmental management (Ertegun 2002). State-initiated resettlement initiatives to make way for development and conservation, such as dams and national parks, may also result in large-scale displacements that impact negatively on environmental resources and well-being more generally. Chapter 12: Environment for Peace and Regional Cooperation discusses the complex relationship between conflict and environmental change, and how the environment can be used as a vehicle to improve cooperation.

Migration has important implications for development, both positive and negative. Although it contributes to the transmission of disease, the introduction of alien species and the loss of skilled personnel, it may also bring new economic opportunities. The United Nations Economic Commission for Africa (UNECA) and the International Organization for Migration (IOM) estimate that between 1960 and 1975 more than 27 000 highly skilled Africans left the region for industrialized countries. This rose to 40 000 between 1975 and 1984 and then almost doubled by 1987, representing 30 per cent of the highly skilled labour stock (IOM 2005a). It is estimated that since 1990, at least 20 000 highly skilled and qualified persons leave the region annually (IOM 2005b). Although the loss of skilled people has negative impacts on the economy and other sectors, it also contributes to development through significant remittances and the enhancement of capacity of those that have left, in terms of skills and experience, potentially building an important human resource for Africa. Internal transnational migration in Africa is significant – the profile of such migration has changed from being unidirectional and permanent to being increasingly temporary, seasonal and circular. Africa has the most mobile populations in the world: there are many reasons for migration – one important motivation is to cope with ecological and economic problems (IOM 2005b).