Driving forces are the mechanisms that allow change to occur. They can be thought of as clusters of shifts within society so great that they cause other significant shifts to take place. Driving forces set the initial course for development, but the complex regional system can rapidly change direction at critical thresholds of extreme turbulence and instability. Understanding the nature and interplay of driving forces is essential to developing scenarios. Driving forces are the departure points for looking at the future. They may operate with different magnitudes and directions than those of the initial stage, and they may emerge or disappear as circumstances dictate.
Current trends, on the other hand, are reflected in The State of the African Environment. Although they are not inevitably persistent, but evolve over time, they certainly condition the initial direction of economic, social and environmental change, and they may strongly influence even the long-term future. The driving forces control trends which are themselves influenced by social, economic and environmental conditions (Gallopin and others, 1997).
Africa witnessed dramatic population increase, from 221 million in 1950 to 785 million in 2000 (see Figure 4.11). Despite the fact that population growth rates have declined since the mid-1980s, Africa remains the world's fastest growing region, at an estimated 2.4 per cent per annum. However, future growth rates are expected to be lower. The region will attain an estimated population of 1 406 million by the year 2030 (UNDP 1999, 2000) (see also Figure 4.11). Rapid urbanization is also a main driving force, which is causing stresses in many African economies. With an average annual growth rate of 3.71 per cent (see Figure 4.12), Africa is the fastest urbanizing region of the world. Nevertheless, Africa is still very largely rural and agricultural. In 2000, the urbanization level was only 37.9 per cent, and it is projected to reach 54.5 per cent by 2030. Urban population is expected to grow from 297 million in 2000 to 766 million in 2030 (UNDP 1999).
Nonetheless, the problem of population in Africa is not related only to the population size, because Africa remains underpopulated by world standards. Rapid population growth entails challenges for the African countries to improve standards of living and to provide essential social services, including housing, transport, sanitation, health, education, job opportunities and security. It also limits the capacity of African countries to deal with the problem of poverty. Furthermore, rapid population growth rates are leading to political and social conflicts among different ethnic, religious and social groups.
The population age structure is heavily skewed towards young people, which generates tremendous demographic momentum. About 43 per cent of the population is below the age of 15 years, about 52 per cent is between the ages of 15 and 60 years, and 5 per cent are aged 60 years or older (UNDP 2000). The 15-24 age group numbered 149 million in 1998, constituting about 20 per cent of the total African population. This workforce bulge can be the basis for more investment, greater labour productivity and rapid economic development (Makinwa-Adebusoye, 2001). With such high population momentum, reflected in the rather high fertility rates, and in improving health and medical situations, it can only be expected that the population of African countries will rise to phenomenal heights and will continue to impact the environment in significant ways. Left unattended, these trends lead to great strains and undesirable consequences on the environment.
However, the rate of population increase is not uniform. Some areas experience higher than average rates of population increase, due both to higher intrinsic rates of growth and to immigration from other areas within a country, sub-region or the whole region. Such areas include town and cities, coastal regions, and the vicinity of lakes and rivers. Of these, the impact of population growth in urban areas is particularly important, because of the changes in lifestyle, consumption patterns and waste production that accompany urbanization. Conversely, some areas experience lower than average rates of population growth, due to below-average intrinsic rates of population increase and to emigration. Such areas include those in which there are conflicts or where there is severe environmental degradation.