ABSTRACT
The world's human population is growing rapidly : currently estimated to be about 5.5 billion, it is projected to reach 10 billion by the year 2050. Its geographical distribution is also changing, with the fastest rates of growth occurring in less-developed countries. In Africa, for example, the total population increased five-fold since 1800. This is expected to rise to thirty-fold during this century. By contrast, while developed countries presently account for 25% of world's population, this is likely to decline to 15% by the early part of this century. Much of the projected growth in population will be centred on the world's cities-especially large cities (i.e. those with a population of greater than one million inhabitants). In this respect, the urban population, currently e timated to be about 2.3 billion people, is expected to double by 2020. Perhaps more significantly, it is predicted that 93 % of this increase will be associated with Third World cities. If this is the case, approximately two billion people will be added to these already congested urban areas during the lifetime of just a single generation. Not surprisingly, therefore, a recent report by the World Bank concluded that urban growth in developing countries i one of the most explosive problem for the beginning of the next century.
