The world’s population has been increasing over time not only due to natural increase, but also because of the critically important medical advances made over time. In the 1950s, there were around 2.5 billion people (Haub, 2011) but today the population has increased to approximately 7 billion. It is projected to reach about 11 billion by the end of twenty-rst century. Although there have been predictions, Figure 27.1 shows three possible scenarios of world population levels based on xed fertility rates (United Nations Department of Economic and Social Affairs [DESA], 2013a,b). In 1950, about 0.18 billion people lived in Sub-Saharan Africa (SSA) but by 2012 it had reached approximately 0.9 billion. It is predicted that the population of SSA will reach 3.8 billion by the end of twenty-rst century (DESA, 2014). According to FAO (Food and Agricultural Organisation-United Nations), the population of SSA will grow faster than the rest of the world given the higher fertility and much improved health care; the death rates among children have dropped signicantly (Kohler, 2012). The average birth of the SubSaharan African mother is 5.2 children and in some countries the rate is signicantly larger such as Niger (7.6), which is the highest in the world today. Overall, the SSA fertility rate is about three times more than that of a European mother (1.6 children per women). Figure 27.2 shows world population in 2013 together with the projected population in 2050 in billions by region.