According to models of demographic change derived from historical experience, it is estimated the global population will be between 9.5 and 13.3 billion people in 2100. The primary driver of global population growth is a projected increase in the population of Africa. The continent's current population of 1.2 billion people is expected to rise to between 3.4 billion and 5.6 billion people by the end of this century. "The continent's population growth is due to persistent high levels of fertility and the recent slowdown in the rate of fertility decline," Wilmoth noted.
The total fertility rate (TFR) has been declining in Africa over the past decade, but has been doing so at roughly one-quarter of the rate at which it declined in Asia, Latin America and the Caribbean in the 1970s. The results have important policy implications for governments across the globe. "Rapid population growth in high-fertility countries can exacerbate a range of existing problems - environmental, health, economic, governmental and social," said Wilmoth.