1) Can the US really continue to expect such growth over the next 100 years? I was under the impression that the fertility rate of the united states was below replacement levels (perhaps near 2?), and that the immigrant population makes up the difference to bring our fertility rate above replacement levels (ie growth). With many states bringing in anti-immigration bills, I could see this possibly hurting US population growth.
2) Why does Brazil have an odd inflection point near 2050?
As to the main topic regarding Africa's population. I can't help but wonder if a more natural solution will find itself. With some many countries predicted to have a declining population, I can't help but think immigration will be the solution to fill the probable labor shortages caused by declining populations in nearby countries (China, India, Russia, according to the graph).