Also, about Africa: That's the only continent where birth rates remain really high today, and they have very far to go before the continent becomes uninabitable due to temperatures.
Anyway, my point was that UNLESS Africa continues to have such birth rates, the population seems to be falling sharply globally in the next century. In other words, the main assumption is that global pupulation is going down, with the Africa part only being a qualifier.
e.g. how is Africa going to have a high birth rate when it'll be largely inhabitable due to the high temperatures?
Also, what famine are you referring to and why does it not feature here: https://en.wikipedia.org/wiki/List_of_famines