Where we're heading?

World population unlikely to stop growing this century : Nature News & Comment: The authors calculate an 80% probability that the world population in 2100 will be between 9.6 billion and 12.3 billion, and a 95% probability that it will be between 9 billion and 13.2 billion (see chart above). They also predict that the odds are 70% that the population will keep growing throughout the century.

I wonder if climate change will be having an effect on African fertility (which is where the study says growth will be coming) by the second half of the century?  I mean, this sounds incredible:

Raftery and his colleagues project that Africa’s population will at
least triple by 2100, reaching 3.1 billion and possibly as high as 5.7
billion (see chart below). The population of Nigeria, currently 160
million people, could rise to 1.5 billion and overtake China as the
world’s most populous nation, says Raftery.