That article is not particularly reassuring. Although the rate is declining in sub-saharan africa, it is very slow and seems to be stalling out. The example of Niger is particularly concerning:

[...] the shrinking arable land beset by frequent drought, is supporting a rapidly expanding population. [...] expected to grow from some 16 million today to 55 million in 2050, reaching 140 million by the end of the century

A 10x increase in population, decreasing farmland, and then add the effects of climate change on top...