It boils down to lower yields, which mean we will not be feeding the world any longer. Africa will starve because of their incompetence in not being to farm at all and feed themselves. No excuse they can’t. They ran all the real farmers out and now they can’t even cultivate and make 40 acres work.
Africans are good at farming for their families. Enough for their families to eat. Aside from that, some of the best farming conditions in the world are at 6000ft in Kenya. The natives are still doing a good job there.