We don't have food scarcity; we have capitalism and carnism.
(ok, there's a few countries where there is legitimate food scarcity within their borders. But borders are fictional social constructs, and they could be fed if it wasn't for capitalism)
And if we ever did encounter a situation where the calories produced globally is less than the colories needed globally (caused by the "green" revolution, monocultures, factory farming, etc), then the solution is easy: stop diverting human food to factory farms and go back to polyculutres (eg 3 sisters) instead of horribly inefficient petro-dependent agriculture.