It's an increase in volume. As to exploiting more lands, I've not looked for data on that. While some of the increase would be used for other purposes, that in

It's an increase in volume. As to exploiting more lands, I've not looked for data on that. While some of the increase would be used for other purposes, that increase is still available for food production, and so that also boils down to an economic/moral/political issue, which was the main point: We can feed everyone; it's not a given that we will choose to feed everyone.