Tigers and bears don’t farm, either.
Tech makes a big difference: If humans didn’t farm our population would be ~100 million; If we tile the world in greenhouses, and if we’re careful with our resources, we could have ~10 trillion.
Tech makes a big difference: If humans didn’t farm our population would be ~100 million; If we tile the world in greenhouses, and if we’re careful with our resources, we could have ~10 trillion.
Where? Physically, where? Compressed into tiny apartments all over the planet, like sardine cans?
I’d only be happy with that population level if we had a lot of Arcology-style mega-buildings to give each of us enough space and parkland, but that’s rather my point: tech enables the otherwise impossible.
63% of protein and 82% of calories come from 23% of agricultural land, which is itself 51% of habitable land, which is itself 71% of land, which is 29% of the surface. That agricultural land mostly isn’t greenhouses, which are far more productive than open ground, but even greenhouses are not the most productive food sources we know how to make.
Even without changing the ratio of farmland where greenhouses or better are used (a cunning trick if you can do it, given you’d need something like a greenhouse or aeroponics to turn uninhabitable land into farm land), that takes us up to 7.7-fold increase in carrying capacity for pure land use and 26.6-fold if you add in potential aquaculture.
Most of us don’t have a reason to care more about efficient use of farmland. Some places do, which is why greenhouses, hydroponics, and aeroponics exist at all, but most of us don’t.
And then, separately from greenhouses (probably before but I don’t know how to account for it), there’s better crop choices, and finally GM crops.