We need food to live, but what that food does is to become digested into sugars that we oxidize into forms of energy that our body needs for its various processes. All of these processes were created and refined by over a few billion years of natural evolution.
Recently, that is, within the last half million years, we humans have added the refinement of what I have called Evish Selection. That is the ability, through the feedback cycles of evolution, of human women to select their mates for the qualities we call human. I assert that women are the primary force for creating advanced humans because males still choose their mates on the qualities of health, combined with the vigor that we call beauty. Artificial selection by females is future-oriented and goal-driven, in contrast to the males’ mate selection based on present observable qualities.
We have been an amazingly successful species so far, and we have brought under our direct and indirect control the majority of the physical body weight of all mammals. Only beef animals have a greater total weight than humans, then sheep, pigs, and goats. The total weight of elephants is small, and as a species, we outweigh them 250 to 1. A lot of tiny things outweigh us by far, but we all use energy to live, and those of us who live near the surface of Earth get our energy from the sun.
Except that we humans are now getting most of our energy from fossilized once-living things that have been converted to energy for one-time use: coal, oil, and natural gas. We get that food energy that’s created by plants indirectly by the use of fossil-fuel-powered machinery. It may be possible to drive our equipment using direct solar energy via lithium batteries. There is enough total lithium to create the needed batteries, but it may have a recycle limit as things tend to lose a little with every recycling of the base material.
Lithium isn’t polluting the atmosphere, as carbon-based fuels are presently doing, although it will probably develop some problems when used massively. It may be easier to construct a robot electric-driven farming technology than a carbon powered one because it is possible to create solar electric power locally, whenever the sun shines. Also, lead-acid batteries will work, and other kinds of batteries too. So we do have some options. These electric systems won’t be as productive in the short run, but purposely made solar cells might produce energy nearly forever, and well-constructed self-repairing robot machinery systems may ultimately be able to get food from the fields to one’s mouth without any human intervention. How soon will it be before Amazon will have a controlled-environment delivery box at every person’s home, or better yet a door in one’s wall which goes directly to a refrigerated compartment? Or ultimately into one’s mouth.
It isn’t really science fiction, it’s just a question of someone being willing to spend the money to make the system that will do it.