Here's an article about tabletop greenhouses controlled by a computer program:A Byte to Eat
Food computers "use up to 90 percent less water than traditional agriculture and can help reduce food waste." The ones built in the class showcased in this article are the size of a moving box and very cheap—the "computer" part of the system costs about $30.00.
These devices are too small, of course, to feed a household. However, they could allow people without yards or gardens to supplement their diets with home-grown vegetables. Furthermore, the design can be scaled up to the size of a warehouse.
In an essay written several decades ago, Isaac Asimov calculated how long it would take for the Earth to reach maximum sustainable population at the then-current rate of reproduction. In a surprisingly few centuries, he figured, the entire surface of the planet would reach the population density of Manhattan at noon on a weekday. (I don't remember whether this estimate includes paving over the oceans.) Setting aside the practical fact that this end point will never be reached, because societies would collapse long before then, how would all those people living in one continuous urban sprawl be fed? Agriculture on almost every rooftop would be needed. Asimov visualized giant algae vats producing the raw material for nutritive substances. The society of Harry Harrison's 1966 novel MAKE ROOM, MAKE ROOM, set in 1999, feeds the overcrowded planet with a protein substance called Soylent Green. (Interestingly, Harrison predicts this desperate condition in a world with 7 billion people. Global population today measures about 7.5 billion, and we're nowhere near those dire straits. Maybe there's hope.) Contrary to the movie (in which the authorities falsely claim that the product's base ingredient is plankton), Soylent Green in the book isn't "people." Thoughtful consideration makes it obvious that relying on cannibalism to feed everybody would make little sense. It's not efficient to sustain human livestock on food that people could eat directly. Any consumption of human meat would have to be sporadic and opportunistic, not the main source of nourishment. In the novel, Soylent Green is made of soybeans and lentils, a highly nutritious combination of proteins. Still, most likely, the majority of people would prefer "real food" if it could be cultivated in such an environment. And inexpensive computerized growing units like those in the tabletop greenhouse project could be part of the solution to the problem.
Not that I'd want to live in a world like that. As much as I would miss the modern conveniences I'm very attached to, I would almost prefer the low-tech future of S. M. Stirling's "Emberverse" series (beginning with DIES THE FIRE), whose inhabitants enjoy fresh, locally farmed foods as one compensation for the high-tech marvels they've lost.
Margaret L. CarterCarter's Crypt