Overpopulation

[Anomalocaris]

I think everyone here is missing a big point. The immediate Malthusian trap is never about the theoretical carrying capacity of the world given some notional technological and organizational advancement that sounds plausible in the starry eyes of science fiction conventions. It's about the tendency of population growth to be exponential, and the tendency of the increase in technological capacity to be, in the long run, less than exponential. The immediate Malthusian trap closes when the population growth overtakes the CURRENT PORTION of the technology and resource curve.

The theoretical capacity where we do hydroponics in underground caves using fusion power lights and matter transmutation neutrients may or may not lie along SOME technological curve. But chance are our population curve will CROSS that technological curve long before the technological curve reaches the point where it can give us these things.

Also, even if we do reach the point where we can do these things so that we can technically support a population of certain size, if it cost more to use these techniques to support each additional person in the population than that person can return to the economy, then even that technically supportable population is still overpopulated.

The ideal population size is such that the economic cost of supporting one additional person exactly matches what the average additional person will return to the society. Then the population is at sustainable equilibrium. As technology advances and each person becomes more productive due to greater productive efficiency, then the size of the population can increase accordingly. If the population if higher than that, then the world would be richer if it were to depopulate. If the population is lower than that, then the world would be richer if people have more babies.

This is the standard of population and overpopulation, not whether vague technology can keep an additional personsalive at exorbitant cost to the rest of the society.