Overpopulation continues to be a point of discussion in the world at large and is usually a part of whatever future is being told in a Science Fiction story. The number of people in the world and in the universe makes a difference on resources and on survivability. Throughout history we have been able to increase the capacity for human survival. At the same time what does this look like in the potential futures?
There are a few different options that I have seen in stories. One, is the expansion of humans beyond the usual limits, whether that is building up or expanding beyond the Earth. Another option is a little more sinister and that is control over the population, whether that is the release of a virus to culling the population or laws around procreation. Both of these are methods for dealing with overpopulation.
This kind of follows along with how humanity has dealt with overpopulation so far and that is to expand. One way this expansion is seen in Science Fiction is the increase in building and living space. In many stories the skyscrapers are taller and the living spaces smaller. Just think of the giant skyscraper apartment Bruce Willis lives in in the Fifth Element. The human population just keeps growing and we keep raising the limit for what can be handled.
The other expansion that is seen in stories is expansion into the stars and other planets. Many Science Fiction stories are about the way that humans have expanded into the stars and have populated a multitude of planets. All of this is about finding more living spaces and finding more resources in order for the human race to survive.
The other direction that can be taken to solve overpopulation is to control the population in some ways. One form of control is through rules and law about procreation. This can be done through limiting the number of children that people are allowed to have – like in Ender’s Game. This can be difficult to enforce unless you figure out someway to basically make people unable to have kids unless they are approved or make it that everyone adopts and no one has kids naturally. This would be a way to limit the population, but would require controlling the population.
The other option that is often presented in stories is one where the powerful recognize there is a resource issue in the world and decide that the population needs to be culled. Usually this entails introducing some sort of virus or plague that either will not kill everyone or that some people have be immunized against. This brings down the population numbers and helps save vital resources at a huge cost. This is another form of control over the population partly because it is a few deciding the good for the many and who has the right to make that decision?
Of course, control can backfire, like in The Restaurant at the End of the Universe, where the upper classes send away the lower classes from their planet – and then all die of a preventable disease because all the cleaning people are gone. But what stories are you thinking of?