Should we aim to reduce the Earth population?

Some say we would do well to aim to reduce the Earth population, in part to reduce the load on natural resources and ecosystems. Are they right? This question is about the desirability of the aim, not about the means to achieve it; specifically, it is not about whether the state should create laws that limit the number of children people can have. There are multiple ways to achieve the end and state coercion is only one of them.

Other formulations:

  • Should we aim to reduce the world population?
  • Should we reduce the world population?
  • Should we reduce the Earth population?

We should aim to reduce the Earth populationEdit

Arguments forEdit

  •   Argument for The larger the population of a highly technical civilization, the greater the rate at which irreplaceable raw materials are being mined and exhausted. Reducing the population size would extend the lifespan of such a civilization.
  •   Argument for A smaller population has a smaller impact on ecosystems, and is better in reducing elimination of the richness of biological form such as species. Impact on species is a serious concern, with massive species extinction taking place.

Arguments againstEdit

  •   Argument against The more people on the Earth, the bigger the brain capacity to help solve problems and create abundance.
    •   Objection No brain capacity can work around the limits of a physical system, and the Earth is one.
    •   Objection If the information processing problem solving capacity is so important and given how computing capability has been growing exponentially for decades, and given how human population has exploded in the 20th century, why is it that we have not seen more astounding feats in the first two decades of the 21st centurry? What was achieved does not approach such breakthroughs as antibiotics, jet airplanes, and travel to the Moon. The added value of brain capacity seems overestimated.
  •   Argument against The larger the population of happy people, the greater the total happiness of the greatest number.
    •   Objection The total happiness of people is not the only morally significant concern. Biological heritage is also morally significant.
    •   Objection That may be rather temporary; the time dimension is key. It may well be that a steep rise to hights will be followed by a similar steep fall, whereas a much smaller population can be supportable for such a long time that, in some time frames, it will be larger than the steep-rise scenario.
  •   Argument against All species populations in nature expand when they can. To do otherwise would be unnatural and in violation of laws of nature.
    •   Objection Species population behavior is a natural tendency, not a law of nature analogous to a law of physics. Human populations can and have been consciously regulated. True laws of nature cannot be violated.
  •   Argument against This is not a concern. There is no such thing as a natural resource. The human resourcefulness is the greatest resource of them all.
    •   Objection Clearly untrue. Send the arguer to the Antarctic to learn about the natural resource of a favorable climate; or to Sahara, Tibet or Siberia.
  •   Argument against The Earth can sustain many more people: since the dire predictions in 1970ies, food has become much more abundant and death rates have fallen.
    •   Objection Such temporary trends cannot be reliably extrapolated to indefinite future. Specific predictions of when limits are going to be hit may fail, but it does not change the fact of the existence of the limits. The Earth is a physical system, not a piece of magic. Exponential growth in a physical system is very unsustainable, due to the rapid and for humans unintuitive exponentiality.
      •   Objection True, but the proposal is to reduce the population, not to stabilize it. The above argument is against growth of population, not specifically for reduction.
        •   Objection Fair enough. However, even stable non-growing population may have a poor sustainability whereas a much smaller one would have much better sustainability, possibly meeting e.g. species-protection targets.
  •   Argument against "The end of humanity will more likely come from collapsed birth rates than from climate change. The coming world population decline will not be reversed easily [...] It may well be necessary to ensure that global population numbers do not eventually fall below about seven billion if we are to avoid fading away."
    •   Objection That is far from obvious. In a situation of falling birth rates, there is going to be genetic variation driving differences in fertility and willingness to have children, and as a result of natural selection, genes that predispose to higher fertility and higher willingness to have children will start to dominate the gene pool in the middle run. Furthermore, once population declines by a huge amount, the ratio of population to sources easily available will greatly improve, creating conditions for reversal. The notion that once population starts falling, the trend is to be extrapolated indefinitely up to extinction is just another instance of foolish extrapolation from a single time series with no account for underlying forces and principles driving the series.

External linksEdit

For population reduction:

Against population reduction:

In both directions: