8.4 Human population carrying capacity

Significant ideas:

  • Human carrying capacity is difficult to quantify.
  • The EF is a model that makes it possible to determine whether human populations are living within carrying capacity.

Knowledge and understanding:

  1. Carrying capacity is the maximum number of a species, or “load”, that can be sustainably supported by a given area.
  2. It is possible to estimate the carrying capacity of an environment for a given species; however, this is problematic in the case of human populations for a number of reasons.
  3. An EF is the area of land and water required to support a defined human population at a given standard of living. The measure of an EF takes into account the area required to provide all the resources needed by the population, and the assimilation of all wastes.
  4. EF is a model used to estimate the demands that human populations place on the environment.
  5. EFs may vary significantly by country and by individual and include aspects such as lifestyle choices (EVS), productivity of food production systems, land use and industry. If the EF of a human population is greater than the land area available to it, this indicates that the population is unsustainable and exceeds the carrying capacity of that area.
  6. Degradation of the environment, together with the consumption of finite resources, is expected to limit human population growth.
  7. If human populations do not live sustainably, they will exceed carrying capacity and risk collapse.

Applications and skills:

  • Evaluate the application of carrying capacity to local and global human populations.
  • Compare and contrast the differences in the EF of two countries.
  • Evaluate how EVSs impact the EFs of individuals or populations.


  • Sustainability is the responsible use and management of global resources that allows natural regeneration and minimizes environmental damage.

Theory of knowledge:

  • Human carrying capacity is difficult to quantify and contains elements of subjective judgment. It has been claimed that historians cannot be unbiased—could the same be said of environmental scientists when making knowledge claims?


  • Sustainability (1.4)
  • Humans and pollution (1.5)
  • Access to fresh water (4.2)
  • Aquatic food production systems (4.3)
  • Terrestrial food production systems and food choices (5.2)
  • Energy choices and security (7.1)
  • Resource use in society (8.2)