Dangers of Human Overpopulation

Ever since Thomas Malthus, we know that population growth is exponential, while the source of food from using the land is arithmetic. At the site worldmeter, it is reported that the world population in 1800 was 1 billion, in 1930 it became 2 billion, in 1974 it became 4 billion. Currently in 2021, it is nearly 7.9 billion.

The main and imminent danger from overpopulation and its effects is the destruction of the ecosystem. This means a disruption of climate, sea rises, pollution, species extinction.

Another effect is a depletion of resources — primarily food and water. And, as Jared Diamond noticed, the killings in Rwanda were not just due to ethnic hatred, but also due to a scarcity of subsistence land. [See, Jared Diamond, “Malthus in Africa: Rwanda’s Genocide,” Collapse, 2005]

Adding overpopulation and scarcity of resources to war and violence, the result is massive migrations of people into Europe and into the United States.

Today, on facebook, I was reminded of experiments done with mice and rats in overpopulated conditions (with adequate food and water) on behavior patterns which lead to extinction. I remember reading in the Scientific American in 1962, John Calhoun’s article “Population Density and Social Pathology.”

The one that today caught my attention is the experiment of John B. Calhoun; variously called “mouse utopia,” “behavioral sink,” and “universe 25.” Here is the account of the experiment:

See also: What Humans Can Learn from Calhoun’s Rodent Utopia