Overpopulation by humans is real

The recent commentary in by Frances Kissling, Jothan Musinguzi and Peter Singer (“We must talk about overpopulation,” June 25) is timely and important. Human overpopulation needs much more exposure, discussion and action — now. Yet, as authors of the article wrote, it remains an unmentionable topic in most societies.

Although not generally agreed upon, climate change is widely and intensely considered and discussed today. A similar situation does not exist for human reproduction and overpopulation. It is a taboo — an inadmissible topic for social gatherings, as is criticism of people creating too many children. Reproduction is wrongly viewed a personal matter not to be judged by others.

With this quietness, it is difficult to assess the degree to which people comprehend overpopulation and its consequences. The causal factors of population dynamics? Population growth when many people produce five or more children? Impacts of large, rapidly growing populations? Replacement reproduction: Production of one child per person and tending to stabilize a population? Rates of fertility, death, migration, aging and longevity required to stabilize a population?

Fairly simple mathematical models answer those questions and illustrate dynamics of populations, including momentum that delays stabilization. Decision and subsequent action to stabilize the current 327 million people of the United States could require three to five generations and reach 600 million or more, depending upon rates of fertility, death, migration, aging and longevity. Significant immigration of highly reproductive people would significantly affect dynamics and success of a 2.1 births-per-female policy. The recent mandate of one child per female in China needed retention for a few generations before stabilization of its population well above the current 1.4 billion people.

Populations of nonhuman organisms generally are kept in check (in cyclical manner) by other, natural-enemy organisms through predation and parasitism. Human populations do not have predators except other humans. It is, therefore, incumbent upon humans to apply their supposed intelligence to concerted actions stabilizing the population at a responsible level. The current world population of 7.6 billion people (9.8 billion in 2050) is not responsible.

It is common for people to ask, “How many children do you have?” or say, “I have (number) children.” However, “have” is the wrong operator; the correct operator is “produce(d).” It matters not how many children you have but how many you have produced.

Significant but guarded public discussion of contraception exists, typically in the context of women’s reproductive health, almost never in regard to overpopulation. Unfortunately, women carry the burden of contraception; it is not expected of macho men. Significant contraceptive responsibility should be expected of men as well, perhaps exceeding that of women, because vasectomy is easy, safe and effective.

A major impediment to rational, effective action against overpopulation is the “humancentric,” anthropocentric, view of most societies, which permits humans to do without concern whatever they want to their biogeochemical environment. It denies importance of other organisms in the world scheme and that large human populations and their activities are deleterious to those organisms.

Many demographers and economists agonize over effects of reduced reproduction, stable, declining or aging population on economic growth, predicting doomsday rather than proposing, analyzing and promoting means to achieve economic growth and good lives under stable population. Talk and action against overpopulation is opposed by religions because their leaders recognize reproduction as a key to growth of followers and contraception as contrary to that objective.

Human overpopulation is real, and it is time for intense discussion and action upon it.