# Population decline

Population decline is a reduction in any species' population.

## Quotes

* The ultimate measure of human success is not production but reproduction. Economic productivity and profit are means to reproductive ends, not ends in themselves.
** Pierre L. van den Berghe, The Ethnic Phenomenon (1981), Bloomsbury Academic
* On a farm, a child is an investment—an extra pair of hands to milk the cow, or shoulders to work the fields. But in a city a child is a liability, just another mouth to feed.
** Darrell Bricker & John Ibbitson, Empty Planet: The Shock of Global Population Decline (2019), Robinson
* With populations aging and declining almost everywhere, countries may one day be competing for immigrants.
** Darrell Bricker & John Ibbitson, Empty Planet: The Shock of Global Population Decline (2019), Robinson
* In the 1990s, as the consequences of a chronically low birth rate begin to sink in, Ottawa opened the floodgates, inviting 250,000 immigrants a year to come to Canada.
** Darrell Bricker & John Ibbitson, Empty Planet: The Shock of Global Population Decline (2019), Robinson
* Among millennials, especially, the fertility rate is very low. Between 2007 and 2012, the birth rate among Americans who came of age after 2000 dropped by 15 percent, to the lowest birth rate ever recorded in the United States: 0.95, less than one baby for every mother.
** Darrell Bricker & John Ibbitson, Empty Planet: The Shock of Global Population Decline (2019), Robinson
* All of this is completely, utterly wrong. The great defining event of the twenty-first century—one of the great defining events in human history—will occur in three decades, give or take, when the global population starts to decline. Once that decline begins, it will never end. We do not face the challenge of a population bomb but of a population bust—a relentless, generation-after-generation culling of the human herd. Nothing like this has ever happened before.
** Darrell Bricker & John Ibbitson, Empty Planet: The Shock of Global Population Decline (2019), Robinson
* There are more forty-year-old women than there are thirty-year-old women, who outnumber twenty-year-old women. That's what makes population decline so implacable; once it sets in, it’s virtually impossible to stop, because every year there are fewer women of child-bearing age than there were the year before.
** Darrell Bricker & John Ibbitson, Empty Planet: The Shock of Global Population Decline (2019), Robinson
* The low-fertility trap, once in place, is irreversible.
** Darrell Bricker & John Ibbitson, Empty Planet: The Shock of Global Population Decline (2019), Robinson
* World population may shrink for multiple reasons, including poor nutrition and epidemics.
** Gail Tverberg, "The world has a major crude oil problem; expect conflict ahead" (April 21, 2022)
* We cannot know in advance exactly how the economy will shrink back its energy consumption, besides regionalization and pushing the US dollar (at least partially) out of being the reserve currency. Some other areas where the physics of the economy might force cutbacks include the following: Vacation travel; Banks, insurance companies, pension programs (much less needed); The use of financial leverage of all kinds; Governmental programs providing payments to those not actively in the workforce (such as pensions, unemployment insurance, disability payments); Higher education programs (many graduates today cannot get jobs that pay for the high cost of their educations); Extensive healthcare programs, especially for people who have no hope of ever re-entering the workforce. In fact, the population may start to fall because of epidemics, poor health, or even too little food. With fewer people, limited energy supply will go further.
** Gail Tverberg, "2023: Expect a financial crash followed by major energy-related changes" (January 9, 2023)
* In nature, population overshoot is usually remedied by a higher die-off rate, not a lower birth rate.
** Mike Roberts, "What Can Antinatalism Achieve?" (August 8, 2024)
* A lot of technologies have been utilised in storing food or growing more of it. And we know that increased access to food increases population size. The reverse is also true, of course, so we should expect population to fall as harvests come under stress from the effects of climate change. […] At every possible fork in the path of the future, humans, generally, will always choose the route that gives them more convenience or more comfort. Only when none of the possible routes provide that option will humans start down the contraction and lower energy path.
** Mike Roberts, "The inevitability of our predicament" (September 14, 2024)
* The first dramatic effect of food shortage is upon fertility.
** Arthur Wynn, Margaret Wynn. "The effects of food shortage on human reproduction." Nutrition and Health, Volume 9, N° 1 (January 1993).
* Detritus ecosystems are not uncommon. When nutrients from decaying autumn leaves on land are carried by runoff from melting snows into a pond, their consumption by algae in the pond may be checked until springtime by the low winter temperatures that keep the algae from growing. When warm weather arrives, the inflow of nutrients may already be largely complete for the year. The algal population, unable to plan ahead, explodes in the halcyon days of spring in an irruption or bloom that soon exhausts the finite legacy of sustenance materials. This algal Age of Exuberance lasts only a few weeks. Long before the seasonal cycle can bring in more detritus, there is a massive die-off of these innocently incautious and exuberant organisms. Their "age of overpopulation" is very brief, and its sequel is swift and inescapable.
** William R. Catton, Overshoot (1980), p. 168
* … the coming century contains a population problem that should be of great concern because of the ongoing momentum that will cause global population to crest just as global population growth hits its nadir. This means that the resource scarcity problem foreseen by Malthus will become most severe just as the technological solutions provided in the past become most costly to produce. Ironically, the population problem foreseen by Malthus is one where declining population growth rates may be the primary reason for substantial increases in global resource scarcity.
** Pedro Naso, Timothy Swanson, "How declining population growth might portend a future of increasing resource scarcity," VoxEU, Centre for Economic Policy Research (May 29, 2023).
* The attrition of global populations by disease may be unavoidable. Some readers may regard it as the inevitable revenge of nature against the hubris of a human species arrogantly exceeding the carrying capacity of its habitat. Some may regard it as a moral victory against wickedness. Some may view it in the therapeutic mode as a positive development for the health of the planet. Many self-conscious "humanists" have militated for the goal of reducing population growth—though most of them would have probably preferred widespread birth control to a die-off. But that kind of thinking might have been just another product of the narcotic comfort of cheap oil, as merely stabilizing the earth's population at current levels (or even 1968 levels) would arguably still have left humanity beyond the earth's carrying capacity. Apart from these issues of attitude and ethics, however, a major decline in world population, or change in demographic profiles, is apt to have profound and strange repercussions on everyday life.
** James Howard Kunstler, The Long Emergency (2005), Chapter 5, p. 178.
* One doesn’t even need a model to put the main pieces together: human population has been significantly inflated by extensive exploitation of a non-renewable finite resource. Because the declining availability/use of that resource is inevitable (and likely near-at-hand), it stands to reason that present levels of population will be unsustainable—and that the necessary transition down from an overstuffed population will be very difficult to bear. The world left in the wake of our binge will be less able to support us than the one we inherited, exacerbating the hardship.
** Tom Murphy, "Finite Feeding Frenzy," Do the Math, University of California, San Diego (December 5, 2022)
* Humans, like many mammals, have hormonal and genetic mechanisms that help control procreation. In good times females reach puberty earlier, and their chances of getting pregnant are a bit higher. In bad times puberty is late and fertility decreases.
** Yuval Noah Harari, Sapiens (2014), Part II: "The agricultural revolution," Chapter 5: "History's biggest fraud".
* A basic understanding of overshoot reveals that our modern industrial way of life is unsustainable at anything like its current scale and intensity. Whether as a result of pollution or resource depletion, human population and per-capita consumption will peak and start to decline, most likely during the next decade or two. But it gets worse: during our brief binge of industrialism we humans have found strategies (including corporate globalization and the proliferation of credit and debt in a widening variety of forms) to maximize consumption in the short term; when these strategies inevitably falter, the result will likely be an even faster decline in population and consumption than might be expected on the basis of ecological factors alone.
** Richard Heinberg, "MuseLetter #381: Environmental-Political Collapse Accelerates" (December 18, 2024)
* … technology use harnesses far more energy and materials than we could ever manage without it, and while doing so may make our lives much easier and more comfortable, it comes at the cost of increasing ecological overshoot. As we increase overshoot, we concomitantly increase all the symptom predicaments that overshoot causes. Technology use also has another nasty side effect. It reduces and/or eliminates negative feedbacks which once kept our numbers in check. Many diseases we once suffered from like smallpox, measles, whooping cough, tetanus, etc. have been temporarily eliminated by the technological development of vaccines. Our medical industry has also wiped out many other diseases through proper sanitation, use of antiseptics, anesthetics (allowing surgeries to correct most internal ailments), antibiotics, antifungals, and antivirals to kill or prevent many diseases, and many other innovations that allow us to live better, more comfortable lives. The development of indoor plumbing, electrical systems, heating and air conditioning systems, insulation, refrigerators and freezers, and cooking devices all allow us to accomplish daily tasks either much easier or provide more comfort to us by regulating temperature and humidity levels in our living spaces. Therefore, technology use reduces or removes negative feedback thereby promoting population growth which also promotes technology growth. However, in terms of reducing overshoot (and symptom predicaments such as climate change, energy and resource decline, pollution loading, and biodiversity decline), technology use is maladaptive. This will become painfully clear as time moves forward when more or different technology does not actually solve overshoot. Population decline is what will actually work to reduce overshoot, caused by the failure of our agricultural systems, increased disease caused by antimicrobial resistance and new viruses emerging, and increased failures of infrastructural systems caused by extreme weather events. Reduced technology use will be facilitated by this mechanism, and ALL species wind up experiencing die-off whether they use technology or not.
** Erik Michaels, "How Did We Get Here?" (July 19, 2023).
* Peak [living] human population will… lag… peak [extraction of] oil and peak [extraction of other] mineral resources until these conditions express themselves as food shortages. This means that the human population will continue to rise for a while, even as we begin to encounter these… limits. It’s not possible to estimate how much the [living] population will increase because the relationship between energy and mineral resources and food production is a very fragile equation, subject to any number of discontinuities. To these, add the complications of weather disasters arising from climate change, including drought, the spread of plant diseases, and so forth. This lagging further rise in [the living] human population will only make the inevitable contraction more acute once food shortages begin. […] We're putting a strain on everything the earth has to offer us. While the combination of peak stuff and… billion[s of] [living] humans is forcing the issue, ...the truth is that circumstances will now determine what happens, not policies or personalities. […] Population overshoot is therefore unlikely to yield to management. Rather, the usual suspects will enter the scene and do their thing: starvation, disease, […] violence […] [and] death […].
** James Howard Kunstler, Too Much Magic (2012), Chapter 1, p. 10.
* People who believe that a stable population can live in balance with the productive capacity of the environment may see a slowdown in the growth of population and energy consumption as evidence of approaching equilibrium. But when one understands the process that has been responsible for population growth [the extraction and use of fossil fuels], it becomes clear that an end to growth is the beginning of collapse.
** David Price, "Energy and human evolution", Population and environment, Vol. 16, No. 4 (1995)
* Operative mechanisms in the collapse of the human population will be starvation, social strife, and disease. These major disasters were recognized long before Malthus and have been represented in western culture as horsemen of the apocalypse. They are all consequences of scarce resources and dense population.
** Ibid.
* Starvation, social strife, and disease interact in complex ways. If famine were the sole mechanism of collapse, the species might become extinct quite suddenly. A population that grows in response to abundant but finite resources, like the reindeer of St. Matthew Island, tends to exhaust these resources completely. By the time individuals discover that remaining resources will not be adequate for the next generation, the next generation has already been born. And in its struggle to survive, the last generation uses up every scrap, so that nothing remains that would sustain even a small population. But famine seldom acts alone. It is exacerbated by social strife, which interferes with the production and delivery of food. And it weakens the natural defenses by which organisms fight off disease.
** Ibid.

## See also

* Eugenics
* Children
* Overpopulation