Let’s not oversimplify by blaming everything on pollution—we can do better intellectually. Multi-generational disconnection from nature may erode our very humanity, including the ability to reproduce.
I know you mean something broader than just sperm count, but it is worth pointing out that sperm count isn't usually seen as the direct cause of the lower fertility/rate of pregnancy. The direct cause is likely contraception. Right? Now, I totally believe that crampted and ennui-enducing living makes people not want children though.
My understanding is that the sperm count does not crucially matter for fertility as long as it is well above a certain threshold. I liked the notion of "over-engineering" that Jeremy Grantham applied to this situation:
"there was a 60% [decline] from 1945 to 2021 when we were talking about it. The 60% drop in the sperm count in the developed world, and you can say, and China. And what that means is it's real trouble now.
We were over-engineered, I like to say, like a Victorian bridge. So dropping to almost 40%, 50% [of the original sperm count] didn't matter. But beyond that, it suddenly started to matter a lot. And we have gone from a rounding era of young couples having trouble getting pregnant to about 15%."
COVID "vaccines" are devastating to testes, ovaries and the gametes within them.
Bonus Points!
:-/
COVID-19 mRNA Shots Destroy Over 60% of Women’s Non-Renewable Egg Supply
New study finds rats injected intramuscularly with human-equivalent mRNA doses suffered irreversible loss of primordial follicles — the foundation of fertility.
Extremely interesting read, thank you for posting.
While reading I couldn't help but think of William Catton Jr.'s argument in Overshoot that when a species is in ecological overshoot (that I would argue humans seem to be in), their fertility rates are negatively impacted due to various environmental stressors--'pollution' and 'urbanisation' being two of these.
I agree with this perspective. It is interesting in this regard that cities in human history appear to have been a demographic sink -- and as such they could only be sustained and enlarged by immigration. I gave some links in my response to Ugo and this is another about Mesopotapian cities
I am sorry, Anastassia, but I have to disagree with your interpretation. Not that chatGPT is wrong, but what should count is not the total number of people living in cities, but -- if anything -- how densely populated cities are. And, in our times, cities are less dense than they were in -- say -- Medieval times. Humans have been living in densely packed towns from Sumerian times, but that didn't prevent them from reproducing. Calhoun experiments, in my opinion, are not applicable to humans. Mice do not live in cities, never did. We, instead, have been living in cities for 5000 years, at least. Anyway, there is a whole chapter on Calhoun experiment in my upcoming book "The End of Population Growth" -- I'll cite your results!
Ugo, while I disagree with some of your statements, your critical comments are most valuable and welcome. Let me clarify where our perspectives diverge.
1. “We, instead, have been living in cities for 5,000 years, at least.”
Only a small proportion of humans lived in large cities at any time—for the simple reason that most people had to work in the fields to produce food. For example, in the Roman Empire, at best, around 10% of the population lived in major urban centers.
2. “Humans have been living in densely packed towns since Sumerian times, but that didn’t prevent them from reproducing.”
In all pre-industrial eras, larger cities were effectively demographic sinks, where mortality consistently exceeded fertility due to disease and other stressors -- indicating that such high densities are biologically unsustainable for our species. These cities were sustained only by constant immigration from rural areas. If humanity had relied solely on cities for reproduction, we would have long since disappeared.
3. “What should count is not the total number of people living in cities, but—if anything—how densely populated cities are.”
What should count—for what purpose? Most pre-industrial “cities” were small in absolute terms, ensuring close proximity to the natural environment.
Take Pompeii, for instance: it had an estimated population of 11,132 and a density of 16,615 people per sq. km. That’s less than one square kilometer in area—meaning green space was always just a few hundred meters away. Children could easily access nature and develop in healthier surroundings.
4. Rome, which was much larger in scale, suffered from many of the same problems that plague modern cities.
Mortality exceeded fertility, but also fertility itself was diminished relative to the rest of the population. Otherwise, there would have been no need for Augustus—and subsequent emperors—to enact laws penalizing childlessness and incentivizing larger families.
5. Finally, Calhoun’s findings point to a unique combination of two modern anomalies: unnaturally high population density and unprecedented longevity.
This combination is something no human society had faced before. Not only are today’s young people “locked in space,” they are also “locked in time”—unable to step into the social roles of family founders and decision-makers, roles that were traditionally assumed much earlier in life when life expectancy was lower.
You can't fool nature. Having overcome mortality, we are now facing a collapse in fertility—and cities, as ever, remain demographic sinks.
I’ve found the following sources particularly insightful:
Knauft, B. M. (1987). Divergence between cultural success and reproductive fitness in preindustrial cities. Cultural Anthropology, 2(1), 94–114. https://www.jstor.org/stable/656398
Anastasia, thanks for interesting perspective. I believe more in bio-socio-cultural factors than the decreasing sperm count. I wrote something about it recently, that mentions urbanisation as one of the factors for declining population. "In my view, there are huge societal changes underlying the falling birth rate. The world is increasingly “full”. There is less space for people (and in particular where people aggregate the most, in the big cities), we are running out of resources (or it becomes more and more difficult to access them), we are undermining the ecosystems that we need to thrive and the capacity of the biosphere to take care of all our emissions has reached several limits (global warming is but one such). Perhaps, people feel that in some subconscious way, and that feeling ultimately also affect the desire to procreate?"
and
"Many people don’t see their life as part of the bigger biological and social context. Reproduction is seen as an individual choice and not an essential part of being a biological organism. One could argue that one of the main aspects of sustainability is to ensure the continued existence of the human species***. Not caring for the future of humanity can in this way be seen as the ultimate victory for modernism and as such it can also be the seed of its death."
It's all uneven. Idividuals, especially highly mobile individuals, may adapt. Eating junk food is bad for sperm count. I never ate much junk food. I was raised to eat healthfully by my mother and grandmother.
I had an exemplary sperm count and motility, even in the stress of med school, where it was frequently evaluated in my role as a paid genetic donor. My sperm was the standard by which many other lesser men were judged and often found lacking. I bike commuted to med school about 14 miles each way, so I was outdoors biking by the bayou even if I was sleepless and tired. We had 4 healthy kids in 4 years. They are healthy adults.
Be healthy. Have meaning. Seek truth.
I got a vasectomy when our fourth child was gestating, got it from my next door neighbor. He did a good job. He was sympathetic because he had just had one.
My sperm count has been zero since 1992.
I'm a has-been, but I grow vegetables and ride a bike.
I am late to the party but would like to make some comments: Before creating hypotheses, we should look at the facts, and some of these are incompatible with "urbanisation" as the only or main driver of the fertility crisis: In Switzerland sperm counts and quality are especially affected in rural and agricultural regions, its the farmers' boys who are just NOT living in urban or crowded areas. Likewise, the testosterone decline is especially marked in the American Midwest, the "breadbasket of the nation", which is less densely populated than the coasts. In both cases this might point to pesticides. See this impressive graphics: https://testosteronedecline.com/wp-content/uploads/2022/03/USA-testosterone-moving-from-before-1985-to-current-animation.gif
Also, one cannot ignore the well-documented damaging effect of phthalates (from plastic packaging of food) on testicular development. These are again independent of population density and urbanisation. Endocrinologists have warned for years that there are no safe upper limits for these endocrine disruptors, but regulatory authorities still base themselves on the outdated knowledge from 30 years ago.
Population decline cannot be explained by declining sperm counts, these still being largely sufficient to produce babies. However, if you lower testosterone, this takes away potency and attraction between sexes (also in women!), lowers sexual activity and therefore most probably also the production of babies.
I know you mean something broader than just sperm count, but it is worth pointing out that sperm count isn't usually seen as the direct cause of the lower fertility/rate of pregnancy. The direct cause is likely contraception. Right? Now, I totally believe that crampted and ennui-enducing living makes people not want children though.
My understanding is that the sperm count does not crucially matter for fertility as long as it is well above a certain threshold. I liked the notion of "over-engineering" that Jeremy Grantham applied to this situation:
"there was a 60% [decline] from 1945 to 2021 when we were talking about it. The 60% drop in the sperm count in the developed world, and you can say, and China. And what that means is it's real trouble now.
We were over-engineered, I like to say, like a Victorian bridge. So dropping to almost 40%, 50% [of the original sperm count] didn't matter. But beyond that, it suddenly started to matter a lot. And we have gone from a rounding era of young couples having trouble getting pregnant to about 15%."
https://www.youtube.com/watch?v=cTvN9iFJ0fY
COVID "vaccines" are devastating to testes, ovaries and the gametes within them.
Bonus Points!
:-/
COVID-19 mRNA Shots Destroy Over 60% of Women’s Non-Renewable Egg Supply
New study finds rats injected intramuscularly with human-equivalent mRNA doses suffered irreversible loss of primordial follicles — the foundation of fertility.
https://www.thefocalpoints.com/p/breaking-covid-19-mrna-shots-destroy
Extremely interesting read, thank you for posting.
While reading I couldn't help but think of William Catton Jr.'s argument in Overshoot that when a species is in ecological overshoot (that I would argue humans seem to be in), their fertility rates are negatively impacted due to various environmental stressors--'pollution' and 'urbanisation' being two of these.
I agree with this perspective. It is interesting in this regard that cities in human history appear to have been a demographic sink -- and as such they could only be sustained and enlarged by immigration. I gave some links in my response to Ugo and this is another about Mesopotapian cities
Algaze, G. (2018). Entropic cities: The paradox of urbanism in ancient Mesopotamia. Current anthropology, 59(1), 23-54. https://www.journals.uchicago.edu/doi/abs/10.1086/695983
Nevertheless what cities did reproduce was cultural knowledge.
Fascinating. Thankyou
I am sorry, Anastassia, but I have to disagree with your interpretation. Not that chatGPT is wrong, but what should count is not the total number of people living in cities, but -- if anything -- how densely populated cities are. And, in our times, cities are less dense than they were in -- say -- Medieval times. Humans have been living in densely packed towns from Sumerian times, but that didn't prevent them from reproducing. Calhoun experiments, in my opinion, are not applicable to humans. Mice do not live in cities, never did. We, instead, have been living in cities for 5000 years, at least. Anyway, there is a whole chapter on Calhoun experiment in my upcoming book "The End of Population Growth" -- I'll cite your results!
Ugo, while I disagree with some of your statements, your critical comments are most valuable and welcome. Let me clarify where our perspectives diverge.
1. “We, instead, have been living in cities for 5,000 years, at least.”
Only a small proportion of humans lived in large cities at any time—for the simple reason that most people had to work in the fields to produce food. For example, in the Roman Empire, at best, around 10% of the population lived in major urban centers.
2. “Humans have been living in densely packed towns since Sumerian times, but that didn’t prevent them from reproducing.”
In all pre-industrial eras, larger cities were effectively demographic sinks, where mortality consistently exceeded fertility due to disease and other stressors -- indicating that such high densities are biologically unsustainable for our species. These cities were sustained only by constant immigration from rural areas. If humanity had relied solely on cities for reproduction, we would have long since disappeared.
3. “What should count is not the total number of people living in cities, but—if anything—how densely populated cities are.”
What should count—for what purpose? Most pre-industrial “cities” were small in absolute terms, ensuring close proximity to the natural environment.
Take Pompeii, for instance: it had an estimated population of 11,132 and a density of 16,615 people per sq. km. That’s less than one square kilometer in area—meaning green space was always just a few hundred meters away. Children could easily access nature and develop in healthier surroundings.
4. Rome, which was much larger in scale, suffered from many of the same problems that plague modern cities.
Mortality exceeded fertility, but also fertility itself was diminished relative to the rest of the population. Otherwise, there would have been no need for Augustus—and subsequent emperors—to enact laws penalizing childlessness and incentivizing larger families.
5. Finally, Calhoun’s findings point to a unique combination of two modern anomalies: unnaturally high population density and unprecedented longevity.
This combination is something no human society had faced before. Not only are today’s young people “locked in space,” they are also “locked in time”—unable to step into the social roles of family founders and decision-makers, roles that were traditionally assumed much earlier in life when life expectancy was lower.
You can't fool nature. Having overcome mortality, we are now facing a collapse in fertility—and cities, as ever, remain demographic sinks.
I’ve found the following sources particularly insightful:
Storey, G. R. (1997). The population of ancient Rome. Antiquity, 71(274), 966–978. https://doi.org/10.1017/S0003598X00085859
Knauft, B. M. (1987). Divergence between cultural success and reproductive fitness in preindustrial cities. Cultural Anthropology, 2(1), 94–114. https://www.jstor.org/stable/656398
Anastasia, thanks for interesting perspective. I believe more in bio-socio-cultural factors than the decreasing sperm count. I wrote something about it recently, that mentions urbanisation as one of the factors for declining population. "In my view, there are huge societal changes underlying the falling birth rate. The world is increasingly “full”. There is less space for people (and in particular where people aggregate the most, in the big cities), we are running out of resources (or it becomes more and more difficult to access them), we are undermining the ecosystems that we need to thrive and the capacity of the biosphere to take care of all our emissions has reached several limits (global warming is but one such). Perhaps, people feel that in some subconscious way, and that feeling ultimately also affect the desire to procreate?"
and
"Many people don’t see their life as part of the bigger biological and social context. Reproduction is seen as an individual choice and not an essential part of being a biological organism. One could argue that one of the main aspects of sustainability is to ensure the continued existence of the human species***. Not caring for the future of humanity can in this way be seen as the ultimate victory for modernism and as such it can also be the seed of its death."
https://gardenearth.substack.com/p/is-modernity-killing-itself?
It's all uneven. Idividuals, especially highly mobile individuals, may adapt. Eating junk food is bad for sperm count. I never ate much junk food. I was raised to eat healthfully by my mother and grandmother.
I had an exemplary sperm count and motility, even in the stress of med school, where it was frequently evaluated in my role as a paid genetic donor. My sperm was the standard by which many other lesser men were judged and often found lacking. I bike commuted to med school about 14 miles each way, so I was outdoors biking by the bayou even if I was sleepless and tired. We had 4 healthy kids in 4 years. They are healthy adults.
Be healthy. Have meaning. Seek truth.
I got a vasectomy when our fourth child was gestating, got it from my next door neighbor. He did a good job. He was sympathetic because he had just had one.
My sperm count has been zero since 1992.
I'm a has-been, but I grow vegetables and ride a bike.
I am late to the party but would like to make some comments: Before creating hypotheses, we should look at the facts, and some of these are incompatible with "urbanisation" as the only or main driver of the fertility crisis: In Switzerland sperm counts and quality are especially affected in rural and agricultural regions, its the farmers' boys who are just NOT living in urban or crowded areas. Likewise, the testosterone decline is especially marked in the American Midwest, the "breadbasket of the nation", which is less densely populated than the coasts. In both cases this might point to pesticides. See this impressive graphics: https://testosteronedecline.com/wp-content/uploads/2022/03/USA-testosterone-moving-from-before-1985-to-current-animation.gif
Also, one cannot ignore the well-documented damaging effect of phthalates (from plastic packaging of food) on testicular development. These are again independent of population density and urbanisation. Endocrinologists have warned for years that there are no safe upper limits for these endocrine disruptors, but regulatory authorities still base themselves on the outdated knowledge from 30 years ago.
Population decline cannot be explained by declining sperm counts, these still being largely sufficient to produce babies. However, if you lower testosterone, this takes away potency and attraction between sexes (also in women!), lowers sexual activity and therefore most probably also the production of babies.
I am currently summarising these effects in a series of substack posts, some already published, the others due to appear in the next weeks: https://lukasfierz.substack.com/p/castrated-in-the-womb