World Population Decline

Well . . . humans, in general, are not that much different from other species of animals in terms of resources and reproductive rates. I guess I shouldn't be surprised.

I'm not sure I really believe the population is shrinking, but I could believe the birth rate is slowing. However, the author's points about models is very germane. Just because a model had been accurate in the past does not guarantee that the model will be accurate in the future.

There are certainly other physical models for highly complex systems whose ability to predict the future has been lackluster at best.

..."Basically, countries with birth rates above 1.6 or 1.7 children per woman experienced fertility declines. Countries with birth rates below that saw more stability or even increases. What we appear to be seeing is a global convergence around fertility rates of 1.6 or 1.7 children.

This is not just a rich-world phenomenon. Birth rates in Mexico are around 1.9 to 2 kids per woman, so below the rate needed to sustain Mexico’s current population levels. Brazil’s birth rate is even lower, at 1.75, similar to Colombia’s at 1.77. Costa Rica is even lower, at 1.66. El Salvador, Argentina, and Venezuela are all just barely “breaking even” demographically. Other countries like Guatemala are higher but falling fast.

Across the Pacific, Sri Lanka, Bangladesh, and India are all around 2 or 2.2 kids per woman, while Malaysia has fallen to about 1.8. Thailand is even lower, at 1.5 kids per woman. Even Muslim countries like Turkey (2), Iran (1.8), and Tunisia (2.1) have near-replacement fertility, with speedy declines still ongoing."...

https://ifstudies.org/blog/a-new-normal-an-updated-look-at-fertility-trends-across-the-globe

Interesting data.

Kill joy for the Social Security pyramid scheme.

I did my part participated in reversing the trend. 4.0

I'm offsetting you just 1.0...but it wasn't for lack of trying...

..."The UN as of 2017 predicts a decline of global population growth rate from +1.0% in 2020 to +0.5% in 2050 and to +0.1% in 2100. ... Randers' "most likely scenario" predicts a peak in the world population in the early 2040s at about 8.1 billion people, followed by decline."...

https://en.wikipedia.org/wiki/Projections_of_population_growth

The data presented is based on research of real world population fertility rates, not projections from computer models....like the above UN est..

A decline in the population growth rate is not the same as a decline in population. Applying the brakes on a car moving forward on a flat road decreases the velocity of the car moving forward. It does not make the car move backwards.

Unlike my vehicular analogy, population growth does have a separate negative vector (mortality) applied. So a birth rate must exceed the mortality rate for actual population growth to occur.

Also the specious growth or decline number of 2 births per child bearing woman is not really a good benchmark. Many a solitary man has fertilized multiple women over a lifetime.

The point is that the UN est is based on computer models.....The OP video is based on real world research, and current....Fertility rates are based on the average number of children born to women, if the average for a population is below ~2.1 children per woman, the population is said to be in decline...Although the models show a worldwide decline in fertility rates, this research shows that it's happening faster than was projected by the models....

I'm sure that the UN does have computer models to project out to the future. However, the reason the chart I presented from the 2017 UN report stops at 2015 is because it's not data from a model. That tallied result puts the birth rate at 2.5 in 2015.

You presented a Wikipedia article on population growth projections and then criticised them for being from a computer model. (A classic straw-man false argument.) Naturally all projections into the future have to come from a model in one form or another.

Getting back to the OP video, I tried and failed to find any other sources that corroborate the videos claim of a declining population. I even provided links to my searches. (I'm not trying to hide anything.) I did repeatedly find that the rate of population growth is declining. If nothing else changes I expect the global population to actually one day decline but it hasn't yet.

My point is that a true revelatory measurement that differs from expectations would likely spawn multiple confirming remeasurements. I do not see them. They might be coming but they clearly are not here now.

I think I posted another source in #2....How many do you want? The population increase is mostly attributed to people living longer...this phenomenon masks the declining fertility rate for a short time, but corrects over a generation or two....I believe the current world fertility rate is expressed at 2.4, and this is believed to actually be 2.1 at this time....2.1 is claimed as the break-even point of population stability....In any case the massive overpopulation boom touted by doomsday profits is not likely to occur anytime soon, and in fact the opposite is more likely to occur....another scientific prediction laid to rest....RIP

Your other source claims "Basically, countries with birth rates above 1.6 or 1.7 children per woman experienced fertility declines." Thus they are projecting global fertility rates into the future but it does not state what is today's global fertility rate so one can conclude if the population is now increasing or declining. The car is slowing down but it is still going forward. It looks like the car will stop sooner than most expected but that has yet to happen.

{Also, paraphrasing with multiple sentence fragments strung together looks to me like an acknowledgment you are trying to mislead.}

Found this...

https://www.worldometers.info/

Somehow, I doubt that anyone knows anywhere close to this precision.

Like the museum worker who said the dinosaur fossils were 300,000,007 years old because he was told they were 300 million years old when he first came to work there 7 years ago.

It's 2019/20, though. The graph goes to 2015.

Lots of angles shown here
https://population.un.org/wpp/Graphs/DemographicProfiles/Line/900

Some basic data here
https://www.worldometers.info/world-population/

Yeah, it seems to me that it is indeed the growth rate that is declining. And these two mavericks in the video are just using erroneous click-bait phrasing to get their products' airtime.

I'm guessing these two guys are graduates from The University Of The Freaking Obvious.

Or, as Tom Cruise rhetorically asked in Vanilla Sky: "What's the answer to 99 out of 100 questions?"

Money.

It may be declining faster if North Korea's Kim gives us our Christmas present.

That was a lot of talk for an explanation of 1.6 and 2.1

Cool. Makes sense

(They) can predict anything that suits them, especially since (they) won't be around in by the year 2200 to have to personally face the facts of their inaccurate prediction...

Please note that I am not forecasting that it is too high, or too low, but I am saying that it will mostly likely be inaccurate... (ie: tooooooo many variables to be very sure)

(Ask (me) again on New Year's Day in 2200...)

I have a problem understanding why an average of 2.1 children per woman is considered the value for a sustained population, when our life expectancy is around triple the generational period. I have to confess that I have NOT done any rigorous math, but if the average woman has an average of 2.1 children at an average age of something like 25 years, then that woman has a good chance of living until her grandchildren begin having children of their own.

Since the woman and her children and her grandchildren and a few great-grandchildren are mostly alive toward the end of her life, that certainly seems to me to be more people at the end of the period.

I'm aware that disease, accidents, etc., reduce the growth rate, but by how much?

The only thing that matters is how many kids they have had at the time of their death...then the same thing with the next generation, and the next, and the next and so on...If each woman has 2 children, one to replace herself and one to replace her husband, then they are at break even...add .1 for premature deaths...and the population is stabilized....below that and the population declines...it doesn't matter how many generations are presently living at the same time, as long as that number remains the same...as people live longer this gives the appearance that fertility rates are increasing, but it's only temporary because there is a limit to how long people can live...Currently life expectancy is declining in the US, this would add to population decline, but has nothing to do with fertility rates...

https://www.statista.com/statistics/274513/life-expectancy-in-north-america/

In a way you are correct: if you take a given population and snap to the "maintenance rate of 2.1" then the population does continue to increase (rapidly) for a long time, but ultimately the population stabilises. This effect tends to mask the long term result.

If you assume females make up 50% of the population, the replacement rate would be 2.0. Actually the male/female ratio is about 1.05, making the replacement rate 2.1.

https://en.wikipedia.org/wiki/Human_sex_ratio

Correction:

If you assume females make up 50% of the population, the replacement rate would be exactly 2.0. Actually the male/female ratio is about 1.05.

If M = 1.05 F, then M + F = 2.05 F, so it would seem that the average female needs to give birth to 2.05 children for a stable population, absent short term effects such as a change in longevity.

https://en.wikipedia.org/wiki/Human_sex_ratio

However, if you count the number of females at child-bearing age instead of at birth, female mortality before child-bearing age could make the factor 2.1.

https://www.quora.com/Why-is-the-replacement-fertility-rate-in-developed-countries-2-1-and-not-2-0

(Edit of previous post timed out even though the message indicated time left!)

Giving birth to more children does not guarantee more male than female offspring...unless I'm missing something...also women tend to live longer than men....

https://ourworldindata.org/why-do-women-live-longer-than-men

Giving birth to more children does not guarantee more male than female offspring...unless I'm missing something...

The ratio of male to female births is a statistical fact, 1.05 males to every female birth.

https://en.wikipedia.org/wiki/Human_sex_ratio

If M is the number of males born and F the number of females, then

M = 1.05 F.

For a stable population, the total number born, M + F = 2.05 F, is the number of people that will have to be replaced by the F females born. If some of these females die before reaching child-bearing age, the survivors will have to pick up the slack, resulting in a higher replacement rate (2.1).

...also women tend to live longer than men....

It's more important for females to reach childbearing age, so possibly evolution has spent more effort on females' survival...just my private theory.

The sex ratio at birth and the difference in male/female may be related. Fisher's Principle states that evolution will drive the sex ratio to 1:1. If male mortality is higher than female, then more males than females would be born to make the ratio close to 1:1 at childbearing age.

https://en.wikipedia.org/wiki/Fisher%27s_principle

..."The sex ratio for the entire world population is 101 males to 100 females (2018 est.).^[7] Depending upon which definition is used, between 0.1% and 1.7% of live births are intersex.^[8][9] "...

Seems like some blurring of lines is open to interpretation...? Not to mention the men trapped in women's bodies, and vice versa....

https://williamsinstitute.law.ucla.edu/research/census-lgbt-demographics-studies/how-many-people-are-lesbian-gay-bisexual-and-transgender/

https://en.wikipedia.org/wiki/Human_sex_ratio

I don't think a definitive answer is available...

While the birth rate is declining both adult longevity and the survival rate for young children is increasing due to advances in healthcare, crop yields, nutrition and wealth. To look at birth rate only does not give an accurate picture of population growth.

I don't believe population is shrinking at present but I think that in the near future (next 100 years) a combination of sea level rise and extreme weather conditions in currently fertile areas will strain our ability to feed even a stable population. As one region ceases to produce food currently infertile areas will be developed. Should we be starting to develop those areas now? Will we be able to keep up with the losses or do we let people starve to redress the balance? Charles Darwin's "The Origin of the Species" tells us that if food supply does not meet the needs or the location of a population then that population moves or shrinks. Do we need to discuss the dismantling of national borders in preparation for mass migrations of population?

Nonsense we have an overabundance of food....why do you think everybody is overweight?

We could easily support twice as many people...

That's true in the US, and is becoming true in some other countries as fast food chains move to those countries, but it is really obvious when traveling to other countries, that their populations are significantly less obese than ours.

There are over 100 countries where the obesity rate exceeds 20%...

https://obesity.procon.org/global-obesity-levels/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4212551/

Wow! It's worse than I thought! Most of the countries I've traveled to are not on that list, and for the two that are, the trips were quite a few years ago.

It’s interesting, that large conglomerate have chemists in their labs that do nothing than to put it lightly,... make their product more ‘appealing’

but the actual term is to make their food stuff products addicting...

ADMIN note: content redacted

This post has been deleted to remove political commentary.

https://www.ted.com/talks/hans_rosling_global_population_growth_box_by_box?utm_campaign=tedspread&utm_medium=referral&utm_source=tedcomshare

Great Ted Talk in the subject.

Norm

The GROWTH RATE is declining. The population GROWTH is still increasing. Certain European and Japanese population reproduction rates are low enough that the the population is not self sustaining without immigration. We haven't hit carrying capacity quite yet for the planet, but have in localized areas.

Well the population is increasing mainly because of people living longer....With fertility rates decreasing and longevity increasing, this tends to skew the perception, but eventually longevity hits a wall, then you are left with only fertility rates...

I am surprised that there has been so little discussion of infant mortality herein.

The poorer the country, the less Welfare, health insurance, and most importantly, Social Security. In such countries, large families are necessary to work the (farms), and support the parents, until those parents (expire...) Two centuries ago, infant mortality was relatively high, even in the U. S. ...

Hence, more babies were needed to be born, in the hopes that enough would survive well enough into adulthood to take over caring for their parents when those parents can no longer do much useful work... More babies then, more caregivers availabe later...

However, modern medicine, better education, and more healthly hygiene, has helped more babies survive longer, thereby lessening the traditional need for more babies, therefore, lower birth rates allow for better lifestyles, relatively speaking.

More (modern-ness) promotes better infant survival, fewer babies needed, hence, lower birthrates more affordably chosen...

Then there is also the complication of death in childbirth. It almost makes one think the human population should never have grown to what it is now, yet here we are.