# Looking for scientifically sound arguments that predict a much slower world population growth by 2050 than the often cited estimate of 9 billion **URL:** \ **Category:** In My Humble Opinion\ **Created:** [April 20, 2022, 10:18am UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108 "2022-04-20T10:18:01Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Octagon](https://avatars.discourse-cdn.com/v4/letter/o/2acd7d/32.png) [@Octagon](https://boards.straightdope.com/u/Octagon)\ **Post date:** [April 20, 2022, 10:18am UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/1 "2022-04-20T10:18:01Z")
I’m looking for scientifically sound arguments that predict a much slower world population growth than the often cited estimate of 9 billion by 2050. I have read and heard over the years that the 2050 projection of 9 billion is overblown and that many countries will experience a rapid population decline. How sound are those arguments today and who is making them? I have looked for such scholarly articles recently but haven’t found them yet. ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [April 20, 2022, 11:45am UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/2 "2022-04-20T11:45:08Z")
The following statement: The one thing unfortunately about population projections is they will always turn out to be wrong. is made in this website: [https://www.nature.com/articles/d41586-021-02522-6](https://www.nature.com/articles/d41586-021-02522-6) ---
**Author:** ![Octagon](https://avatars.discourse-cdn.com/v4/letter/o/2acd7d/32.png) [@Octagon](https://boards.straightdope.com/u/Octagon)\ **Post date:** [April 20, 2022, 11:55am UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/3 "2022-04-20T11:55:15Z")
Thanks Wendell\_Wagner. ---
**Author:** ![Schnitte](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/schnitte/32/9033_2.png) [@Schnitte](https://boards.straightdope.com/u/Schnitte)\ **Post date:** [April 22, 2022, 10:21am UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/4 "2022-04-22T10:21:43Z")
I don’t have a cite for a source making this claim, but it would most likely have to be based on an increase in the stanrad of living in countries that are currently developing. Empirically, there’s a negative correlation between wealth and birth rates: The poorer a society, the more children people have on average. If you assume that the currently high-birth rate countries (many of which are in Africa) enjoy economic growth and an increase in standard of living in the next decades, that may well drive down their population growth. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [April 22, 2022, 12:04pm UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/5 "2022-04-22T12:04:30Z")
IIRC the 9B in 2050 estimate is the low projection from the UN in ~2010, which shows world population peaking in ~2050. Their other estimates (medium, high) show continued growth after that. Looks like there’s a Wikipedia article on population growth that might give you some citations. The only recentish (2010) lower projection I see is Jørgen Randers: peak of 8.1B in 2040s. All the more recent ones look a bit higher. > **[Population growth](https://en.m.wikipedia.org/wiki/Population_growth)** > > Pages for logged out editors learn more > > Population growth is the increase in the number of people in a population or dispersed group. Actual global human population growth amounts to around 83 million annually, or 1.1% per year. The global population has grown from 1 billion in 1800 to 7.9 billion in 2020. The UN projected population to keep growing, and estimates have put the total population at 8.6 billion by mid-2030, 9.8 billion by mid-2050 and 11.2 billion by 2100. However, some ac... ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [April 23, 2022, 6:21am UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/6 "2022-04-23T06:21:43Z")
Here’s a YouTube video on population trends: [![](https://img.youtube.com/vi/ncZW73QMBt8/maxresdefault.jpg "Why the World Stopped Having Children") ](https://www.youtube.com/watch?v=ncZW73QMBt8) ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [April 23, 2022, 2:28pm UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/7 "2022-04-23T14:28:52Z")
Incidentally, one reason that the population growth isn’t slowing down as much as expected is that while the number of children per family is decreasing, the average lifespan is increasing: [![](https://img.youtube.com/vi/-jSHWGWmg3U/maxresdefault.jpg "The Aging Population of the World") ](https://www.youtube.com/watch?v=-jSHWGWmg3U) ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [April 23, 2022, 3:21pm UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/8 "2022-04-23T15:21:14Z")
Pretty much everywhere outside of Sub Saharan Africa will see their population stabilize and decline (when you exclude immigration) between now and 2050. But due to severe poverty, population will grow in Sub Saharan Africa. The number of kids a woman has is negatively correlated with how wealthy and educated people are. When per capita income hits around $5000, women stop having more than ~2 kids, but a lot of Africa hasn’t hit that level of wealth yet. You need a total fertility rate (TFR) of 2.1 to maintain population stability. Below that it will decline. Pretty much the entire world is at or below 2.1 outside of Africa. There could be a bit of growth in Asia, but it’ll level off by mid century and then go down. [![](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Total_Fertility_Rate_Map_by_Country.svg/1200px-Total_Fertility_Rate_Map_by_Country.svg.png) ](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Total_Fertility_Rate_Map_by_Country.svg/1200px-Total_Fertility_Rate_Map_by_Country.svg.png) Supposedly population in Africa will grow from 1 billion now to 4 billion by 2100. [![](https://assets.weforum.org/wp-content/uploads/2015/08/150810-world-population-UN-WB.png) ](https://assets.weforum.org/wp-content/uploads/2015/08/150810-world-population-UN-WB.png) I’m confused as to why Asia will see its population go up between now and 2050 since China is at below replacement levels and India is only breaking even. Those 2 countries alone make up almost 2/3 of Asias population. In fact if you take the 10 most populated nations in Asia that probably make up 80-90% of asias total population, only 1 has a TFR higher than replacement levels from what I can tell (Pakistan). The other 9 are either at or below replacement. So where are the extra asians coming from? ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [April 23, 2022, 4:01pm UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/9 "2022-04-23T16:01:43Z")
The sources I’ve found say that the population of Africa will only be three times as high in 2100 as now. In any case, it’s clear what we should do. The level of wealth in most of Africa and much of Asia must increase. As that increases, the growth of the population will go down and eventually stabilize. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [April 23, 2022, 4:57pm UTC](https://boards.straightdope.com/t/looking-for-scientifically-sound-arguments-that-predict-a-much-slower-world-population-growth-by-2050-than-the-often-cited-estimate-of-9-billion/963108/10 "2022-04-23T16:57:50Z")
> [@Wesley\_Clark](#): > > I’m confused as to why Asia will see its population go up between now and 2050 since China is at below replacement levels and India is only breaking even. Those 2 countries alone make up almost 2/3 of Asias population. In fact if you take the 10 most populated nations in Asia that probably make up 80-90% of asias total population, only 1 has a TFR higher than replacement levels from what I can tell (Pakistan). The other 9 are either at or below replacement. So where are the extra asians coming from? The aforementioned increasing life span and the age distribution of the population. If you look at [the population pyramids](https://www.populationpyramid.net/asia/2020/) (very slow site) of Europe vs. Asia (or the individual countries). You’ll see that Europe has proportionally many more individuals who’ll move from “old” to “dead”, and fewer that move from “kid” to “child bearing age”, than Asia has. So Asia’s population will keep growing for a while while the large middle aged population ages into “old” and the shrinking, but still large, population of kids move into child bearing.