# How do we know there are 7.6 Billion People on Earth? **URL:** \ **Category:** Factual Questions\ **Created:** [March 21, 2018, 2:12am UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937 "2018-03-21T02:12:48Z")\ **Posts on this page:** 14\ **Page:** 2
**Author:** ![k9bfriender](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k9bfriender/32/3283_2.png) [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)\ **Post date:** [March 22, 2018, 8:10pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/21 "2018-03-22T20:10:44Z")
> [@Stranger\_On\_A\_Train](#): > > And more importantly, _provide options for both birth control and universal basic health services so that people don’t feel compelled to have more children than they can support_. This is moral problem for some people who hold onto archaic views about family planning. > > Stranger You also need to have a comprehensive safety net. Having children used to be your social security, and still is in many parts of the world. It’s not just having more children than you can support, it’s not having to have so many children to support you. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [March 22, 2018, 9:38pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/22 "2018-03-22T21:38:46Z")
> [@sbunny8](#): > > There’s a light at the end of the tunnel. > > The good news is that the number of children born each year is been fairly flat for the last few decades, around 130-140 million babies per year and expected to decrease slightly in the coming decades… This is a political statement, actually. The negative growth rate in Europe relative to that of the waves of immigration is considered bad news by many; Chinese population skewing–let alone the political mandating of “good news” of forcing low birth–is not good news for many… [exit GQ for continuation]. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [March 22, 2018, 10:03pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/23 "2018-03-22T22:03:11Z")
Easy. Pick a random square mile on the Earth’s surface, count the people in it, and multiply by 197 million. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [March 22, 2018, 10:19pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/24 "2018-03-22T22:19:04Z")
> [@Dr.Strangelove](#): > > Easy. Pick a random square mile on the Earth’s surface, count the people in it, and multiply by 197 million. There are 58 million square miles of terrestrial area on Earth. But “picking a random square mile” is not a stastically valid representation of population density giving how wildly population density varies from about \>2000 people per square meter for the most densely populated urban areas to virtually zero people per square kilometer in Greenland or Antarctica (or any number of inland deserts and mountains), nor does it tell you anything about the demographics about how populations may tend to grow or shrink based on birth rates and socioeconomic trends. Stranger ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [March 22, 2018, 10:32pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/25 "2018-03-22T22:32:02Z")
> [@Bryan\_Ekers](#): > > Is this about overpopulation or opiate abuse? You don’t get high from opium; it is a depressant. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [March 22, 2018, 10:32pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/26 "2018-03-22T22:32:55Z")
I agree that my method has some minor statistical flaws. For instance, my random square mile happened to be a patch of ocean with no people on it. Since I know Earth contains at least one person and I calculated zero, there is at least some small error in the calculation. More seriously, you could use a variant of the method if you could guarantee proportional sampling of small urban areas. Ten thousand 100 m[sup]2[/sup] random squares would likely provide a decent estimate while still only using 1 km[sup]2[/sup]. Though it would still be fairly noisy since there are some very small and very dense places that could evade sampling. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [March 22, 2018, 10:38pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/27 "2018-03-22T22:38:39Z")
> [@Jasmine](#): > > I’ve always considered world population figures to be an intelligent estimate… Obviously, any precise figure is questionable. There are 4-5 babies born on Earth every second (and only 1-2 people die per second), so any count will be constantly changing. An intelligent estimate is the best we can hope for. And it’s good enough to work with. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [March 22, 2018, 11:00pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/28 "2018-03-22T23:00:53Z")
As the cost of living (and hence the cost of raising children) rises in relation to earnings, the birth rate falls. When that happens the average age of a population increases, eventually to the point where it affects the economic viability of the country. > [@](#): > > Despite the increase [in 2016 after the one baby policy was scrapped], China’s fertility rate remains below replacement level — at which a population naturally replenishes itself from one generation to the next — where it has languished for years, according to the National Population Development Plan 2016 - 2030, issued by China’s State Council, the country’s cabinet. > [https://www.cnbc.com/2017/01/28/china-population-crisis-new-two-child-policy-fails-to-yield-major-gains.html](https://www.cnbc.com/2017/01/28/china-population-crisis-new-two-child-policy-fails-to-yield-major-gains.html) > [@](#): > > Italy’s population growth has been stagnating. In 2006, the population numbered 58.8 million, which has only grown by 3.9% since 1986. This compares with growth of 12.4% for Western Europe. Italy’s aging population is due to longer life expectancy and low birth rates, which will be magnified by the increased rate of deaths going forward, given the aging population: > > Concurrent with the expected reduction in population, those aged over 65 are growing in numbers. They numbered 11.6 million in 2006 compared to 8.2 million of those aged 0-14 years. The former age group has grown by 10.4% between 2001 and 2006 whilst the latter group has grown by 1.9%; > There are 12.7 million pensioners in Italy, accounting for 21.6% of the population in 2006 compared with 18.0% for the Western European average. > [https://blog.euromonitor.com/2007/09/italian-ageing-and-declining-population-will-affect-consumption.html](https://blog.euromonitor.com/2007/09/italian-ageing-and-declining-population-will-affect-consumption.html) > [@](#): > > The United States population grew by 0.7 percent in the last year, its smallest annual expansion in 80 years, the Census Bureau said this week. > > The nation added about 2.2 million people from July 2015 to July 2016, bringing the total population to just over 323 million. In relative terms, that was the slowest rate of annual growth since 1937, though census methods have changed over that time. > [https://www.nytimes.com/2016/12/22/us/usa-population-growth.html](https://www.nytimes.com/2016/12/22/us/usa-population-growth.html) ---
**Author:** ![vivalostwages](https://avatars.discourse-cdn.com/v4/letter/v/d07c76/32.png) [@vivalostwages](https://boards.straightdope.com/u/vivalostwages)\ **Post date:** [March 23, 2018, 3:21am UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/29 "2018-03-23T03:21:36Z")
> [@Jasmine](#): > > I’ve always considered world population figures to be an intelligent estimate, not the precise Gospel Truth. What’s important to me is that the world population is too high and it is getting higher daily. Agreed. But many will say that your comments are against G-d. [http://thefamilyleader.com/debunking-the-myth-of-overpopulation/](http://thefamilyleader.com/debunking-the-myth-of-overpopulation/) My older niece would agree. She has posted that there is no overpopulation and there’s plenty of room and plenty of food for everyone. :dubious: ---
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [March 23, 2018, 12:47pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/30 "2018-03-23T12:47:38Z")
> [@Stranger\_On\_A\_Train](#): > > Will you include an image of the Winter Soldier peeking around from behind Mark Zuckerberg? Because that would be awesome. > > Stranger Ha! Will do. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [March 23, 2018, 1:34pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/31 "2018-03-23T13:34:21Z")
> [@JKellyMap](#): > > Ha! Will do. And a clip of Nick Fury. [“…but if you want to stay ahead of me, Mr. Secretary, _you need to keep both eyes open_.”](https://m.youtube.com/watch?v=Xt74J40ANIQ&t=1m24s) Stranger ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [March 23, 2018, 3:14pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/32 "2018-03-23T15:14:49Z")
> [@Mrdeals](#): > > Is there a group that audits these numbers? What, did you miss the day last month when we all counted off in order? So the actual world population is 7,600,000,001. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [March 23, 2018, 4:53pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/33 "2018-03-23T16:53:28Z")
> [@zimaane](#): > > A concern in many developing countries is that the total for a census will be inflated because individual regions will try to inflate the numbers from their region, to attract more resources from the central government. If I recall, Giscard D’Estang once asked Mao how many people there were in China, and Mao replied- “we don’t know for sure, provincial officials overstate their population to get a bigger rice quota.” However, the short answer is - divide and conquer. For example - Is China hiding a hundred million too many - or too few? If so, where? take an individual population, one province, and you can’t hide 100M in 300M without some serious discrepancies. As things become more progressive, for example, students register for school - so the government can check school enrollment. they can check jobs and health registrations. Similarly for the USA, or any other country. Did 5M illegal immigrants vote in the last election? If so, where? Go through areas with many immigrants, and either one polling station had 1M extra voters (explains the lineups) or you should be able to check any location and find say, 10% extra voters who should not be there. (Conclusion, an aside, there simply isn’t the facts to support this). Same when doing a census - If there’s an extra million in Chicago or NYC or Frisco that aren’t being counted - where the heck do they live? did the census indicate a high number of empty apartments where these people are hiding? No? They can’t all live under overpasses. So this is the effect - you can check a particular count and get a pretty good idea if it’s accurate. Like the bus analogy, you can then spot check the result to see if there’s a detectable discrepancy, and how big it could be. Most first world numbers are probably pretty accurate. Every country in the world tries to count its population; most have a pretty good idea how many people live in the various areas of their country. The assumption is that there is not a systematic error where everyone is over- or under-counting. (Although the earlier link suggests there may be political reasons for some to.) But short answer is - it’s a guesstimate; probably not off by more than 5% or so. (The article suggests China is overstating population by 90M - that’s the difference between 7.60M and 7.51M; and that’s a possible error counting a fifth the population of the world. ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [March 23, 2018, 8:26pm UTC](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937/34 "2018-03-23T20:26:13Z")
> [@Jasmine](#): > > I’ve always considered world population figures to be an intelligent estimate, not the precise Gospel Truth. What’s important to me is that the world population is too high and it is getting higher daily. The rate of increase has been slowing since around 1960. Of course, it is still increasing, but apocalypse on that score no longer seems to be inevitable. > [@sbunny8](#): > > There’s a light at the end of the tunnel. (snip) > > The bad news is that the plateau is likely to be around 11 billion and many experts say Earth’s long-term human capacity is below 2 billion. But the good news is that we could get back down to 2 billion in less than a century without increasing the number of deaths per year. All it would take is decreasing the number of births to about one baby per woman. During the 20th century, the average number of babies per woman dropped from 5 to 1.6, mostly by convincing women that having lots of babies was not necessary for the family to prosper. If we build on that success and get the rate down to 1.0 babies per woman, the world population can drop to 2 billion in less than 100 years. First, I would be interested to know on what data or theories those “many experts” base their estimate of the long term capacity of the earth. Technological changes make a difference here. Second, the policy of 1 baby per woman (or couple) has not worked particularly well for China, and a birth rate that low creates ongoing problems which, if they are widespread instead of localized, would lead to premature death of the elderly. Is that how you want to reduce the population? I mean, once things are stabilized at 2 billion I suppose things might work out reasonably well when birth rate and death rate are about the same, but don’t be misled about the cost of the solution you are proposing. [Previous page](https://boards.straightdope.com/t/how-do-we-know-there-are-7-6-billion-people-on-earth/810937.md?page=1)