World population is growing 20 million people every 3 months

[UAEguy]

Found this interesting on Quora from Narayanan Unni, Worked in Demographic analysis of Indian census data for more than a decade
Written Jul 5, 2016
Regarding the accuracy of the population census, one has to understand that such a gigantic task involving more than 2 million enumerators (more than the population of some countries) collecting data is likely to have some errors. They key to success is in keeping the errors to manageable levels. In that Indian censuses over the years have been doing a good job. Census organization itself conducts an evaluation survey after the census and it had estimated that about 2% of the population gets omitted in census. Compare this with that of South Africa, a country that has spent much more per-capita on census, at 14.6%. (http://www.statssa.gov.za/census...)

[Cottontop]

Originally Posted by pete33458

I think there's no reason to project less than exponential human population growth in the absence of limitations in food or shelter or the appearance of an apex predator.

Pete

Here are a couple of reasons: fewer people involved in agriculture (where children are an economic benefit because they can be put to work), and contraception.

Japan's population is declining (no apex predator involved). So is Russia's. European fertility rates are way below replacement; in a few years most European countries will experience declining populations without immigration. China's fertility rate is below replacement; China's population will peak in about 2030 and begin declining. India's fertility rate has dropped dramatically, although its population will increase for quite a while. The US is about breakeven without immigration.

The correlation between increasing wealth and decreasing fertility rates is about as strong as correlation gets. You want fewer people? Support economic growth.

[daletournier]

Originally Posted by AiniA

If they are guessing why are you prepared to accept the current population of the earth? Perhaps the world has 6 billion or 9 billion now? I think the UN and other estimates are probably pretty good, likely within 5% of the real numbers, perhaps more like 1%. Note that in the graph I provided once you agree on a current population the projections are just calculations based on different TFRs.

After I retired I volunteered in the highlands of Lesotho for several months. While I was there they were getting ready to conduct their first census. It is not a rich, or even working class country but they thought it important enough to have a count and seemed to be quite serious about it. They were giving teachers training about how to do the count. I would think it worked out pretty well since everyone was taking the process very seriously. I am also reminded of an episode of the West Wing where there was considerable discussion about the merits of a census (count) vs a sampling to determine population.

5% or 1% ,now your guessing, you wouldn't have a clue and neither do I.
When I showed that graph it was to point out the UN suggests it could go one of the three ways. No one can know the future, accept for us google experts of course :-)
In regards to my accepting the current population, who said I do? I don't know what it is, 1% out, 10% , I don't know. The greatest scientific minds of the world once believed the earth was flat and medical practitioners bled people to supposedly cure all sorts of things, science and the UN aren't the be all and end all, they are fallible.
What I do know is that we are animals and its built into us to breed, this is what we do. Most people have kids and then the kids have kids, that's just the way it is, unless external events force a change ie. lack of food etc this will continue and the population will grow.
Something Dh said earlier regarding how much can the world can sustain? Good question! once again I have no idea? I do know that infinite growth in a finite world is non sustainable at some point, where that point?once again I have know idea.
The stadium eg of expotential growth I posted way back was purely to show how quickly it happened once that point is reached.


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[UAEguy]

Originally Posted by AiniA

I have been studying and teaching this stuff since the 1970s and the rate at which demographic transition is occurring has typically been underestimated, i.e. population projections made in 1980 or 1990 turned out to be much higher than what actually transpired.

https://ourworldindata.org/world-population-growth/

The problem remains...nobody seems to question the accuracy of the data and veracity of the conclusions relative to the statistical margins. If your data has a margin of error greater than your entire result, it is speculation. Most engineers deal with this every day. If this was presented at a DARPA conference, the first question asked would be "What is your data set margin of error and confidence level?" That answer better justify the significant figures in your graph.

Then, the following question would be how do you know?

[Cottontop]

Originally Posted by Cottontop

Here are a couple of reasons: fewer people involved in agriculture (where children are an economic benefit because they can be put to work), and contraception.

Japan's population is declining (no apex predator involved). So is Russia's. European fertility rates are way below replacement; in a few years most European countries will experience declining populations without immigration. China's fertility rate is below replacement; China's population will peak in about 2030 and begin declining. India's fertility rate has dropped dramatically, although its population will increase for quite a while. The US is about breakeven without immigration.

The correlation between increasing wealth and decreasing fertility rates is about as strong as correlation gets. You want fewer people? Support economic growth.

A couple more reasons: decreasing child mortality; it's no longer necessary to have 8 kids to ensure 2 survive. And why did you want them to survive? To take care of you in old age. But that's changing; becoming a societal responsibility rather than a family one.

Both Germany and Italy experienced population declines last year.

[Cottontop]

Originally Posted by Cottontop

A couple more reasons: decreasing child mortality; it's no longer necessary to have 8 kids to ensure 2 survive. And why did you want them to survive? To take care of you in old age. But that's changing; becoming a societal responsibility rather than a family one.

Both Germany and Italy experienced population declines last year.

In 1970, Brazil's fertility rate was 5.4. Last year it was 1.8 (below replacement).

[Cottontop]

Originally Posted by Cottontop

In 1970, Brazil's fertility rate was 5.4. Last year it was 1.8 (below replacement).

Another big country: Indonesia. Fertility rate in 1970 - 5.6. Last year - 2.5. Still above replacement, but down by more than 50%.

The sky is not falling.

[hoppy]

A very interesting video

https://www.youtube.com/watch?v=FACK2knC08E

[AiniA]

Originally Posted by daletournier

[snip]

What I do know is that we are animals and its built into us to breed, this is what we do. Most people have kids and then the kids have kids, that's just the way it is, unless external events force a change ie. lack of food etc this will continue and the population will grow.

[snip]

My last contribution to this thread since it is pointless trying to convince people whose minds are made up in spite of evidence to the contrary. Lets ignore the population 'experts', what the hell do they know. Consider your own family and those of people you know. Assuming you are an older adult, how many kids do you have? How many kids do they have? How many kids did your parents have? How many kids did your grandparents have? In my case, I had two kids. They, in total, have three - it would have been two but twins happened. My parents had four kids. My grandparents who were farmers averaged eight. So in four generations, in Canada, it went from 8 to 4 to 2 to 1.5. That is demographic transition and has happened and is happening everywhere in the world except for a tiny handful of North African countries that do not have large enough populations to matter.

People are not animals who breed within the limits of their environments, except perhaps at Stage 1 of demographic transition - and there are no countries in the world still at that stage. It is silly to suggest otherwise. Unfortunately, and to our harm, we live in a time of alternative facts and rampant anti-intellectualism. To me, facts are facts and ignorance is ignorance.

[K_V_B]

Originally Posted by a64pilot

There are differing types of hybrid, parallel, series etc.
A train is a series hybrid.

With often several hundreds of km. between the generator and the motor part of the hybrid :-)

[K_V_B]

Originally Posted by daletournier

What I do know is that we are animals and its built into us to breed, this is what we do.

If that "is what we do", why am I, and many others, not observing us doing it?
If grew up with four siblings. A large family even at that time. Of the five of us only three have kids.
Total Fertility Rate is below replacement level in most European countries. If you go to a zoo, or an amusement park, you will see groups of four adults taking one child out...

So it appears that breeding is no longer what we do...

[a64pilot]

Originally Posted by K_V_B

With often several hundreds of km. between the generator and the motor part of the hybrid :-)

I get the humor, but that's not a hybrid unless the train has another motor on board, and I don't think the ones that get their power from overhead lines or third rails do?

[boatman61]

Originally Posted by AiniA

My last contribution to this thread since it is pointless trying to convince people whose minds are made up in spite of evidence to the contrary. Lets ignore the population 'experts', what the hell do they know. Consider your own family and those of people you know. Assuming you are an older adult, how many kids do you have? How many kids do they have? How many kids did your parents have? How many kids did your grandparents have? In my case, I had two kids. They, in total, have three - it would have been two but twins happened. My parents had four kids. My grandparents who were farmers averaged eight. So in four generations, in Canada, it went from 8 to 4 to 2 to 1.5. That is demographic transition and has happened and is happening everywhere in the world except for a tiny handful of North African countries that do not have large enough populations to matter.

People are not animals who breed within the limits of their environments, except perhaps at Stage 1 of demographic transition - and there are no countries in the world still at that stage. It is silly to suggest otherwise. Unfortunately, and to our harm, we live in a time of alternative facts and rampant anti-intellectualism. To me, facts are facts and ignorance is ignorance.

I have one then divorced.. son has 3.
My sister has 5.. not divorced..
Father had 3 brothers 4 sisters.. mother had one brother.
Oh..!!! and my ex wife went on to have 3 more..

[K_V_B]

Originally Posted by hoppy

A very interesting video

Hans Rosling sadly passed away two months ago. You have to give it to the guy: Suffering from bad health all his life he nevertheless relentlessly campaigned for optimism where the state of the world is concerned.

Hist website: Gapminder: Unveiling the beauty of statistics for a fact based world view. is a must for anyone interested in what really is going on with the health and well being of the world.

[K_V_B]

Originally Posted by a64pilot

I get the humor, but that's not a hybrid unless the train has another motor on board, and I don't think the ones that get their power from overhead lines or third rails do?

Well, the original remark was that "trains are serial hybrids". In truth the majority of trains aren't...