World population is growing 20 million people every 3 months

[Dockhead]

Originally Posted by boatman61

So are human beings.. last WW cost 60 million.. the next one may cost 6 billion or more.. and contaminate huge expanses of land for hundreds of years.. seem to remember an old Navajo legend where 'The People' had to live under ground for over five hundred years while the fires of hell reigned above.
Love mankinds certainty about their abilities to 'Control and Predict'..

Indeed. There are lots of downside scenarios to the demographic predictions. We are looking at the "worst case" -- "worst" meaning "the most people", even though too few people may soon be a bigger threat.

A horrible pandemic or a really big war could really chop those numbers down -- you are definitely right. God forbid.

As to contamination, though -- I doubt it. The biggest nuclear weapons are fusion devices which don't leave much contamination. In a big nuclear war a lot of cities could be destroyed utterly and become uninhabitable for some time, but there will be plenty of other land to build new ones -- if enough people survive.

"If enough people survive" refers to the possibility that a big enough nuclear war could cause extinction of the human race through other mechanisms ("nuclear winter" being the main one -- maybe global warming before then will save us ). No one knows for sure whether that could or would happen, but it doesn't seem to be out of the realm of possibility. See: https://en.wikipedia.org/wiki/Nuclear_holocaust

[pete33458]

Originally Posted by Dockhead

A horrible pandemic or a really big war could really chop those numbers down -- you are definitely right. God forbid.

I'm not sure about the God forbid part (it might be the best thing that ever happens), but from a scientific standpoint (mine), a horrible pandemic is inevitable. Everything evolves (except humans; one might argue, and some have, that we are devolving with respect to fitness for survival), and evolution is driven by natural selection. The selection imposed by antibiotics (not just in humans, but much more extensively in livestock), together with the incredible growth and mutation rate of microbial organisms, WILL eventually lead to a pandemic event. Everyone is aware of the little peeks that we are already getting into this future reality, the most well known is MRSA but there are many others. It's just a matter of time. I'm not a doomsayer, I'm a pragmatist. I have no self-serving interest in seeing this happen, or in pretending that it won't.

Regarding population growth, everyone likes to lament it as if it's someone else's doing, but few people seem to be willing to do what it takes to stop it. I made that commitment decades ago (before it was too late...), and each passing day reaffirms my decision.

It is interesting to note that for most species (i.e., every species other than Homo sapiens), population growth is limited by habitat, food, and predators. We can expand our habitat to any environment, we can destroy anything that stands in our way (animal, vegetable, or mineral) of making more "food" (technically, making more money), and we have no apex predators. It is truly a brave new world.

There's my happy thought(s) for the day. Discuss among yourselves!

Pete

[valhalla360]

Originally Posted by pete33458

I'm not sure about the God forbid part (it might be the best thing that ever happens), but from a scientific standpoint (mine), a horrible pandemic is inevitable. Everything evolves (except humans; one might argue, and some have, that we are devolving with respect to fitness for survival), and evolution is driven by natural selection. The selection imposed by antibiotics (not just in humans, but much more extensively in livestock), together with the incredible growth and mutation rate of microbial organisms, WILL eventually lead to a pandemic event. Everyone is aware of the little peeks that we are already getting into this future reality, the most well known is MRSA but there are many others. It's just a matter of time. I'm not a doomsayer, I'm a pragmatist. I have no self-serving interest in seeing this happen, or in pretending that it won't.

Regarding population growth, everyone likes to lament it as if it's someone else's doing, but few people seem to be willing to do what it takes to stop it. I made that commitment decades ago (before it was too late...), and each passing day reaffirms my decision.

It is interesting to note that for most species (i.e., every species other than Homo sapiens), population growth is limited by habitat, food, and predators. We can expand our habitat to any environment, we can destroy anything that stands in our way (animal, vegetable, or mineral) of making more "food" (technically, making more money), and we have no apex predators. It is truly a brave new world.

There's my happy thought(s) for the day. Discuss among yourselves!

Pete

It's a common flaw that people think of evolution as making the next generation faster, stronger, smarter, etc...if it doesn't make you more likely to reproduce, evolution doesn't care. Slugs have been around for a very long time but they aren't going to win a game of chess or a foot race.

As far as population explosions and then collapses, it's actually fairly common situation particularly when a key evolutionary step is made that makes a species have a huge competitive advantage...suddenly the population constraints are lifted until the system comes into balance.

The difference is if anything humans are consciously adapting and bringing the population growth under control outside of evolutionary processes.

[pete33458]

Originally Posted by valhalla360

It's a common flaw that people think of evolution as making the next generation faster, stronger, smarter, etc...if it doesn't make you more likely to reproduce, evolution doesn't care. Slugs have been around for a very long time but they aren't going to win a game of chess or a foot race.

As far as population explosions and then collapses, it's actually fairly common situation particularly when a key evolutionary step is made that makes a species have a huge competitive advantage...suddenly the population constraints are lifted until the system comes into balance.

The difference is if anything humans are consciously adapting and bringing the population growth under control outside of evolutionary processes.

Hopefully the "people" you were referring to didn't include me, because I made no claims about what evolution is other than selection of the fittest. "Fittest," in the context of evolution, means best able to survive the prevailing conditions, and has nothing to do with fast, strong, or smart, unless those are the qualities that make you best able to survive the prevailing conditions.

[conachair]

Originally Posted by valhalla360

It's a common flaw that people think of evolution as making the next generation faster, stronger, smarter, etc....

ISTR Jared Diamond discussed this in Guns, Germs and Steel, hunter-gatherers need to be fit, clever, strong and fast to survive. In an agricultural society you can be slow and stupid, just don't die of infectious diseases to survive..

[UAEguy]

Originally Posted by pete33458

I'm not sure about the God forbid part (it might be the best thing that ever happens), but from a scientific standpoint (mine), a horrible pandemic is inevitable. Everything evolves (except humans; one might argue, and some have, that we are devolving with respect to fitness for survival), and evolution is driven by natural selection.

It is interesting to note that for most species (i.e., every species other than Homo sapiens), population growth is limited by habitat, food, and predators. We can expand our habitat to any environment, we can destroy anything that stands in our way (animal, vegetable, or mineral) of making more "food" (technically, making more money), and we have no apex predators. It is truly a brave new world.

There's my happy thought(s) for the day. Discuss among yourselves!

Pete

An interesting note Pete regarding devolving of the human race. While traveling the world, my wife and I noted the likelihood that populations like Indonesians, Cambodians and Vietnamese would best survive an apocalyptic event because 1st World populations would collapse if you simply pull the plug on electricity, ready made food and clean water.

The US would be worst hit in my opinion. Take away electricity for a week and people would start killing each other for canned food.

[pete33458]

Originally Posted by UAEguy

An interesting note Pete regarding devolving of the human race. While traveling the world, my wife and I noted the likelihood that populations like Indonesians, Cambodians and Vietnamese would best survive an apocalyptic event because 1st World populations would collapse if you simply pull the plug on electricity, ready made food and clean water.

The US would be worst hit in my opinion. Take away electricity for a week and people would start killing each other for canned food.

Couldn't agree more, although infectious diseases GENERALLY don't discriminate (AIDS, for instance, does). But I think the end result of any global calamity (disease or otherwise) would still be the breakdown of civilization, in which case those populations that are "less civilized" would probably have a better chance.

BTW, I am not in any way deriding what are referred to as "less civilized" populations, in fact, I think that their way of life is, in many ways (but not all), better than ours.

Pete

[UAEguy]

Originally Posted by Dockhead

Talk to any actual demographer if you still think that global population even can grow "exponentially". This is simply -- nonsense. As you can see in the graph Stu posted, global population growth rate has already fallen to half of the peak rate achieved around 1960 -- and basic factors identified in the Demographic Transition Model indicate that this continues until global population begins declining.

Attachment 144864

DH, I challenge you to graph actual published datasets for population over the past 50 years and then take into consideration the accuracy range of those data sets, and you will CLEARLY realize that the claimed decrease in population growth falls firmly within that range. Therefore I can just as easily present data and graphs with the opposite conclusion. At this time in history and with the data collection methods available, we can only conclude that population growth is at a minimum...not that it is increasing or decreasing.

PRODUCERS OF POPULATION forecasts rarely report about the expected accuracy of their forecast results. The fact is surprising, because accuracy is animportant aspect of the quality of the forecast. Other aspects, such as the information content (e.g., only total population, or also age groups? which regional level?) and the usefulness for policy purposes (e.g., does the projected trend imply immediate policy measures?), are relevant as well, but the degree to which the forecast may be expected to reflect real developments in the future is a key factor in assessing its quality.
Most forecast reports do not give the expected accuracy of the population
forecast, simply because the forecast producer does not know this
himself.

If you want more information on this, http://pages.stern.nyu.edu/~dbackus/...man_JDR_98.pdf

[newhaul]

Originally Posted by UAEguy

An interesting note Pete regarding devolving of the human race. While traveling the world, my wife and I noted the likelihood that populations like Indonesians, Cambodians and Vietnamese would best survive an apocalyptic event because 1st World populations would collapse if you simply pull the plug on electricity, ready made food and clean water.

The US would be worst hit in my opinion. Take away electricity for a week and people would start killing each other for canned food.

Only the canned food with a pull tab. Most couldnt open a can without electricity.
( have a p38 on my keychain)

[UAEguy]

if you still think that global population even can grow "exponentially". This is simply -- nonsense.

I believe I demonstrated that human population has gone through an exponential growth period when starting from 1600. So to state that it is "impossible and nonsense" is entirely incorrect.

Human's could just as easily invent new technologies that enable another period of exponential growth. Such as the ability to colonize Mars. I admit the likelihood is low, but not impossible.

I'm sure that if you told someone in 1645 that one day, 1 human would be able to produce enough food for 155 humans as we do now, they too would think that was "impossible and nonsense".

[UAEguy]

How Accurate Are Population Projections?

The accuracy of current population projections cannot be directly evaluated, but the success of previous global and country-level projections can be examined. Twelve times since the 1950s, the UN has projected the world population size for the year 2000. All but one of these projections has been off by less than 4 percent.

Understanding and Using Population Projections

My case and point,
Let's just assume the average error has been 3%, it is thus pure statistical speculation to make statements about growth rates that are within the margin of error for your underlying data.

[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. None of which are presently a global problem. The only real caveat are that some people in some (mainly western) civilizations are producing replacements only (2 children per 2 parents). So it's not strictly a geometric expansion, but it's still exponential growth overall.

The other BIG, BIG influence (I would argue one nearly as big as population growth) is longevity. Life expectancy has almost doubled in the past century. That means that each human contributes twice as many man-years of consumption as we did about 100 years ago. It's the same as doubling the population. The number of countries (and people) where lifespan is increasing is growing by the day (i.e., it used to be limited to wealthy countries, but is now expanding rapidly to all cultures).

Pete

[AiniA]

Originally Posted by UAEguy

Almost QED but not quite. My data set shows "almost" linear with slightly increasing slope. Again everything depends on your selected x(0) point and who's data you believe.

But again, I concede no exponential over the last 100 years if you don't include prior history. I think the same can be said for US debt somewhere along the way.

A good exercise nonetheless and I continue to question the assumptions that humans are going to go retrograde in the next 30 years. But, I wont be here to find out.

Here is a recent history and future projection for population growth rates. What happened before 1950 is of little significance except that it provides a basis for later growth. As we proceed what we have is a situation where there will be fewer women in their primary child-bearing years (say 18-35) as the population growth rate declines. Note that this graph has population growth petering out shortly after 2100. Many other studies suggest an earlier date for this. 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.



The website that this graph comes from is quite good and worth a read.

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

[AiniA]

Originally Posted by UAEguy

DH, I challenge you to graph actual published datasets for population over the past 50 years and then take into consideration the accuracy range of those data sets, and you will CLEARLY realize that the claimed decrease in population growth falls firmly within that range. Therefore I can just as easily present data and graphs with the opposite conclusion. At this time in history and with the data collection methods available, we can only conclude that population growth is at a minimum...not that it is increasing or decreasing.

PRODUCERS OF POPULATION forecasts rarely report about the expected accuracy of their forecast results. The fact is surprising, because accuracy is animportant aspect of the quality of the forecast. Other aspects, such as the information content (e.g., only total population, or also age groups? which regional level?) and the usefulness for policy purposes (e.g., does the projected trend imply immediate policy measures?), are relevant as well, but the degree to which the forecast may be expected to reflect real developments in the future is a key factor in assessing its quality.
Most forecast reports do not give the expected accuracy of the population
forecast, simply because the forecast producer does not know this
himself.

If you want more information on this, http://pages.stern.nyu.edu/~dbackus/...man_JDR_98.pdf

The UN's population projections come with varying predictions based on different fertility scenarios. You can take your pick about which one is most likely to happen. Over the past few decades the fertility rate decline has typically been underestimated.

[AiniA]

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. None of which are presently a global problem. The only real caveat are that some people in some (mainly western) civilizations are producing replacements only (2 children per 2 parents). So it's not strictly a geometric expansion, but it's still exponential growth overall.

The other BIG, BIG influence (I would argue one nearly as big as population growth) is longevity. Life expectancy has almost doubled in the past century. That means that each human contributes twice as many man-years of consumption as we did about 100 years ago. It's the same as doubling the population. The number of countries (and people) where lifespan is increasing is growing by the day (i.e., it used to be limited to wealthy countries, but is now expanding rapidly to all cultures).

Pete

See the two previous posts. Population growth is not exponential, far from it. Below replacement fertility rates already exist is countries as diverse as China, Nicaragua, Iran, and Viet Nam (see link below). Before you can posit an idea like this you need to have data to support it. Most countries with below replacement rate fertility achieved this status in the past 20 to 30 years. It takes time for the impact of this to work through the system. There can be a lot of young women having children because fertility rates a generation ago were much higher. Now they are much lower so in the next generation there will be a lot fewer girls to have babies - that is when you the population drop off.

Population projections take into account increasing life expectancies. In fact, at the top of the LE table rates of increase are very low. In some cases, life expectancy is declining - such as parts of the US and among men in Russia.