The world's population should be at most 50 million.

[Alan V]

That you can find malthusian nuts on the internet who are experts in something is entirely unsurprising to me. It doesn't change the fact that the basis for the position is non factual.   

Actually the population expert I mentioned was interviewed in a David Attenborough DVD I watched with my wife. BBC and all that.

Sorry, but your position on population is non-factual.

"Aside from the limited availability of freshwater, there are indeed constraints on the amount of food that Earth can produce, just as Malthus argued more than 200 years ago. Even in the case of maximum efficiency, in which all the grains grown are dedicated to feeding humans (instead of livestock, which is an inefficient way to convert plant energy into food energy), there's still a limit to how far the available quantities can stretch. 'If everyone agreed to become vegetarian, leaving little or nothing for livestock, the present 1.4 billion hectares of arable land (3.5 billion acres) would support about 10 billion people,' [eminent Harvard University sociobiologist Edward] Wilson wrote. The 3.5 billion acres would produce approximately 2 billion tons of grains annually, he explained. That's enough to feed 10 billion vegetarians, but would only feed 2.5 billion U.S. omnivores, because so much vegetation is dedicated to livestock and poultry in the United States. So 10 billion people is the uppermost population limit where food is concerned. Because it's extremely unlikely that everyone will agree to stop eating meat, Wilson thinks the maximum carrying capacity of the Earth based on food resources will most likely fall short of 10 billion."

https://www.livescience.com/16493-people...pport.html

Now I can credit such limits might be stretched based on your proposals, but I think it's simply foolish to believe that population can be unlimited.

[The Grand Nudger]

Let me lay out the basic case for population optimism.  It doesn't get much play, lol.  

Human beings are the ultimate human resource.  No other thing is as valuable to us as another thinking, problem solving human being.  There are never enough thinking, problem solving human beings working on any given problem.  You could always add another.  Historically, we've used population growth as a tool to combat resource availability issues, because population growth drives increased productivity.  This is the basis of a boserupian theory (the counter to malthusian theories).  Or, to use more generic terms, population pessimism and population optimism.  

Writing before the agricultural revolution..Malthus asserted that productivity (and specifically the productivity of land) was fixed, due to ag tech itself being fixed..which it largely was, in his pre-industrial timeframe.  An implication of that assumption was that a theoretical carrying capacity of any given chunk of rock could be derived.  His predictions did not come to pass for the simple fact that both the agricultural and industrial revolutions followed.  In truth, it began then, as a very important development in deep moldboard plows occurred in his lifetime.  His calculations, thusly..were off by orders of magnitude.  

Writing after the agricultural and industrial revolutions, chiefly interested in the history of agricultural intensification...Boserup noticed that the pull relationship that Malthus contentions depended on were also inaccurate.  Rather than population outstripping resource production..the reverse was true.  As population increased, resource production (real and potential) outstripped potential consumption, even though local shortages could be and were still common.  In effect, acknowledging that the data supported malthus contention at least insomuch as some present moment and some specific region, but denying that historical trends lent any credence to global malthusian effects.  

The pessimistic contention was rendered doa on account of being a failed prediction based upon shortsighted metrics and an inaccurate representation of the relationship between population and productivity in developing economies and methodologies.  That said.....nothing ensures that an optimistic theory will be true tomorrow, either.  

The pessimistic contention exploded again in the late 60's with the aptly titled book "The Population Bomb".  Warning us of mass starvation in the 70's and 80's.  Essentially rewarming the malthusian catastrophe argument from 1798.  It was, like it's predecessor..wrong, and wrong for the same reasons.  Unlike it's predecessor, however, it was more alarmist in it's tone and it's predictions were so immediate (and so immediately wrong) that it isn't looked at..today, with quite the same kindness that Malthus own interpretation was.  Nevertheless, it was this, more than anything else, that cemented the dire threat of overpopulation in the minds of the environmental movement.  This was reenforced in 09 when the erlichs stated that though they turned out to be wholly wrong, they still considered their argument fundamentally right..and that it had brought more people to the table of environmental consciousness..which was the ultimate goal.  To quote one of the most alarming statements, erlich wrote (and it was widely accepted at the time that he wrote it) that he couldn't see how india would be able to feed another 200million people by 1980.  It has since tripled it's population, and halved the ratio of malnourished citizens.  Corruption, incompetence, and global instability are now pointed to rather than overpopulation as the cause of local food shortage.  The optimistic contention was justified yet again in that exchange with the development of dwarf wheat coinciding with an intensification of productivity due to "surplus" population.  While this has been referred to as masked unemployment...ad that criticism has merit..it nevertheless entirely undercut the notion that india had a set carrying capacity, or that anyone knew what that was then or now.

Now, one of the stronger criticisms of optimistic population theory is that it may not accurately model relationships in a developed country.  The notion, again, being a rehashed malthusian catastrophe.  Those who offer this believe that while..yes, population increase can drive intensification and thus productivity, at some point the land has been "maximally intensified".  Innovation continues to prove this false on a yearly basis, but lets assume it were true.  Boserup had comments on this, while generally accepting that since the focus of her theory was development and intensification there may not be a one for one exchange in some other situation.  She noted, again, a historical trend of emigration.  A quick summary of her thoughts on the matter would be that in response to a local shortage, the population would breed labor and a deeper talent pool...drawing on this they would intensify to the limits of -their- ability...and upon reaching those limits, surplus population could and would emigrate to comparitively underdeveloped areas..leaving the native remnants in a decreasing state of fertility.  This has also turned out to be true in the developing (and now developed) world since the 50's.  Some localities, such as japan, have progressed so far along this path that they are now seeing sub replacement fertility levels, and a shrinking gdp, even as their base capacity metrics (by reference to some specific methodology) continue to rise.  The solution, for them..it's contended..is increased immigration - and immigrants have to come from somewhere, ultimately all immigrants come from the womb, lol. 

With all of that in mind, the newest face of population pessimism revolves around climate change.  Again the same assumptions are made..which have turned out to be both predictively and factual untrue time and time again.  Now, you'd think that people would get tired of predicting the apocalypse by any name...but, obviously, we don't.  It's an ancient pastime.  These advocates point to localized food shortage as justification for their assumptions..but as we discussed above, the failure of those assumptions and the identification of the cause of those shortages has since become a known know..and it's not overall population.  We could assume, like malthus in 1798..that "climate appropriate tech" is essentially fixed, in order to derive a theoretical carrying capacity.  We could assume, like the erlichs in the 60's, that nothing can be done to avert crisis beyond depopulation.

The trouble, is that these contentions have been consistently wrong for two centuries. How long do we have to wait, and how many times must it be proven wrong... before we let go of a bad idea? Specific methodologies have capacity limits. We have no idea what the limits of the earth are, and our demographic trends strongly suggest that whatever those are, if they exist, our own habits will effect us long before we reach any conceptual wall. This is what is meant by the statement "earths carrying capacity is practically limitless". It's not to say that there isn't a number of people you could stuff in the earth to finally fill it up, nut to butt....with no room for another - it's the acknowledgement that we have no reason to believe that our population will ever outstrip it's ability to secure resources..in practice. We will self reduce. We will get sick. We will start wars. We will come up with some New Way™ to do x y or z. We will emigrate as productive realities constrain or empower us. Evemn though we find ourselves with so many more people today..we find ourselves in exactly the same predicament Malthus was in. He never would have believed that the uk could carry a fraction of it's pop..and the amusing thing is that we know that it's at least -possible- for it to carry many more than it does today. Will this take a reorganization of our technologies and priorities..yes..but we've done so for all of our history as human beings. Adapt or die.

(I can identify the silent malthusian assumptions in your data above, if you like, but I wonder if you might be able to identify them? Can you think of a reason why those statements might be wrong, today...or tomorrow? I think, for example, that your characterization of innovation being able to "stretch" the numbers is wildly understated. Historically, they certainly have been. Presently...I described a system to you with twice the primary productivity, an additional waste stream of edible protein completely absent from conventional production, no site specifications, and no parity of environmental impact - that is what intensification looks like. I note that, just as we've done in the past, we'll need to increase our population in order to achieve that intensification. We could do it through reproduction or through immigration. It's only an idea until we can secure enough human capital and labor. So, seeing as how the numbers above are based on a better utilization of current ag, I'd contend that we could safely double that number, at least..and that's just today - for the simple reason that if all currently used conventional land was used for this or it;s equivalents, instead, that would be the takeaway -and that;s ignoring the fact that the systrem I described doesn;t actually need to use that productive land..like I said, you can turn a parking lot into a farm nowadays. Tomorrow, we might be able to go even bigger. Any hard cap on our pop due to food and water is so distant and so difficult to pin down, that it makes it seem silly, to me, to give such focus to that instead of directly addressing those issues towards which pop reduction is a very dubious proposal. It's wrong..and it's the wrong message for the environmental movement to send, if we want it to succeed. We need to weed out those bits of antique cultishness so often repeated that they're taken for fact, blindsiding those advocates who are unaware of mutually exclusive and more well evidenced positions. Population pessimism is just pessimism. It's not scientific, and it's not a fact, and it's not a solution. It has it's roots and it's motivations in a political ideology - and I'm not saying that the ideology is all bad, or that they don't make valid points within it, mind..I'm just trying to give you a clearer picture of the field. )

[Fidel_Castronaut]

I won't be leaving that many.

Me neither. We have no interest in having children. My money is much better spent on me.

[CarveTheFive]

Let me lay out the basic case for population optimism.  It doesn't get much play, lol.  

Human beings are the ultimate human resource.  No other thing is as valuable to us as another thinking, problem solving human being.  There are never enough thinking, problem solving human beings working on any given problem.  You could always add another.  Historically, we've used population growth as a tool to combat resource availability issues, because population growth drives increased productivity.  This is the basis of a boserupian theory (the counter to malthusian theories).  Or, to use more generic terms, population pessimism and population optimism.  

Writing before the agricultural revolution..Malthus asserted that productivity (and specifically the productivity of land) was fixed, due to ag tech itself being fixed..which it largely was, in his pre-industrial timeframe.  An implication of that assumption was that a theoretical carrying capacity of any given chunk of rock could be derived.  His predictions did not come to pass for the simple fact that both the agricultural and industrial revolutions followed.  In truth, it began then, as a very important development in deep moldboard plows occurred in his lifetime.  His calculations, thusly..were off by orders of magnitude.  

Writing after the agricultural and industrial revolutions, chiefly interested in the history of agricultural intensification...Boserup noticed that the pull relationship that Malthus contentions depended on were also inaccurate.  Rather than population outstripping resource production..the reverse was true.  As population increased, resource production (real and potential) outstripped potential consumption, even though local shortages could be and were still common.  In effect, acknowledging that the data supported malthus contention at least insomuch as some present moment and some specific region, but denying that historical trends lent any credence to global malthusian effects.  

The pessimistic contention was rendered doa on account of being a failed prediction based upon shortsighted metrics and an inaccurate representation of the relationship between population and productivity in developing economies and methodologies.  That said.....nothing ensures that an optimistic theory will be true tomorrow, either.  

The pessimistic contention exploded again in the late 60's with the aptly titled book "The Population Bomb".  Warning us of mass starvation in the 70's and 80's.  Essentially rewarming the malthusian catastrophe argument from 1798.  It was, like it's predecessor..wrong, and wrong for the same reasons.  Unlike it's predecessor, however, it was more alarmist in it's tone and it's predictions were so immediate (and so immediately wrong) that it isn't looked at..today, with quite the same kindness that Malthus own interpretation was.  Nevertheless, it was this, more than anything else, that cemented the dire threat of overpopulation in the minds of the environmental movement.  This was reenforced in 09 when the erlichs stated that though they turned out to be wholly wrong, they still considered their argument fundamentally right..and that it had brought more people to the table of environmental consciousness..which was the ultimate goal.  To quote one of the most alarming statements, erlich wrote (and it was widely accepted at the time that he wrote it) that he couldn't see how india would be able to feed another 200million people by 1980.  It has since tripled it's population, and halved the ratio of malnourished citizens.  Corruption, incompetence, and global instability are now pointed to rather than overpopulation as the cause of local food shortage.  The optimistic contention was justified yet again in that exchange with the development of dwarf wheat coinciding with an intensification of productivity due to "surplus" population.  While this has been referred to as masked unemployment...ad that criticism has merit..it nevertheless entirely undercut the notion that india had a set carrying capacity, or that anyone knew what that was then or now.

Now, one of the stronger criticisms of optimistic population theory is that it may not accurately model relationships in a developed country.  The notion, again, being a rehashed malthusian catastrophe.  Those who offer this believe that while..yes, population increase can drive intensification and thus productivity, at some point the land has been "maximally intensified".  Innovation continues to prove this false on a yearly basis, but lets assume it were true.  Boserup had comments on this, while generally accepting that since the focus of her theory was development and intensification there may not be a one for one exchange in some other situation.  She noted, again, a historical trend of emigration.  A quick summary of her thoughts on the matter would be that in response to a local shortage, the population would breed labor and a deeper talent pool...drawing on this they would intensify to the limits of -their- ability...and upon reaching those limits, surplus population could and would emigrate to comparitively underdeveloped areas..leaving the native remnants in a decreasing state of fertility.  This has also turned out to be true in the developing (and now developed) world since the 50's.  Some localities, such as japan, have progressed so far along this path that they are now seeing sub replacement fertility levels, and a shrinking gdp, even as their base capacity metrics (by reference to some specific methodology) continue to rise.  The solution, for them..it's contended..is increased immigration - and immigrants have to come from somewhere, ultimately all immigrants come from the womb, lol. 

With all of that in mind, the newest face of population pessimism revolves around climate change.  Again the same assumptions are made..which have turned out to be both predictively and factual untrue time and time again.  Now, you'd think that people would get tired of predicting the apocalypse by any name...but, obviously, we don't.  It's an ancient pastime.  These advocates point to localized food shortage as justification for their assumptions..but as we discussed above, the failure of those assumptions and the identification of the cause of those shortages has since become a known know..and it's not overall population.  We could assume, like malthus in 1798..that "climate appropriate tech" is essentially fixed, in order to derive a theoretical carrying capacity.  We could assume, like the erlichs in the 60's, that nothing can be done to avert crisis beyond depopulation.

The trouble, is that these contentions have been consistently wrong for two centuries. How long do we have to wait, and how many times must it be proven wrong... before we let go of a bad idea? Specific methodologies have capacity limits. We have no idea what the limits of the earth are, and our demographic trends strongly suggest that whatever those are, if they exist, our own habits will effect us long before we reach any conceptual wall. This is what is meant by the statement "earths carrying capacity is practically limitless". It's not to say that there isn't a number of people you could stuff in the earth to finally fill it up, nut to butt....with no room for another - it's the acknowledgement that we have no reason to believe that our population will ever outstrip it's ability to secure resources..in practice. We will self reduce. We will get sick. We will start wars. We will come up with some New Way™ to do x y or z. We will emigrate as productive realities constrain or empower us. Evemn though we find ourselves with so many more people today..we find ourselves in exactly the same predicament Malthus was in. He never would have believed that the uk could carry a fraction of it's pop..and the amusing thing is that we know that it's at least -possible- for it to carry many more than it does today. Will this take a reorganization of our technologies and priorities..yes..but we've done so for all of our history as human beings. Adapt or die.

(I can identify the silent malthusian assumptions in your data above, if you like, but I wonder if you might be able to identify them? Can you think of a reason why those statements might be wrong, today...or tomorrow? I think, for example, that your characterization of innovation being able to "stretch" the numbers is wildly understated. Historically, they certainly have been. Presently...I described a system to you with twice the primary productivity, an additional waste stream of edible protein completely absent from conventional production, no site specifications, and no parity of environmental impact - that is what intensification looks like. I note that, just as we've done in the past, we'll need to increase our population in order to achieve that intensification. We could do it through reproduction or through immigration. It's only an idea until we can secure enough human capital and labor. So, seeing as how the numbers above are based on a better utilization of current ag, I'd contend that we could safely double that number, at least..and that's just today - for the simple reason that if all currently used conventional land was used for this or it;s equivalents, instead, that would be the takeaway -and that;s ignoring the fact that the systrem I described doesn;t actually need to use that productive land..like I said, you can turn a parking lot into a farm nowadays. Tomorrow, we might be able to go even bigger. Any hard cap on our pop due to food and water is so distant and so difficult to pin down, that it makes it seem silly, to me, to give such focus to that instead of directly addressing those issues towards which pop reduction is a very dubious proposal. It's wrong..and it's the wrong message for the environmental movement to send, if we want it to succeed. We need to weed out those bits of antique cultishness so often repeated that they're taken for fact, blindsiding those advocates who are unaware of mutually exclusive and more well evidenced positions. Population pessimism is just pessimism. It's not scientific, and it's not a fact, and it's not a solution. It has it's roots and it's motivations in a political ideology - and I'm not saying that the ideology is all bad, or that they don't make valid points within it, mind..I'm just trying to give you a clearer picture of the field. )

That post was overpopulated with words and nobody is going to read it. I don’t know know if that proves anything or not.

[Alan V]

...

With all of that in mind, the newest face of population pessimism revolves around climate change.  Again the same assumptions are made..which have turned out to be both predictively and factual untrue time and time again.  Now, you'd think that people would get tired of predicting the apocalypse by any name...but, obviously, we don't.  It's an ancient pastime.  These advocates point to localized food shortage as justification for their assumptions..but as we discussed above, the failure of those assumptions and the identification of the cause of those shortages has since become a known know..and it's not overall population.  We could assume, like malthus in 1798..that "climate appropriate tech" is essentially fixed, in order to derive a theoretical carrying capacity.  We could assume, like the erlichs in the 60's, that nothing can be done to avert crisis beyond depopulation.

...

Population pessimism is just pessimism.  It's not scientific, and it's not a fact, and it's not a solution.  It has it's roots and it's motivations in a political ideology - and I'm not saying that the ideology is all bad, or that they don't make valid points within it, mind..I'm just trying to give you a clearer picture of the field. )

Calling something "pessimism" is an interesting rhetorical tactic. Yes, Ehrlich and others have been proven wrong. Do they represent everyone who is concerned about population? No.

Are scientists predicting the apocalypse? No, they are pointing out a big problem we need to fix, and soon, or we will suffer the consequences. I have read over 50 books on climate change and associated issues. The greatest unknown in climate change research is how humans will react. The scientists who model the future therefore create alternative scenarios based on the best available information and project (not predict) various possible outcomes. Uncertainties are built right into those projections. So first of all you are arguing against only certain individuals.

Second, I am not interested in betting the future of the planet on unproven technologies, or on an inductive assessment which depends entirely on the future playing out the same way as the past. I am interested in more conservative and proven tactics, since our need is immediate to combat climate change. We only have another 20 or 30 years to make significant progress before all those really nasty feedback mechanisms start kicking in, which may take the future of our climate out of our own hands.

Third, Malthusian assumptions have been proven in evolutionary theory and even historically in certain human societies, like Easter Island. You are more than disingenuous to over-simplify them so you can dismiss them altogether. Population is, and will continue to be, a multiplier of environmental impact. I = PAT. How scientific does one have to be to make a simple point? You are laughably calling real scientists unscientific.

In any case, this is almost a moot point. Population is leveling out in most parts of the world, and may in fact never reach 10 billion worldwide. Some areas will still have big problems with population, like central Africa and India, but population control will not be the most effective method we use to counteract climate change. We simply won't be able to change it quickly enough to have a useful impact.

[Mister Agenda]

That post was overpopulated with words and nobody is going to read it. I don’t know know if that proves anything or not.

Hmm. I read every word. I thought it was interesting.

[The Grand Nudger]

Calling something "pessimism" is an interesting rhetorical tactic.  Yes, Ehrlich and others have been proven wrong.  Do they represent everyone who is concerned about population?  No.

Are scientists predicting the apocalypse?  No, they are pointing out a big problem we need to fix, and soon, or we will suffer the consequences.  I have read over 50 books on climate change and associated issues.  The greatest unknown in climate change research is about how humans will react.  The scientists who model the future therefore create alternative scenarios based on the best available information and project (not predict) various possible outcomes.  Uncertainties are built right into those projections.  So first of all you are arguing against strawmen.

Second, I am not interested in betting the future of the planet on unproven technologies, or on an inductive assessment which depends entirely on the future playing out the same way as the past.  I am interested in more conservative and proven tactics, since our need is immediate to combat climate change.  We only have another 20 or 30 years to make significant progress before all those really nasty feedback mechanisms start kicking in, which may take the future of our climate out of our own hands.

Third, Malthusian assumptions have been proven in evolutionary theory and even historically in certain human societies.  You are more than disingenuous to over-simplify them so you can dismiss them altogether.  That's why I must conclude that you are not arguing in good faith at all, but only as a believer in the dogmas of technological optimism.

Population is, and will continue to be, a multiplier of environmental impact.  I = PAT.  How scientific does one have to be to make a simple and irrefutable point?  You are laughably calling real scientists unscientific.  What kind of scientist are you again?

That's just what the two opposing camps came to be called over the last couple centuries.  I didn't choose the names, and they do seem to fit.  

Moving onward, it's not just that erlich and others have been proven wrong...the fundamental assumptions upon which their estimates where based have been proven wrong.  That's why, ultimately, they were wrong..going all the way back to malthus and into the present day.  

No, climate scientists are not predicting the apocalypse, but population pessimists -are-.  That's the star around which population pessimism orbits - a malthusian catastrophe.  I'm not arguing against this assumption so much as pointing out both that and why it was mistaken.

No one suggests betting the future on unproven tech.  Population optimists point out that the future -relies- on intensification.  We have to make better and more productive use of our land regardless of our population.  This doesn't require unproven tech...and if you're not assuming that tomorrow will be like yesterday then you have no reason to assume that yesterdays yield from conventionals will be the same or smaller than tomorrows or that the population will continue to grow just because it has in thepst...in the first place. We can skip the positioning, lol.   

Malthus was an economist, his theory (1798) has nothing to do with evolutionary theory or evolutionary biology.  Darwin wouldn't write Origin until 1859.  Humanity has never outpaced it's rate of resource collection (the opposite occurred), and the cause of local shortage has been more accurately identified as incompetence, corruption, and global instability.   Malthus was wholly wrong, it is a myth that some science has "proved him right".....on anything. Hey, maybe, tommorrow, it will finally go the other way! That's a possibility!

The assumptions made in the formula provided have known flaws, are fundamentally pessimism biased, and fail to take into account the observations that contradict those assumptions just as much as any other form of population pessimism does.  More than this, there's no requirement that a pop optmist call them into question anyway. They would contend that changes to A and T are more direct and effective than changes to P, and that not all I is meaningfully problematic...is all.

No kind of scientist, by the way...I do fieldwork and build installations for land grant research into alternative ag.  Sort of buzz around people who know better picking up useful things. Which is a fancy way of saying I dig holes for a living....but, should that matter, and even more pedantically why should it matter when population optimism also has advocates well positioned and well regarded in academia? I gave you a factual description of the positions, and their flaws. I gave you a history of notables in the positions. I gave you present day examples that flatly contradict necessary assumptions. The pessimist contends, ultimately, that if we keep doing something some stupid way there is only so far that it can take us. I think we can all agree that this much is true, but in context of a hypothetical global carrying capacity it is a meaningless truth. The potential productivity of "stupid way to do something x" is a different subject than earths hypothetical ability to carry human life. This has always been the mistake central to pessmism, it's always been wrong..not only with respect to the then-future(now past) but even in a present moment. The way we grow our food is not the most productive known use of land, nor is it the most environmentally conscious. It is the most cost effective...itself an economic reality (Hi malthus...perhaps this might help to explain why he was interested), subject to change in the present and blind to future progress.

The productive capacity of pre columbian north american intercropping is no more the carrying capacity of the continent than yesterdays pre industrial fallow system..or today's industrial monoculture is.

[Alan V]

Sorry, but I don't find simple reiterations of "I'm right!" to be convincing, however wordy they are.

You don't understand what Malthus was saying. You don't understand what I = PAT even means in its application. You don't understand the concerns of over-population.

And you dismiss the work of real scientists as unscientific to exaggerate how obviously correct you are. I can't argue with that.

[The Grand Nudger]

Why do you think that population optimism is not a position of "real scientists"....honestly?

Yes, I've explained to you the many ways that population optimists have been right in contradiction to population pessimists. I didn't make them right, it's just historical trivia, lol.

http://lmgtfy.com/?q=population+optimism