Over population derail from "Humans as non-animals"

[T.G.G. Moogly]

Nature always seem to pull things into balance. Washout a vaccine COVID might have led to large scale population reduction.

That depends on whether you think 8 billion humans is actually environmentally "balanced" for the planet. I have a friend who maintains that climate and nature is "self-correcting" for humans, that nothing we do can threaten us. I too am a trillionaire in my dreams.

 

[Swammerdami]

Nature always seem to pull things into balance. Washout a vaccine COVID might have led to large scale population reduction.

That depends on whether you think 8 billion humans is actually environmentally "balanced" for the planet. I have a friend who maintains that climate and nature is "self-correcting" for humans, that nothing we do can threaten us. I too am a trillionaire in my dreams.

The high population is unsustainable. Levels of water tables are plummeting in India and elsewhere. Feeding the many billions relies on huge consumption of phosphate fertilizer; but easily recoverable phosphate is fast being exhausted. An increasing portion of the Earth's fertile surface is now used to grow food for humans (or the beef they like to eat); this impacts biodiversity — in fact scientists are already calling out time The Sixth Great Extinction.

The ocean is being degraded horribly; there are giant piles of plastic in the middle of oceans; coral reefs are being destroyed. Parts of the ocean once dominated by fish are now dominated by jellyfish.

IMO, climate change is just one of several problems that can be directly attributed to human over-population.

 

[T.G.G. Moogly]

Nature always seem to pull things into balance. Washout a vaccine COVID might have led to large scale population reduction.

That depends on whether you think 8 billion humans is actually environmentally "balanced" for the planet. I have a friend who maintains that climate and nature is "self-correcting" for humans, that nothing we do can threaten us. I too am a trillionaire in my dreams.

The high population is unsustainable. Levels of water tables are plummeting in India and elsewhere. Feeding the many billions relies on huge consumption of phosphate fertilizer; but easily recoverable phosphate is fast being exhausted. An increasing portion of the Earth's fertile surface is now used to grow food for humans (or the beef they like to eat); this impacts biodiversity — in fact scientists are already calling out time The Sixth Great Extinction.

The ocean is being degraded horribly; there are giant piles of plastic in the middle of oceans; coral reefs are being destroyed. Parts of the ocean once dominated by fish are now dominated by jellyfish.

IMO, climate change is just one of several problems that can be directly attributed to human over-population.

People have different aspirations. There are posters on this board that honestly think 30 billion humans is perfectly okay. Maybe it is okay if all you want are humans, air conditioners and sidewalks and roads and nothing else. I can't imagine being content in such a vast wasteland. It would be like everyone living in a nursing home.

 

[rousseau]

At the broadest level the adaptations we've had have allowed us to extract energy from the environment with increasing intensity. I came across a term in the past few months that I can't remember, but it basically denoted ability to extract energy via tools. Unlike other species, we're very good at using tools to extract energy from the environment.

If you completely forget any ideas about us as special, and instead look at us as very effective converters of energy, then what we see today is about the consequence you'd get. A degrading environment, and a biosphere wide reaction (climate change) to our history and growth.

And yet culturally we're still stuck in the perspective of reason being the defining feature of our species. Some of us have just emerged from chaos just a few centuries ago due to the enlightenment, and this is generally regarded as a good thing, but most of the long-term damage we've done has happened since then.

 

[bilby]

The high population is unsustainable. Levels of water tables are plummeting in India and elsewhere. Feeding the many billions relies on huge consumption of phosphate fertilizer; but easily recoverable phosphate is fast being exhausted. An increasing portion of the Earth's fertile surface is now used to grow food for humans (or the beef they like to eat); this impacts biodiversity — in fact scientists are already calling out time The Sixth Great Extinction.

The ocean is being degraded horribly; there are giant piles of plastic in the middle of oceans; coral reefs are being destroyed. Parts of the ocean once dominated by fish are now dominated by jellyfish.

IMO, climate change is just one of several problems that can be directly attributed to human over-population.

People have different aspirations. There are posters on this board that honestly think 30 billion humans is perfectly okay. Maybe it is okay if all you want are humans, air conditioners and sidewalks and roads and nothing else. I can't imagine being content in such a vast wasteland. It would be like everyone living in a nursing home.

30 billion humans is about three times the plausible maximum number that will ever simultaneously inhabit the planet, so it's completely irrelevant to reality whether or not that population is OK.

Overpopulation is a stupid idea. It was a reasonable fear in the mid to late twentieth century, but it's long since been resolved.

There are no resource issues we cannot solve that would prevent us sustaining the ~10 billion humans that represent our likely peak population. Of course, we might not be smart enough to actually implement those solutions - look at the reluctance we have to completely replace the burning of fossil fuels with nuclear fission - but the problems are political and ideological, they're not resource, technology, or population driven.

Population is just people. "Overpopulation" is a fundamentally anti-human concept, and belongs in the same ideological dustbin as other anti-humanitarian ideas such as apartheid, slavery, and fascism.

 

[T.G.G. Moogly]

At the broadest level the adaptations we've had have allowed us to extract energy from the environment with increasing intensity. I came across a term in the past few months that I can't remember, but it basically denoted ability to extract energy via tools. Unlike other species, we're very good at using tools to extract energy from the environment.

If you completely forget any ideas about us as special, and instead look at us as very effective converters of energy, then what we see today is about the consequence you'd get. A degrading environment, and a biosphere wide reaction (climate change) to our history and growth.

And yet culturally we're still stuck in the perspective of reason being the defining feature of our species. Some of us have just emerged from chaos just a few centuries ago due to the enlightenment, and this is generally regarded as a good thing, but most of the long-term damage we've done has happened since then.

That damage has always occurred, it's only become more apparent with the rise in population. That rise in population can be attributed to natural selection and our propensity to want to devour resources that belong to the smaller population down the river or up the river. The clan that had the most bodies generally won the contests.

When people do unite, as we have in the U.S., it's typically in mutual hatred or fear of an outside threat. It's ironic that we can unite to carry out our collective hatred and fear. So maybe the current problem is there is nothing out there to unite us and so we have to manufacture enemies from within.

But I still think it's a population thing, there are just too many people crowded together in competition for resources and it's affecting behavior, just as it does in other primates.

 

[bilby]

At the broadest level the adaptations we've had have allowed us to extract energy from the environment with increasing intensity. I came across a term in the past few months that I can't remember, but it basically denoted ability to extract energy via tools. Unlike other species, we're very good at using tools to extract energy from the environment.

If you completely forget any ideas about us as special, and instead look at us as very effective converters of energy, then what we see today is about the consequence you'd get. A degrading environment, and a biosphere wide reaction (climate change) to our history and growth.

And yet culturally we're still stuck in the perspective of reason being the defining feature of our species. Some of us have just emerged from chaos just a few centuries ago due to the enlightenment, and this is generally regarded as a good thing, but most of the long-term damage we've done has happened since then.

Extracting energy from the environment is a good thing. Burning fossil fuels isn't. The two are not the same.

Extracting energy from the environment isn't a defining feature of humans; It's a defining feature of life.

 

[rousseau]

At the broadest level the adaptations we've had have allowed us to extract energy from the environment with increasing intensity. I came across a term in the past few months that I can't remember, but it basically denoted ability to extract energy via tools. Unlike other species, we're very good at using tools to extract energy from the environment.

If you completely forget any ideas about us as special, and instead look at us as very effective converters of energy, then what we see today is about the consequence you'd get. A degrading environment, and a biosphere wide reaction (climate change) to our history and growth.

And yet culturally we're still stuck in the perspective of reason being the defining feature of our species. Some of us have just emerged from chaos just a few centuries ago due to the enlightenment, and this is generally regarded as a good thing, but most of the long-term damage we've done has happened since then.

Extracting energy from the environment is a good thing. Burning fossil fuels isn't. The two are not the same.

Extracting energy from the environment isn't a defining feature of humans; It's a defining feature of life.

Extracting energy from the environment with increasing intensity.

 

[bilby]

At the broadest level the adaptations we've had have allowed us to extract energy from the environment with increasing intensity. I came across a term in the past few months that I can't remember, but it basically denoted ability to extract energy via tools. Unlike other species, we're very good at using tools to extract energy from the environment.

If you completely forget any ideas about us as special, and instead look at us as very effective converters of energy, then what we see today is about the consequence you'd get. A degrading environment, and a biosphere wide reaction (climate change) to our history and growth.

And yet culturally we're still stuck in the perspective of reason being the defining feature of our species. Some of us have just emerged from chaos just a few centuries ago due to the enlightenment, and this is generally regarded as a good thing, but most of the long-term damage we've done has happened since then.

That damage has always occurred, it's only become more apparent with the rise in population. That rise in population can be attributed to natural selection and our propensity to want to devour resources that belong to the smaller population down the river or up the river. The clan that had the most bodies generally won the contests.

When people do unite, as we have in the U.S., it's typically in mutual hatred or fear of an outside threat. It's ironic that we can unite to carry out our collective hatred and fear. So maybe the current problem is there is nothing out there to unite us and so we have to manufacture enemies from within.

But I still think it's a population thing, there are just too many people crowded together in competition for resources and it's affecting behavior, just as it does in other primates.

Crowding and population are totally different things. There's a lot of empty space on the planet, but people don't want to live there. Humans like cities. The number of people who don't live in cities has plummeted since the Industrial revolution, and in the developed world the rural areas have lower population densities than at any time in recorded history.

Overpopulation is one of those things that everyone knows. Just like everyone knows that airliners and nuclear power are dangerous; That an object in motion requires a continuous application of force or it will come to a stop; And that there are gods who guide the forces of nature.

These things are obvious, popular, undoubted, and wrong.

 

[rousseau]

Can we not do this conversation about over-population again? It's been done over and over again every time someone mentions the term. I don't mind, but if it continues I'll likely request a split.

 

[bilby]

At the broadest level the adaptations we've had have allowed us to extract energy from the environment with increasing intensity. I came across a term in the past few months that I can't remember, but it basically denoted ability to extract energy via tools. Unlike other species, we're very good at using tools to extract energy from the environment.

If you completely forget any ideas about us as special, and instead look at us as very effective converters of energy, then what we see today is about the consequence you'd get. A degrading environment, and a biosphere wide reaction (climate change) to our history and growth.

And yet culturally we're still stuck in the perspective of reason being the defining feature of our species. Some of us have just emerged from chaos just a few centuries ago due to the enlightenment, and this is generally regarded as a good thing, but most of the long-term damage we've done has happened since then.

Extracting energy from the environment is a good thing. Burning fossil fuels isn't. The two are not the same.

Extracting energy from the environment isn't a defining feature of humans; It's a defining feature of life.

Extracting energy from the environment with increasing intensity.

Which is a very good thing. If you want to rank standard of living, at almost any level of granularity, the intensity of energy use is in almost perfect lockstep with that ranking.

Intensity of energy use is inseparable from quality of life.

 

[bilby]

Can we not do this conversation about over-population again? It's been done over and over again every time someone mentions the term. I don't mind, but if it continues I'll likely request a split.

I agree, it shouldn't be necessary. But apparently, it is. Because people who should know better still espouse this dead and deadly ideology.

Fortunately, like the racism from which it sprouted, and the religion which it emulates intellectually, the overpopulation idea seems to be mostly a feature of older people, so there's some hope that it might become less virulent over time.

But (just like those other bad ideas) it won't go away if it's allowed to stand unchallenged when raised as though it were a self-evident truth.

 

[rousseau]

Extracting energy from the environment with increasing intensity.

Which is a very good thing. If you want to rank standard of living, at almost any level of granularity, the intensity of energy use is in almost perfect lockstep with that ranking.

Intensity of energy use is inseparable from quality of life.

bilby you're clearly a smart guy, but oft-times these perspectives can come across like the same blinding faith in reason that Europeans had at the turn of the twentieth century, while completely blind to the unintended consequences of their own actions at the time.

You promote nuclear energy which is fair, it seems to be the main avenue out of our current predicament, but have you ever looked at potential and unforeseen long-term consequences of nuclear, exactly like we didn't see when we started seeing fossil fuels? I'm not saying they're there, but that's the point, if they are there they may be unforeseen. We don't always know the long-term consequences of decisions we're making now.

Given that, you seem to be of the opinion that we can just keep extracting from the environment with no upper limit. But the problem is that our biosphere is a closed system. And the truth is none of us really know what the world is going to look like in 1000 years, but what we do know is that we're already doing pretty serious damage to pretty much every global ecosystem.

 

[bilby]

Extracting energy from the environment with increasing intensity.

Which is a very good thing. If you want to rank standard of living, at almost any level of granularity, the intensity of energy use is in almost perfect lockstep with that ranking.

Intensity of energy use is inseparable from quality of life.

bilby you're clearly a smart guy, but oft-times these perspectives can come across like the same blinding faith in reason that Europeans had at the turn of the twentieth century, while completely blind to the unintended consequences of their own actions at the time.

You promote nuclear energy which is fair, it seems to be the main avenue out of our current predicament, but have you ever looked at potential and unforeseen long-term consequences of nuclear, exactly like we didn't see when we started seeing fossil fuels? I'm not saying they're there, but that's the point, if they are there they may be unforeseen. We don't always know the long-term consequences of decisions we're making now.

Given that, you seem to be of the opinion that we can just keep extracting from the environment with no upper limit. But the problem is that our biosphere is a closed system. And the truth is none of us really know what the world is going to look like in 1000 years, but what we do know is that we're already doing pretty serious damage to pretty much every global ecosystem.

Given that this entire sub-discussion is me arguing that there IS a limit, that's a bit rich.

Human population will peak. If ten billion people have an excellent standard of living, the demand for further energy use will plateau.

Invoking unknown and unforeseen risks is the hallmark of a person with no rational objection. It's pascal's wager for anti-nuclear campaigners, anti-population campaigners, and other neo-luddites who have no reason for their fears, but are damned if they'll let that stop them from being afraid of the unnatural.

Unnatural is all that stands between us and life expectancy at birth of ~40 years, with those years spent mostly hungry, cold, and tired.

 

[rousseau]

bilby you're clearly a smart guy, but oft-times these perspectives can come across like the same blinding faith in reason that Europeans had at the turn of the twentieth century, while completely blind to the unintended consequences of their own actions at the time.

You promote nuclear energy which is fair, it seems to be the main avenue out of our current predicament, but have you ever looked at potential and unforeseen long-term consequences of nuclear, exactly like we didn't see when we started seeing fossil fuels? I'm not saying they're there, but that's the point, if they are there they may be unforeseen. We don't always know the long-term consequences of decisions we're making now.

Given that, you seem to be of the opinion that we can just keep extracting from the environment with no upper limit. But the problem is that our biosphere is a closed system. And the truth is none of us really know what the world is going to look like in 1000 years, but what we do know is that we're already doing pretty serious damage to pretty much every global ecosystem.

Given that this entire sub-discussion is me arguing that there IS a limit, that's a bit rich.

Human population will peak. If ten billion people have an excellent standard of living, the demand for further energy use will plateau.

Invoking unknown and unforeseen risks is the hallmark of a person with no rational objection. It's pascal's wager for anti-nuclear campaigners, anti-population campaigners, and other neo-luddites who have no reason for their fears, but are damned if they'll let that stop them from being afraid of the unnatural.

Unnatural is all that stands between us and life expectancy at birth of ~40 years, with those years spent mostly hungry, cold, and tired.

The proper response to unforeseen risks wouldn't be mockery, it would be trying to understand those unforeseen risks and adapting to them. But as we're still trying to convince most people that Trump isn't an appropriate leader for a major country, and that heaven doesn't exist, we've got a problem when it comes to serious strategy about our future.

 

[bilby]

bilby you're clearly a smart guy, but oft-times these perspectives can come across like the same blinding faith in reason that Europeans had at the turn of the twentieth century, while completely blind to the unintended consequences of their own actions at the time.

You promote nuclear energy which is fair, it seems to be the main avenue out of our current predicament, but have you ever looked at potential and unforeseen long-term consequences of nuclear, exactly like we didn't see when we started seeing fossil fuels? I'm not saying they're there, but that's the point, if they are there they may be unforeseen. We don't always know the long-term consequences of decisions we're making now.

Given that, you seem to be of the opinion that we can just keep extracting from the environment with no upper limit. But the problem is that our biosphere is a closed system. And the truth is none of us really know what the world is going to look like in 1000 years, but what we do know is that we're already doing pretty serious damage to pretty much every global ecosystem.

Given that this entire sub-discussion is me arguing that there IS a limit, that's a bit rich.

Human population will peak. If ten billion people have an excellent standard of living, the demand for further energy use will plateau.

Invoking unknown and unforeseen risks is the hallmark of a person with no rational objection. It's pascal's wager for anti-nuclear campaigners, anti-population campaigners, and other neo-luddites who have no reason for their fears, but are damned if they'll let that stop them from being afraid of the unnatural.

Unnatural is all that stands between us and life expectancy at birth of ~40 years, with those years spent mostly hungry, cold, and tired.

The proper response to unforeseen risks wouldn't be mockery, it would be trying to understand those unforeseen risks and adapting to them. But as we're still trying to convince most people that Trump isn't an appropriate leader for a major country, and that heaven doesn't exist, we've got a problem when it comes to serious strategy about our future.

By definition, unforeseen risks cannot be identified and planned for.

If you're invoking them as a reason for caution, then that's fine; Caution in all things is a good idea.

But invoking them as a reason for action or inaction is soundly deserving of mockery. As I said, it's Pascal's wager.

 

[rousseau]

The proper response to unforeseen risks wouldn't be mockery, it would be trying to understand those unforeseen risks and adapting to them. But as we're still trying to convince most people that Trump isn't an appropriate leader for a major country, and that heaven doesn't exist, we've got a problem when it comes to serious strategy about our future.

By definition, unforeseen risks cannot be identified and planned for.

This is untrue. They're unforeseen because we're not looking for them, we're in an endless game of whack-a-mole where we come up with an ad-hoc solution to yesterday's problem before we get trampled by a herd of elephants.

When cars were invented nobody was thinking - maybe in 100 years the entire world's infrastructure will be locked into this invention. They just wanted to get their groceries faster. And this is the essential problem, we develop solutions to immediate problems without adequately addressing potential consequences. We can barely convince people to address problems we already know about, and oftentimes when we do address problems our solutions aren't even helpful.

I absolutely am not invoking this as a reason for inaction, I'm highlighting the fact that you seem to have faith in our progress via immediate solutions, but possibly aren't considering how today's solution becomes tomorrow's problem. To me this is a reason for pessimism over the fact that our species extracts energy with increasing intensity. The fundamental thing that we are good at is exploiting our own environment, and I'm not convinced that there's any great path out of it. This is just the arc of our species' history on our planet.

 

[Swammerdami]

Nobody has a plan to sharply reduce human population in the short term, so the following comments are purely hypothetical — a thought experiment.

Question: If the choice is between a world of 10 billion happy humans and a world with 5 billion happy humans, is it fair to say the former has a humanity that's twice as happy? This is a philosophical question with, perhaps, no easy answer. I would answer No, but perhaps many would say Yes. The Yes-sayers may stop reading after the next paragraph; my comments aren't addressed at them.

A world with fewer happy humans will have more happy squirrels, happy dolphins, happy birds, happy insects and happy fish but some will find this suggestion silly. However, many would agree that humans would be happier in a world where other creatures thrive. Why do some promote a 10-gigahuman world? In what sense is it better than a 5-gigahuman world? Or is it just about accepting the inevitable: There will be a high population so let's hope it's for the best.

Some say that with ten billion instead of five billion, we'll have twice as many geniuses like Mozart and twice as many like Archimedes. This fails the sniff test! There were less than a billion humans alive in Mozart's time, and perhaps just 100 million in Archimedes' time. Yet both these great geniuses are still spoken of in superlative terms.

The problems of overpopulation are not hypothetical: We can see them now.. Precious resources are being depleted: groundwater, phosphates and petroleum are among the most obvious examples. About fifty species of life already go extinct every week during this Great Man-made Extinction and this number is increasing. Even without extinctions, there are profound changes to the ecology: I've already mentioned the widespread replacement of fish with jellyfish.

I'm sure that the supporters of overpopulation have glib answers to these concerns. Fusion power will provide the huge energy needed to replenish phosphates and groundwater. Extinctions are not a concern: only H. sapiens matters. And clever chefs will find ways to prepare varieties of jellyfish as delicious as fish. I find these answers overly glib. Groundwater depletion is already a serious concern in many parts of the world; a huge portion of arable land is already dedicated to humans and their food; pollution of various sorts is already a big problem. And extinctions are irreversible.

Overpopulation is a stupid idea. It was a reasonable fear in the mid to late twentieth century, but it's long since been resolved.

There are no resource issues we cannot solve that would prevent us sustaining the ~10 billion humans that represent our likely peak population. Of course, we might not be smart enough to actually implement those solutions - look at the reluctance we have to completely replace the burning of fossil fuels with nuclear fission - but the problems are political and ideological, they're not resource, technology, or population driven.

Population is just people. "Overpopulation" is a fundamentally anti-human concept, and belongs in the same ideological dustbin as other anti-humanitarian ideas such as apartheid, slavery, and fascism.

You acknowledge that 30 billion would be too much; that leaves me confused about your strong support for 10 billion. Especially since you admit that there may be obstacles to the dramatic changes needed to sustain such a population. Are you especially fond of jellyfish as a food?

 

[Politesse]

The problems of overpopulation are not hypothetical: We can see them now.. Precious resources are being depleted: groundwater, phosphates and petroleum are among the most obvious examples. About fifty species of life already go extinct every week during this Great Man-made Extinction and this number is increasing. Even without extinctions, there are profound changes to the ecology: I've already mentioned the widespread replacement of fish with jellyfish.

Nobody has ever denied that over-exploitation of natural resources is a problem. The accusation is that the true perpetrators of the crimes are using "overpopulation" as a smoke-screen. It blames the urban poor of third-world nations (who don't actually benefit much from the destruction of wide swaths of the environment in search of oil) for the decisions made by global elites for their own selfish reasons. We aren't obliged to destroy our planet because that's the only way to feed all the people on it, we choose to destroy the planet because doing do is profitable in the short term. The populations that make those decisions aren't the same ones whose family size is growing at present. Those who personally consume the most resources are, in fact, the least likely to have large families. It is a fact well-established that wealth and family size are negatively correlated, and vice versa. So killing or sterilizing a bunch of disadvantaged people is not going to do anything to solve the ecological crisis. They are the excuse for, not the cause of, ecological destruction.

 

[bilby]

Nobody has a plan to sharply reduce human population in the short term, so the following comments are purely hypothetical — a thought experiment.

Question: If the choice is between a world of 10 billion happy humans and a world with 5 billion happy humans, is it fair to say the former has a humanity that's twice as happy? This is a philosophical question with, perhaps, no easy answer. I would answer No, but perhaps many would say Yes. The Yes-sayers may stop reading after the next paragraph; my comments aren't addressed at them.

A world with fewer happy humans will have more happy squirrels, happy dolphins, happy birds, happy insects and happy fish but some will find this suggestion silly. However, many would agree that humans would be happier in a world where other creatures thrive. Why do some promote a 10-gigahuman world? In what sense is it better than a 5-gigahuman world? Or is it just about accepting the inevitable: There will be a high population so let's hope it's for the best.

Some say that with ten billion instead of five billion, we'll have twice as many geniuses like Mozart and twice as many like Archimedes. This fails the sniff test! There were less than a billion humans alive in Mozart's time, and perhaps just 100 million in Archimedes' time. Yet both these great geniuses are still spoken of in superlative terms.

The problems of overpopulation are not hypothetical: We can see them now.. Precious resources are being depleted: groundwater, phosphates and petroleum are among the most obvious examples. About fifty species of life already go extinct every week during this Great Man-made Extinction and this number is increasing. Even without extinctions, there are profound changes to the ecology: I've already mentioned the widespread replacement of fish with jellyfish.

I'm sure that the supporters of overpopulation have glib answers to these concerns. Fusion power will provide the huge energy needed to replenish phosphates and groundwater. Extinctions are not a concern: only H. sapiens matters. And clever chefs will find ways to prepare varieties of jellyfish as delicious as fish. I find these answers overly glib. Groundwater depletion is already a serious concern in many parts of the world; a huge portion of arable land is already dedicated to humans and their food; pollution of various sorts is already a big problem. And extinctions are irreversible.

Overpopulation is a stupid idea. It was a reasonable fear in the mid to late twentieth century, but it's long since been resolved.

There are no resource issues we cannot solve that would prevent us sustaining the ~10 billion humans that represent our likely peak population. Of course, we might not be smart enough to actually implement those solutions - look at the reluctance we have to completely replace the burning of fossil fuels with nuclear fission - but the problems are political and ideological, they're not resource, technology, or population driven.

Population is just people. "Overpopulation" is a fundamentally anti-human concept, and belongs in the same ideological dustbin as other anti-humanitarian ideas such as apartheid, slavery, and fascism.

You acknowledge that 30 billion would be too much; that leaves me confused about your strong support for 10 billion. Especially since you admit that there may be obstacles to the dramatic changes needed to sustain such a population. Are you especially fond of jellyfish as a food?

I acknowledged no such thing.

I merely pointed out that 30 billion will never happen, so it's futile to worry about whether or not that would be too many.

I neither know nor care whether 30 billion is able to be supported on Earth, because it's clear that 15 billion can, and that we are highly unlikely ever to reach that number.

Nothing is being depleted, except biodiversity; And biodiversity depletion is not due to sheer numbers of humans - we did more of it when there were fewer of us.

Every resource except Helium and the components of deep space probes that was on Earth before humans is still here today. We can, with sufficient cheap energy, recycle any and all of it - we don't, because it's cheaper to just dig up fresh stuff.

There's enough cheap, clean energy to meet our needs in seawater uranium alone; And obviously there's also terrestrial uranium, thorium, and other actinides out there, all of which can be burned by fast reactors. We don't need fusion (which is good, because it may never be practical). We don't need to worry about stuff running out; We just need to do something about it - if, as, and when it becomes an issue.

Most people have trouble believing this. But it remains true nevertheless.