Too many people?

[rousseau]

And climate change is disrupting supply lines and leading to more severe and frequent weather events in the African Sahel.

Well, that's certainly true. When you have a city of three million people, in a region with annual rainfall of only 100-150mm (a figure that has declined recently due in large part to climate change), the surrounding countryside simply cannot possibly produce enough food for everyone, and starvation and poverty are the inevitable consequence.

Oh, wait. Sorry, those are the figures for Las Vegas, Nevada, which isn't currently the subject of any World Food Programme Emergency status.

So why is Las Vegas not the centre of a famine stricken disaster zone?

Why can't we make the Sahel more like Arizona or Nevada to live in? The answer clearly isn't solely to do with either climate or population density. It's more complicated than that. Much more complicated.

But it's much more easy to just declare that these damn Nevadans Africans just need to stop breeding like rabbits, than it is to actually come up with real ways to move from one condition to the other.

Maybe we should open some casinos in Eritrea, or Burkina Faso, or The Gambia.

It's a cinch that in a place where farming is difficult, it's a poor idea to try to base the economy on farming. There are lots of very wealthy and very arid places in the world; And even more places that are incredibly wealthy without any possible way to grow enough food for everyone to eat.

The solution to the inability of Sudanese people to grow sufficient food is the exact same solution I use personally, to address the self same problem that I too am not able to grow my own food. I do something else that people pay me to do, and use the money to buy food from people who are good at producing it, and who have the land, climate, tools and skills necessary to specialise in it.

The world is currently producing more food than is necessary to overfeed absolutely everyone currently alive. More people worldwide suffer health problems due to overeating than suffer due to lack of food.

There's no food shortage; There's just a distribution of wealth problem. And if you think that dramatically lower population levels would help with distribution of wealth, you're probably not aware of the history of humanity.

When population levels were far lower, people still starved while their kings ate like, well, kings.

If you accept that climate change is at least indirectly related to population density and size, then the reality is that population is causing us real problems, at least at this point in time.

You'll get no argument from me about your proposed solutions, but we are still left with people who are particularly adept at degrading the environment. Whether the population is 2, 5, or 10 billion I don't see that ever not being a problem.

So maybe the larger problem is - how can a species that's good at exploiting the environment live sustainably. Nuclear is an immediate option, but I don't think it solves the long term problem.

 

[bilby]

If you accept that climate change is at least indirectly related to population density

Insofar as population density matters at all, it's a good thing - dense populations use less energy than equal populations that are more dispersed.

 

[Merle]

I don’t understand your argument. Cutting all those per person amounts in half is not the same thing as cutting prosperity in half unless you assume technological change or productivity increases are not possible.

Of course changes in technology affect the amount of impact we have on the environment for a given level of prosperity. That's obvious. It has nothing to do with my point.

Once again, consider two scenarios in the distant future. In both scenarios the exact same level of technology is available. In scenario 1, there are n people with each having x impact on the environment. In scenario 2, there are 2n people with each having x/2 impact on the environment. Both have the same impact on the environment, nx. But those in scenario 1 have a much higher level of physical prosperity per person.

The total impact on the environment depends on both factors.

 

[Merle]

dense populations use less energy.

Interesting. I would have thought smart populations used less energy.

 

[Merle]

The number of generations that would be required to reach 2 billion, with a general fertility rate of ~1.7 per woman (the current rate in the USA) is surprisingly small;

A quick calculation shows it would take 9 generations, which is something like 200 years.

Assume there are three generations of 2.33 billion people each alive today. Every 25 years assume the oldest generation dies and the youngest generation creates a new generation of x times the size of their generation, depending on the birth rate. If x = 0.85, I find the size of each generation (in billions of people) would be as listed below.

1 2.33
2 2.33
3 2.33
4 1.98
5 1.68
6 1.43
7 1.22
8 1.03
9 0.88
10 0.75
11 0.63
12 0.54

Only when we get to the ninth iteration (generations 10-12 alive) do we get less than 2 billion people.

 

[bilby]

The number of generations that would be required to reach 2 billion, with a general fertility rate of ~1.7 per woman (the current rate in the USA) is surprisingly small;

A quick calculation shows it would take 9 generations, which is something like 200 years.

Assume there are three generations of 2.33 billion people each alive today. Every 25 years assume the oldest generation dies and the youngest generation creates a new generation of x times the size of their generation, depending on the birth rate. If x = 0.85, I find the size of each generation (in billions of people) would be as listed below.

1 2.33
2 2.33
3 2.33
4 1.98
5 1.68
6 1.43
7 1.22
8 1.03
9 0.88
10 0.75
11 0.63
12 0.54

Only when we get to the ninth iteration (generations 10-12 alive) do we get less than 2 billion people.

There you go. Problem solved.

 

[laughing dog]

I don’t understand your argument. Cutting all those per person amounts in half is not the same thing as cutting prosperity in half unless you assume technological change or productivity increases are not possible.

Of course changes in technology affect the amount of impact we have on the environment for a given level of prosperity. That's obvious. It has nothing to do with my point.

Once again, consider two scenarios in the distant future. In both scenarios the exact same level of technology is available. In scenario 1, there are n people with each having x impact on the environment. In scenario 2, there are 2n people with each having x/2 impact on the environment. Both have the same impact on the environment, nx. But those in scenario 1 have a much higher level of physical prosperity per person.

Only if you assume that in scenario 2, that productivity is half (or less) as much as it is in scenario one.

The total impact on the environment depends on both factors.

That assumes a static economic and social environment. Your scenario is constructed by assumption to lead to a specific conclusion.

 

[Jarhyn]

I don’t understand your argument. Cutting all those per person amounts in half is not the same thing as cutting prosperity in half unless you assume technological change or productivity increases are not possible.

Of course changes in technology affect the amount of impact we have on the environment for a given level of prosperity. That's obvious. It has nothing to do with my point.

Once again, consider two scenarios in the distant future. In both scenarios the exact same level of technology is available. In scenario 1, there are n people with each having x impact on the environment. In scenario 2, there are 2n people with each having x/2 impact on the environment. Both have the same impact on the environment, nx. But those in scenario 1 have a much higher level of physical prosperity per person.

Only if you assume that in scenario 2, that productivity is half (or less) as much as it is in scenario one.

The total impact on the environment depends on both factors.

That assumes a static economic and social environment. Your scenario is constructed by assumption to lead to a specific conclusion.

Not to mention that much of human impact amounts to economies of scale: for many things, twice as much costs a quarter more to produce, so long as the regional economy is willing to accept opportunity costs for scaling their primary exports.

Other times twice as much costs 4 times more.

As far as I know most products are kind of like that at various production ranges, and there's a sweet spot just before the break even point where the economy of scale starts to drop off.

There are situations that can be expected where if we were supplying half as much, it might be just as expensive.

Or, 1 custom printed circuit board will cost you $5000. 500 printed circuit boards will ALSO cost you $5000. 5000 printed circuit board... Will cost you $6000.

 

[Merle]

There you go. Problem solved.

Uh, assuming you have 200 years to make the correction, and assuming you can reach that average birthrate across the globe. The global average is 2.3 births per woman, which is a long way from your figure. ( see https://data.worldbank.org/indicator/SP.DYN.TFRT.IN )

Last year 134 million people were born, and 67 million people died, so we are a long way from the condition where population starts declining. (https://ourworldindata.org/births-and-deaths)

 

[bilby]

Uh, assuming you have 200 years to make the correction,

Why would you assume we don't?

and assuming you can reach that average birthrate across the globe.

Why would you assume we can't?

 

[Jarhyn]

Uh, assuming you have 200 years to make the correction,

Why would you assume we don't?

and assuming you can reach that average birthrate across the globe.

Why would you assume we can't?

I mean, if we just empower people to make the decision to not have kids, by limiting how vasectomies and tubal ligations and gonadectomies may be handled by doctors such that refusal on grounds of "you may change your mind" becomes uninsurable malpractice following a 6 month waiting period, I'm pretty sure we can easily surpass that cut in birth rates.

Maybe go to covering abortions with government funds as well.

 

[Loren Pechtel]

The next question is how much time we have available to reach that goal. If resource depletion, pollution, and global warming could indeed lead to the extinction of Homo sapiens in a century, one would think we should try to reach sustainable limits well before that, so let’s use 80 years as our timeframe. If we want a sustainable population 80 years from now, and the average lifespan is 72 years, then we would have 8 years to ramp the birthrate down to sustainable levels.

Do we have far longer than 80 years to reach a sustainable population? Can the planet sustainably hold far more than 2 billion people? Or is the situation indeed as dire for our near descendants as those figures suggest? Should we really target reducing the birthrate 80% within the next 8 years?

This is assuming there is a sustainable population in the first place. I do not believe the concept exists at current (or any lower) technology level. The only question is how fast resources are depleted--all the "green" approaches simply push the resource collapse point beyond the edge of the chart.

The only long term solution is technological. Note that all of the "overpopulation" problems currently facing Earth can be addressed with sufficient energy--there is no problem that can't be addressed. The question becomes whether we can develop solutions before we crash.

(And, yes, it might not be possible to do so fast enough--this might be the Great Filter.)

 

[Loren Pechtel]

The thing is that a catastrophic global warming scenario isn't that bad. Humans are extremely adaptible. Yes, the water level is catastrophic. Food production will change. Our living arrangements and living space will be much limitted. But we'll be fine. We've been through a lot worse.

Disagree--the catastrophic scenarios will make much of the world uninhabitable. If it happens fast enough we won't be able to relocate everyone in time.

Niether China or India care about the environment. They're more focused on keeping their citizens alive now. So almost half of the world's populartion have more pressing needs than environmentalism and caring about the future.

Even in the west we have a split opinion on it. Conservatives don't care about the environment. Unless we have a massive majority opinion on the side of environmentalism, we're not going to fix this.

It's not a question of being stupid. It's simply a question of political realities.

Unfortunately, true. Few people care about the situation beyond their lifespan--and the people in power are usually reasonably old.

 

[bilby]

The only long term solution is technological. Note that all of the "overpopulation" problems currently facing Earth can be addressed with sufficient energy--there is no problem that can't be addressed.

Indeed.



https://xkcd.com/1162

 

[Loren Pechtel]

There's a lot of denial out there. Denial even that any problem exists. Denial based on the idea of 'we'll find a way, we always do/ science/technology will save us'. That will be hard to overcome. I think we will see no action until the threat is fully on us.

The issue is that the planet is pretty big. So there are a lot of resources. Rarer sources will be an issue, but that revolves around electric battery design, MRIs, and what not. The big stuff, water, air, and food... we've got it (or the tech to make it happen exists today). And the more people there are, the more there are to increase access to these things.

Everything is available, the question is how much material you have to deal with to extract it. If you can throw enough energy at it a calutron can separate out anything. (Admittedly, the energy requirements are very, very high to do it on an industrial scale. While there is no reducing the required currents I suspect it could be done at a lot lower voltage and thus with a lot less energy than has previously been done.)

 

[Loren Pechtel]

Sure, Ehrlich did not foresee the results that the Green Revolution would have. But this revolution has relied heavily on artificial fertilizers and great quantities of oil and natural gas. The best sources of these nonrenewable resources will someday be gone. The issue is how we can maintain sufficient food production when these supplies are gone.

Ehrlich had two fundamental failures, but this isn't one of them. The green revolution postpones the day of reckoning, it doesn't change the basic problem.

Where he missed badly is that industrialization and the availability of contraception drives down the birth rate, within a lifespan it drops to below-replacement. Second, his "solution" is not a solution, just kicking the can off the end of the chart.

The two billion person limit is something I have seen calculated elsewhere. I was not simply going by Ehrlich's numbers.

Two billion is not sustainable. Until you can by some means recover basically all of the waste stream you do not have a sustainable situation. The only time that's existed is early stone age. (Later stone age is not sustainable--flint gets depleted.)

To predict future population, we need to know what humans will choose to do 30 years from now, and we really don't know. Will there be more or less love making? Will they be using more or less contraceptives?

Every industrialized society has seen it's birth rate crash because children go from being a benefit (labor on the farm) to a cost. The average person does not consider the value of having their 2.1 children worth it. Why should we think people in the rest of the world will not reach the same conclusions?

 

[Loren Pechtel]

we're already seeing mass starvation due to global warming

No, we aren't.

Mass starvation was a twentieth century phenomenon, and hunger on that scale hasn't been seen anywhere for thirty years or more - during which time the population in the last place to see a major famine, Ethiopia, has almost quadrupled.

Disagree.

1) Mass starvation was common before the 20th century, also. It's less common now but still happening.

2) In anything like the modern world mass starvation is the result of governmental policies. If the people in power loot too much the people starve. See North Korea for a prime example. Likewise, if the people in power mess things up to the point that productivity isn't worth it, people starve. (If anything of value gets taken people won't have anything of value--and thus be very inefficient at producing.)

The problem, then and now, that leads directly to large numbers of people suffering from hunger and even starvation, is war.

Not global warming; Not population growth; War.

The key thing that changed at the end of the 1980s, that led to the end of mass starvation, was that the end of the Cold War meant an end to the proxy wars between the Cold War powers that had plagued the third world since the "end" of WWII.

Disagree--the places with famine weren't really part of the proxy war. Mostly, look for Christianity/Islam or Islam/Islam wars. For example, look at South Sudan.

 

[Loren Pechtel]

Its very possible. Especially when one considers other external environmental toxicity (lower sperm counts) not well understood yet. The earth is self correcting as long as there is enough time....but many times a species goes too far to recover and we may be the next example. Throughout earths history extinction has been the norm and there is no reason not to think we will be the exception.

Note that the self-correction applies to the ecosystem as a whole, not to any given component. Normally it is impossible for a species to grow too successful to destroy itself because there will always be fringes. However, humanity is capable of moving resources great distances, there will be no fringe zones to survive a crunch. We are certainly capable of eating ourselves out of existence. It's happened before, it's just we are descended from the survivors and the losers are only noted by the archeologists. (Normally, humans can flee bad places--but when oceans prevent it populations have driven themselves to extinction.)

 

[Loren Pechtel]

IMO Musk has the correct response that we should be looking to Mars and/or the rest of the universe to at least further our overall odds against extinction. Because you can explore and conquer other planets without pissing anyone off who wants to have babies. Exploration and science will work when politics and dictating reproduction can't.

I hate to be the one to break this to you, but no, you won't be taking a trip to Mars to see your grandchildren. See https://dothemath.ucsd.edu/2011/10/why-not-space/ .

Space becomes cheaper as time goes on. In 50 years of going to space the cost per kg has been halved in constant dollars. And then it was halved again. And it will likely be cut to a tenth of that in the next decade.

And even if I had grandchildren I would not expect to go to Mars to see them. There simply is no reason for it--planets are big gravity wells to avoid, not good objectives. Mine planets, live in space.

 

[DrZoidberg]

The thing is that a catastrophic global warming scenario isn't that bad. Humans are extremely adaptible. Yes, the water level is catastrophic. Food production will change. Our living arrangements and living space will be much limitted. But we'll be fine. We've been through a lot worse.

Disagree--the catastrophic scenarios will make much of the world uninhabitable. If it happens fast enough we won't be able to relocate everyone in time.

You've just affirmed my statement. So far nothing we have done has made the world uninhabitable. So why would it this time?

Aren't you just making a modern version of the Cartesian dilemma?