What is the population of this sci-fi dystopian future Earth?

Factual Questions
1

This thread reminded me of a short short sci-fi/mystery story taking place in a future Earth of severe overpopulation called “The Sooey Pill,” in which the world is so full of people that the government sanctions suicide after a certain age, but only with a certain pill, conditions are that miserable. Here is what little is revealed about the world:

  1. “Even the Grand Canyon was filled to overflowing with sweating, jostling humanity.” (This is what reminded me of the thread)

  2. Military barracks/dormitory-style living appears to be standard, if not required, for the (vast?) majority of the population, replacing private homes, apartments, and even rooms entirely.

  3. Nutrient pills made from sea life (?) have entirely replaced food, because all land that could be used for farming must be used for living space.

So, given these facts, and assuming that the rest of the world is just as bad, if not worse, than America (where the story takes place), what must the population of this future Earth be, and what is the earliest year in which this story could take place, population-wise?

2

More than the Earth could possibly support without spiraling into a mass extinction, that’s for sure. If all land was filled with housing and concrete and nonproductive dirt, we’d have massive problems related to oxygen production and climate regulation. Not even a pristine ocean, which we also wouldn’t have, could maintain the needed balances.

3

Looking at it mathematically:

The global land area is 57,000,000. mi^2 or 158916 x 10^10 square feet.
The global population is 6 billion.
Assume that people need a minimum of a 2800 cubic feet (20 x 20 x 7) feet of living space in order to live and work etc, with all the associated infrastructure for transport etc. This is a hideous underestimate. Allow a building height to reach 2 miles with 90% usable space. This gives each square foot of the Earth 10560 cubic feet of space.
This allows about 4 people to live on every square foot of Earth or 6,356,640 billion people. Near enough one million times the current population.

More reasonably we would have to say at best we could squeeze in 100, 000 times the current population because a lot of areas won’t take high rises etc.

So we could say about 635,664 billion to cover the Earth like cockroaches.
The question is really unanswerable for any number of reasons.

Firstly the "Nutrient pills made from sea life have entirely replaced food all land that could be used for farming must be used for living space " criterion. it doesn’t make sense. It would be more efficient to put the people in the sea, and se the land to grow food hydroponically. Or else place hydroponic farms on floating platforms.

That aside with multi-level hydroponic farms and nuclear power we have the ability to produce vast amounts of food anywhere, including in orbit. With this sort of technology there will never be a situation were all the available area for growing conventional food is taken up with people. It’s simply impossible because the population would literally exceed physical carrying capacity before that happened. Basically it takes less room to feed a man than for that man to live and work.

Depends on what you mean. In the real world it can never take place. The human population will peak at about 9 billion and then decline.

If you mean theoretically possible with no reference to reality, then assuming a constant doubling time of 20 years, which is about maximal for humans, we get an answer of around 150 years time.

[qu
[/quote]
ote] . If all land was filled with housing and concrete and non productive dirt, we’d have massive problems related to oxygen production
[/quote]

No we wouldn’t. If we removed all the plants on the planet we would decrease oxygen levels by about 1%. Not even enough to notice, much less a massive oxygen problem.

4

Yes, we WOULD have an oxygen problem. Our atmosphere is not static, but dynamic. Every animal that breathes, all organic matter that decays, everything that burns removes oxygen from the air and dumps in carbon dioxide. Every time a plant photosynthesisizes it removes carbon dioxide from the atmosphere and dumps in oxygen. Without plants constantly adding oxygen to the atmosphere we would have a nitrogen, methane and CO2 atmosphere pretty quickly. It might take a few months or a few years, but pretty soon there would be almost no free O2.

Of course, feeding hundreds of billions of people with seafood is ludicrous, oceans are typically less productive than land. Even with our current global population and only a small part of our global food supply coming from seafood we are rapidly overfishing most fish stocks. Our current level of fish harvest is unsustainable, and we’ll all be eating less fish in the future even if the global population stays under 10 billion.

5

Another problem would be heat generation. Every person, and all the machines required to keep them alive, would produce waste heat. The waste heat of 6 quintillion people would be more than enough to fry the earth unless it was moved into a neptune-like orbit.

6

Cite.

That is simply not true by any stretch.

I challenge you to find any references at all to support that assertion. Before you bother though I suggest you read this thread and the links therein.

http://boards.straightdope.com/sdmb/showthread.php?threadid=189748

How did this myth that plants are responsible for maintaining the oxygen in our atmosphere become so ubiquitous?

7

Yes, but they don’t have to be land plants. Tiny algae in the top few millimetres of the oceans could do the job fine. In fact i think they do carry out more photosynthesis than land plants even now.

Regards,
Agback

8

Try <http://www.ucmp.berkeley.edu/bacteria/cyanointro.html>. “The oxygen atmosphere that we depend on was generated by numerous cyanobacteria during the Archaean and Proterozoic Eras.”

Or <http://www.ecoworld.org/Air/EcoWorld_Air_Home.cfm> “All the oxygen in Earth’s atmosphere is believed to have come from photosynthesis.” “Without plants, from alga to the trees in the rainforests, there is no photosynthesis. Without photosynthesis, the oxygen in the atmosphere would be gone in a few thousand years.”

Regards,
Agback

9

Oops! I muffed the coding for that second link.

<http://www.ecoworld.org/Air/EcoWorld_Air_Home.cfm>

Regards,
Agback

10

G’day

Something weird is going on when I post URLs. Sorry about that. Without any attempt at coding, the links are:

http://www.ucmp.berkeley.edu/bacteria/cyanointro.html

http://www.ecoworld.org/Air/EcoWorld_Air_Home.cfm

Regards,
Agback

11

I hardly think that 'Ecoworld’counts as a reliable reference.

Ecoworld is, according to their homepage, " an internet publishing company’ whose CEO is Ed ‘Redwood’ Ring. Aside from being 'Providers of earth-friendly products and services " and a plug for advertising sales precious little information is given.

This appears to be a environmentalist ‘save the tree’ organisation with no absolutely no references for their opinions. Given that what they say flat out contradicts a man who stands as probably the world authority of the oxygen biogeochemical cycle and articles printed in peer reviewed journals I hardly think we can credit what is on that site, do you?

The Berkely article doesn’t even seem to mention plants at all, much less what would happen without plants. As such I fail to see its relevance.

Care to try again? Or do you simply believe what you read on website despite it contradicting scientific orthodoxy?

12

It is true that the oxygen in the air is of biogenic origin, but it is not true that you could convert it to carbon dioxide by metabolising all the available carbon in the biosphere.
Most of the corresponding carbon is inaccessible, in sedimentary and metamorphic rocks.

Having said that, if you really wanted to cover the earth in concrete, or other rock derived building materials, and support 600 trillion people you could do it, but it would not be easy.
First of all the biomass of humanity would be ~4 x 10[sup]13[/sup] tonnes, ten times the current biomass of earth;
it would be necessary to convert all the coal reserves and some carbon rich rock reserves to human biomass to achieve this figure, then the question of food arises.
With an advanced recycling technology converting human waste to food it could perhaps be possible to support this mass of humanity with ten times the mass of autotrophic food production, which would need the entire surface of the earth to be covered in genetically tailored algae, 10[sup]14[/sup] tonnes of it,
or 1 tonne of biomass per 5 square metres of surface area.

this is a bit tight… but at least such a ferocious level of autotrophy should produce enough oxygen to support the human population , who would be living in a worldwide city underneath the worldwide algae tanks.

All this recycling of food and other activity would require a lot of energy, and would produce a lot of waste heat; the sun produces plenty of energy, and more could be collected and beamed to earth if necessary; but getting rid of the waste heat might be a problem-
you might have to dedicate a large area of the earth’s surface to cooling radiators to dissipate the waste heat during the night time, and some of the food production would need to be moved off planet.

In short, it could be done, but it would need such high technology to maintain that a million other more comfortable ways of living would be available.

SF worldbuilding at
http://www.orionsarm.com/main.html

13

I think you’re referring to “Soylent Green”. And the person further down who said the population had to be more than the carrying capacity is right - toward the end of the movie, at least (I haven’t actually read the original book) the protagonist discovers that “Soylent Green” (the favorite “food” handed out to the masses, given I believe on Tuesdays?) DOES NOT come from marine life, but from recycled human bodies - “Soylent Green is made of people!”.

Clearly untenable in the long run.

It was quite a filme noire, and I suspect the book was even worse…

Dan Abarbanel

14

“Soylent Green is made of people!”.

That was in the film, but not the book-
the book was about a near future, relatively overpopulated world, but the story was a fairly realistic detective story with almost no SF elements…
the population scenario Harrison depicts in the book, ‘Make Room, Make Room’ has turned out to be wide of the mark; nevertheless it is well written, as most of his stories are.

SF worldbuilding at
http://www.orionsarm.com/main.html

15

Well, I admitted that I hadn’t read the original book :frowning:

I stand corrected.

Dan Abarbanel

16

An interesting plot feature in the novel is that shortly after his roommate (The E.G. Robinson character) dies, a family of 10 shows up at his doorstep with a so-called “squat order”, a document entitling the bearer to move in where any vacancy occurred.

Despite that, neither the book nor the movie were as bad as the description in the OP. It seemed that a lot of people still had rooms to live in.

17

For the record, the story the OP was talking about was published in Ellery Queen’s, which my parents subscribed to. I remember reading it as a teenager. A bit of reasearch proves it to have been “The Sooey Pill”, by Elaine Slater, published in the June, 1969 edition:

http://members.tripod.com/~rimes12/eqmmR.html

18

OK, yes, perhaps if we burned all the biomass in the world we wouldn’t use up all th oxygen in our atmosphere. But that is because over the billions of years a lot of carbon has left the biosphere and became fixed into coal, oil, carbonate rocks, etc. Plants fix carbon and excrete oxygen. And yes, the plants do indeed respire also, and take up oxygen and excrete CO2 when they use the sugars they have created through photosynthesis.

But, plants produce more fixed carbon than they respire. This can be seen in any forest…when a tree dies a huge mass of carbon has been fixed. The plant itself doesn’t use that fixed carbon for energy. The carbon in the wood just sits there until it is eaten by fungi or bacteria, or it is burned, or it is buried and sequestered. Over the billions of years of life on earth a lot of carbon has been sequestered. Which means a lot of oxygen has been dumped into the atmosphere.

O2 is a highly unstable molecule, in a very high energy state. Every so often the oxygen in our atmosphere will spontaneously combine with other molecules, releasing a tremendous amount of energy. This could be hydrogen, metals, or–most typically–carbon compounds. If this happens to the carbon compounds that make up your house it can be very upsetting.

Our atmosphere is NOT in an equilibrium state. The high levels of O2 in our atmosphere are maintained by plant life. I’m not a trained geologist or chemist, so I have no idea how quickly the O2 levels in our atmosphere would decline if photosynthesis suddenly stopped. But every molecule of O2 in our atmosphere was produced by a living plant via photosynthesis.

19

Indeed, oxygen is a very reactive element- but practically everything it can react with has already reacted with it.
Once you allowed the biomass of the earth to oxidise there would not be much left to combine with the free oxygen- it might drop from 20% of the atmosphere to between 19%-17% depending on which estimate you believe.

Actually if that were to happen the Earth’s atmosphere would be very different- hot and probably unbreathable to humans-
so i emphatically do not recommend this couse of action;
but there would still be plenty of oxygen around, and it wouldn’t be going anywhere in a hurry.

SF worldbuilding at
http://www.orionsarm.com/main.html

20

Perhaps, but as I said the biomass of the earth is only part of the sequestered carbon. And there are other things than carbon to react with the oxygen. Over time many of the minerals in the earth’s crust will change to a more oxidized state. Again, I’m not a chemist or a geologist so I have no idea how long this would take.