Earth's Carrying Capacity

Thomas Palm wrote:
Rand Simberg wrote in
nk.net:

Thomas Palm wrote:

Multiply the population density of Biosphere II, which could
probably work at that population density, with the area of the
earth, and you get 200 billion.


Biosphere II was never self-sufficient but relied heavily on energy
import, and against the rules had to replace the atmosphere when CO2
levels got too high.

There's nothing wrong with energy import. The earth wouldn't survive
for long without energy import.

If you try to calculate the required "footprint" for humans it
certainly is wrong to exclude the area needed for the powerplant.

No. Like all generalisations, this too is a failure. Solar power satellites
can supply power to a planet without taking local real estate. The rectenna
can be on the roof.

It's like taking the population density of a major city and pretend
you could extend it all over Earth without considering how cities are
dependent on the surrounding countryside for raw materials and waste
disposal.

Recycle. The first n stories will probably be used for greenhouse grow and
industrial occupation, the rest for residence. "Vertical integration' if you
will.

Thomas Palm wrote:
"Ian St. John" wrote in
:

Thomas Palm wrote:
Ian Stirling wrote in
:

In sci.space.policy Gactimus wrote:
How many people can the earth support?

Multiply the population density of Biosphere II, which could
probably work at that population density, with the area of the
earth, and you get 200 billion.

Biosphere II was never self-sufficient but relied heavily on energy
import,

So does the world. But the energy 'imported' from the sun is much
much greater than all of our use put together, so it is not a
limiting factor.

I wasn't talking about the diluted solar energy, but concentrated
energy from powerplants to drive air conditioning etc. Had this
energy been collected from solar cells the area needed for Biosphere
II would have been a lot larger than the buildings themselves. That
Biosphere II was transparent and used photosynthesis for its plants
was quite acceptible.

This is a theoretical construct so I can theoretically use any technology I
want, including off planet power generation and total recycleing within the
building itself. Something on the order of Soylent Green? Trantor doesn't
count since it was supplied by space ships, having no need to maintain a
closed system.

Gactimus wrote:
How many people can the earth support?

A related question: How does this compare to the number of people that
the solar system as a whole can support?

-- Neil

lid (John Savard) wrote in message ...
On 16 Aug 2004 03:30:03 -0700, (Red Walker) wrote, in part:

The U.S. doesn't have a few billion to waste on extravagances like
sustainable agriculture or space-based energy extraction, but they can
always scare up a few billion for a war.

Yes, governments don't have large amounts of money to spend on projects which may
possibly have great benefits... but they have large amounts of money to spend on
efforts which, if not made, have nonsurvival as their clear and obvious result.

I'm not sure what is supposed to be strange about that.

John Savard


Your entire post is probably true in your mental model, but it's false
in my mental model.

For a complete discussion of how differences in mental models relate
to flamewars, please see:

http://en.wikipedia.org/wiki/Flaming
quote
Jay W. Forrester described a phenomenon that often happens in
flamewars whereby participants talk past each other. Each participant
employs a different mental model (i.e. due to fundamental differences
in their assumptions about what a particular word or concept means,
they are actually discussing two different things).
/quote

and

http://en.wikipedia.org/wiki/Semiotics

and

http://en.wikipedia.org/wiki/Counter...Social_Systems


Then, in that context, feel free to consider:

1) I didn't say that it was supposed to be strange.
2) What governments believe to be "clear and obvious" need not be true
or verifiable. Even if wars of survival could be funded, Smedley
Butler and his innumerable students claim that not all wars are
motivated by genuine concerns of survival.

http://www.google.com/search?hl=en&i...=Google+Search

Let W be the set of all wars that could be funded by the U.S. I said,
in effect, that the U.S. can always find money for any war in W.

Let S be the subset of W comprised of wars of survival and let W-S be
the set of wars in W which are not motivated by a genuine concern for
survival.

So I have a mental picture where the set W-S is not the empty set.
You seem to be saying the W-S must be the empty set, if I'm reading
your post as you intend it to be read.

I think you're claiming that W-S is the empty set and I'm claiming
that it's not.

3) Many commentators distinguish between nonsurvival for government
factions, nonsurvival for segments of national populations, and
nonsurvival for nations.

I find that attempting to do logic in metalanguages (such as English)
is inefficient, so perhaps we should try formal semantics or symbolic
logic if we intend to have a meaningful conversation. Conversations
are especially difficult when one attempts to find a common basis of
agreed facts on the world with persons who have radically different
mental models. This is often called "talking past each other."

I think it would be hard to have a meaningful conversation with you,
since you're obviously smart enough to use science as a dialectical
weapon. Faced with such conversations I generally retreat into
logically infallible true statements which most regard as
uninformative about the outside world.


http://home.ecn.ab.ca/~jsavard/index.html

By the way, that's an interesting geometry site. I'm going to
download it and look at it later. I find it difficult to discuss
geometry over the Net, without a whiteboard in front of me, but rest
assured that in meatspace I'll derive many interesting whiteboard
conversations from your web pages.

Thomas Palm wrote:

Ian Stirling wrote in
:

In sci.space.policy Gactimus wrote:

How many people can the earth support?

Multiply the population density of Biosphere II, which could probably
work at that population density, with the area of the earth, and you
get 200 billion.

Biosphere II was never self-sufficient but relied heavily on energy import,
and against the rules had to replace the atmosphere when CO2 levels got too
high.

Added to which, Biosphere was never an ecologically self-sustaining
replicable system - a "growing" world, if you like.

Estimates of the optimal (not maximum) number of human beings the world
should support in a wholly "natural" setting without technological and
cultural support is a mere 1.2 million people (Nature, 2004: New
Scientist, May 2004). This could be extended to around 10 million with
low-impact technology and cultural support and to about 1 billion with
full support. These figures, rather annoyingly, actually match the
pattern of human colonisation prior to the industrial revolution of the
15th and 16th centuries.

John Savard wrote:

That reminds me.

Flax is what linen is made from.

I remember an article, by an agriculture student, in a local student newspaper
which was a rebuttal to the propaganda of how allowing hemp to be grown would
solve the world's problems, because it was a wonder plant.

He noted that flax can do anything hemp can do - except make you high - and do it
better.

Yeah, but "Free the flax!" just isn't as catchy a slogan.

-- M. Ruff

In sci.space.policy Psalm 110 wrote:
Bioshere II failed miserably. They were screaming to get out long
before the two years were up.

It failed in ways that indicate that if it was done properly, and the
bugs worked out (it was a first attempt) you could get more food out
of the system, and still maintain a usable atmosphere.

Biosphere II stunk, literally. Their "ocean" died. It putrified with
stinking rotten slime.

Nobody asked you to "save the world in 25 words of less". The very
first step in problem solving is not to lie to yourself. Check your
data and double-check your sources. You are lying to yourself about
Biosphere II without knowing the real story. In the have dozen times I
corresponded and one time I talked on the phone with the chief design
architect of Biosphere II I am alway trying to politely avoid bringing
up what a MISERABLE FLOP IT WAS.

If you want to learn to solve problems go get a better education.
Somebody who can't tell a stinking failure from a success is not ready
yet.

Biosphere II was a deeply stupid experiment by people who valued the
statement over the science.
The right way to do this kind of thing is not to make hugely complex
systems that you can't hope to accurately analyse, but "feel" right, but
to proceed from simple systems that you can completely analyse up.

Nonetheless, if you built a second one, and only changed the specific
problem that lead to oxygen depletion, the people would not have died
with no additions.

And could do better with a more rational system.

Ian Stirling wrote:

Biosphere II was a deeply stupid experiment by people who valued the
statement over the science.

For example, they were told ahead of time that the unaged concrete would soak
up CO2.

Paul

In sci.space.policy Andrew Nowicki wrote:
wrote:

On 16-Aug-2004, Andrew Nowicki wrote:

Bruce Sundquist has compiled a review of literature about
the Earth's carrying capacity. He believes that the maximum
sustainable population of the Earth is about 1 billion
people. It is determined by topsoil erosion and salination
of irrigated land. http://home.alltel.net/bsundquist1/

Such bases can allow us to calculate a result. But they are pretty
arbitrary. Certainly it isn't hard to come up with ideas that make current
topsoil erosion and salination irrelevant to our production of food.

If you know such ideas and they are feasible,
run to a patent office -- you will become the
most famous and the richest inventor in recorded
history.

Well, for example to make salination irrelevant, you can go to desalinated
water to irrigate.
It's expensive, but technically possible.

As to topsoil erosion, I believe there is a recent development that may
help.
Google for terrace.
It's new and unproved, but it just might work.

Ian Stirling wrote:

Well, for example to make salination irrelevant, you can go to desalinated
water to irrigate.
It's expensive, but technically possible.

You can also periodically flush the farmland with excess water, which
carries away salts.

Paul