Carrying capacity by tech level

[parmasson]

Carrying capacity by tech level.
At what point does a population become too large to overwhelm a planet’s ability to feed its own population by tech level in game terms?
Could an earth size planet support 50 billion people at TL-12
Using:
Vat growing technology
Hydroponics
Ocean farming
Of course the lifestyle of those people would have an impact on the ability of the environment and such.

Could a table like the one found in LLB2 for jump drive capability be constructed to give an idea of a planet’s carrying capacity?

 

[mike wightman]

How many people could be fed by world wide food production today?
IIRC there is more than enough food produced world wide to feed more than the Earth's current population.

How many could be fed with today's technology if every country used the most efficient, high tech farming/food production methods?

There must be data on food production through history, perhaps this could be used to extrapolate from?

 

[parmasson]

OK using figures from medieval England at the time of the Black Death the countryside was rather crowded with about 80 people per square mile. Us that as a base figure and multiply by available square miles on earth subtracting some for mountains and stuff and the figure I get is an amazing 3-4 billion at TL-2. Keep in mind this is a just a rule of thumb for game purposes. I will have to work on other tech levels later today.

 

[parmasson]

About 40 million people lived in England during World War II and although rationing was introduced basic foodstuffs could still be provided by domestic sources just barely.

That is very roughly 790 people per square mile @ TL6 = 40-45 billion maximum world wide population. That doesn’t sound right. I have to go back and look at it again. At this rate the planet will be able to support 60+ billion at TL-9 and at TL-12 close to 100 billion. That would mean that only vacuum worlds and the like would need to import food.

 

[rhoneycutt]

I think it takes energy (sunlight ) and water to grow foodplants. A large portion of the world's surface might not have the required amounts to make things easily computed. It also means that food sources that are based on photosynthesis that humans have evolved to eat, will have outputs that are roughly proportional to incident radiation. Using photosynthesis as a model, it should be easy to figure out how much water is needed for each Kg of food(plants) produced. Animal food production should be roughly 10% of the plants they are allowed to eat. Again...water is required. I assume that nutrients would be plentiful, else food production would drop lower still.

Food is on the trade tables for a reason.

 

[mike wightman]

Unlimited fusion power allows you to grow plants using "light bulbs" for sunlight.
Your fields can now be stacked one on top of the other like the floors in a multi-storey car park.
These multi-storey farms could be built underwater, underground, inside asteroids etc.

 

[Madarin Dude]

This is a personal observation. Here in China the worlds most populus nation. (by far nto the most desly populated) people waste mor efood than I have seen anywhere else and a large portion of the country is mountains and desert so only maby one half is actually capable of supporting farms.

That said both britain and China have very fertile land with a lot of rainfall. Once the power for grow lights is so cheap it does nto matter much then you can really multiply the capacity.

 

[parmasson]

Here is what I have so far. May or may not be useful to you world builders but it is fun to think about it.
Still thinking about the hard numbers. It looks like it is a geometric curve getting steeper as the tech level increases and then leveling off somewhere around tech 13-14.

TL-1 Rudimentary knowledge leads to crop rotation and basic irrigation schemes
80 pr sq mi

TL-2
Improved crop rotation schemes and more complex irrigation systems make large scale plantations possible.

TL-3
New innovations in farming policy and new scientific knowledge about plant and livestock breeding ensure increased yields and fewer incidence of famine.

TL-4
The introduction mechanized seed drills, and harvest equipment allows for more efficient harvests and higher yields, and fewer total crop failures.

TL-5
Fertilizers, and self powered tractors greatly improve harvests.

Tl-6 790 per sq mile
Selective breeding, irrigation and scientific planting ensure high yields.

TL-7
High yield fertilizers, intense irrigation and mechanization doubles harvests

TL-8
Improvements in automation plus the first genetically modified seed and livestock appear making marginal land productive. Hydroponics and ocean farming become possible. Satellite monitoring and improved soil science increase yields. Impressive irrigation schemes can reclaim desert land for food production.

Tl-9
More automation and improvements in genetic engineering make crops nearly disease and drought proof. Robots begin to take on duties once filled by sophonts.
Thanks to advanced water reclamation systems massive conversion of infertile land and highly advanced fertilizers create farms where once only sand and rocks existed.

TL-10
Massive scale hydroponics powered by fusion and tended by robots transform the nature of agriculture. Vat grown meat products are introduced moving production from the field into the factory. Highly advanced seed, lighting and irrigation allow for 24/7 growing and fast automated harvesting. Colonies on vacuum world now have sufficient technology to produce foodstuffs in quantities to allow small surpluses.

TL-11
With improvements in gravitics and materials technology multi-level hydroponic farms become economical turning a single farm into an agricultural factory capable of producing truly astounding amounts of food on a year round basis. Computer controls, robots and automated monitoring make agriculture automated.

TL-12
Improvements in previous technologies lower costs and increase yields. If practiced conventional soil based agriculture becomes a snap. Ultra-high yields, superior seed and engineered livestock greatly reduce the risks and environmental impact. The need for fertilizers nearly disappears and does the need for irrigation as crops can be custom tailored for their environment.

TL-13
Decreased costs plus improvements in computer technology allows for onsite seed engineering thanks to plug and play bio-engineering systems. Multi level farms can become sky scraper height and maintain their economy. Due to very low prices the size of the establishments become massive covering at least hundreds of square miles. Vat growing becomes extremely efficient and nearly indistinguishable from traditional production.
Soil based agriculture reaches something of a plateau as ultra adaptable crops and robotic automation allow for yields that are unimaginable at lower tech levels.
TL-14
TL-15

 

[rhoneycutt]

fusion power and light bulbs?

a huge increase in the initial cost of infrastructure and cost of maintaining infrastructure....at what point would it be cheaper to import, then?

this makes any arguments degenerate into macro-economics......hmmmm..solving that would solve so many problems. Military budgets, for example.

fusion power solves all problems also implies that on marginal worlds, large populations cannot exist until they have large fusion power ( to match earth....1300watt/m^3...of course food production actually uses far less than that. )

I merely mentioned limiting factors that must be considered and to explain why 'X pop per area multiplied by area of world wouldn't work )

 

[Fritz_Brown]

Originally posted by Parmasson:
TL-8
[...] plus the first genetically modified seed and livestock appear ....

Well, actually, the first genetically modified seed and livestock appear sometime around the Bronze Age, IIRC.

I think you mean the "first direct genetic manipulation of seed and livestock appear".

 

[parmasson]

Originally posted by Parmasson:
TL-8
[...] plus the first genetically modified seed and livestock appear ....

Well, actually, the first genetically modified seed and livestock appear sometime around the Bronze Age, IIRC. [Smirk] I think you mean the "first direct genetic manipulation of seed and livestock appear".

Yeah, I am talking about laboratory manipulation of genes.

This list is just suggestive of what is possible not of how things are actually done.

For example.
B-866846-C if I remember my UWP right would have no need for stackable farms.
Depending on the economy they might be a net exporter of food.

However if you had a vacuum world with the same population digit you might just consider making the investment as you don’t want to be totally dependant on imports for food.

fusion power solves all problems also implies that on marginal worlds, large populations cannot exist until they have large fusion power ( to match earth....1300watt/m^3...of course food production actually uses far less than that. )

I merely mentioned limiting factors that must be considered and to explain why 'X pop per area multiplied by area of world wouldn't work)

I see your point but I am not looking for an exact equation that would define the conditions of a Malthusian Crisis I am just looking for a rule of thumb guide that might give some idea of when a world was over populated to the extend that it needs to import food for plot reasons the players would understand.

At first it looked like an earth sized world @ TL-12 with 40 billion people could not produce its own food. Now it looks like it may be able to. Granted the costs might be a bit higher with supplemental imports thrown in but they will be able to.

If you want to talk about the effects of Virus and that sort of thing it will make Ethiopia and Sudan look good.

 

[Straybow]

As of late 20th century, Earth had 6.2 M mi² of arable land in use. Backward farming techniques support ~1000/mi², the most advanced support ~4000/mi². Post-harvest waste accounts for 50% of food produced. Also, much grain is used as fodder, which greatly decreases net number of people supported.

Without improving post-harvest loss or decreasing meat in diets Earth can support ~24 billion using 20th century tech without increasing arable land in use.

Reducing post-harvest loss by half would raise net productivity by half. Eliminating fodder would roughly double the number of people supported (raising livestock only on land unsuited for other crops and as part of crop rotation), but meat in diet would decrease significantly. Thus ~72 billion could hypothetically be supported by Earth's present arable land use with 20th century technology (but not with existing political chaos).

Throw in expanding arable land use and various hydroponic schemes and the numbers go off the proverbial charts. We currently have about 5-6 million mi² devoted to human occupation. If we were to raise livestock in our yards and put hydroponics on our roofs we could double the land area in agricultural use without doubling the total land in use (using very round numbers).

That's just for single-story, natural light hydroponics. Then there is seaweed and other marine mass agriculture products we haven't considered, yet would be doable at 20th/21st cen tech level. Throw in meatvats, algae-based synthetics, etc and there is no reason for any high-tech planet to import food staples.

Eliminating open arable land entirely does little to inhibit intensive hydroculture. The same level of technology that makes lifting food to orbit and shipping across parsecs economical will make home-grown food economical.

A well-ordered high-tech society on an Earth-like planet could support hundreds of billions.

 

[rhoneycutt]

Which means little in Traveller, as there are so few 'earth-like' worlds around. What does this mean to the common small marginal ( airless rockballs ) worlds with little air and water? Those, which seem to be more common in the OTU, would not be able to achieve these sorts of numbers. They would have to import. If it is cheaper to import than grow their own....they'll import anyways.

 

[parmasson]

By Shere Khan
Which means little in Traveller, as there are so few 'earth-like' worlds around. What does this mean to the common small marginal ( airless rockballs ) worlds with little air and water?

I see your point but I disagree because of . . .

Big ship vs little ship
In the OTU big ship universe shipping costs might be low enough to make it work. A 750kt freighter can haul quite a bit. In a Proto-Traveller like small ship universe the costs go way up.

Productivity increases
Even if Straybow’s figures are for an earth-like world I think that we can assume that intensive advanced (TL-10) greenhouse agriculture could generate productivity levels at least equivalent to TL-8 open air production. Stack four, 1 square mile farms underground at TL-12 and you should be able to support at least 40,0050,000 people very comfortably. Growing 24/7/365 plus four tech levels of advancement must produce some astounding results.

Security
If you have a larger population 100,000+ you don’t want to be constantly at the mercy of someone else for your very survival with something as basic as food.

 

[Jeff M. Hopper]

What about manufacturing food instead of growing it?

Synthetic food production should be doable with enough available power. I'm not talking 'Soylent Green is people', but more like the protocarb that is described in Jerry Pournelle's CoDominion stories (IIRC, it is made from processed oil that is cooked into higher level proteins and carbohydrates). With synthetic food manufacture, a single carbonaceous chondrite asteroid could provide the raw material to feed a high-pop planet (another job for belters right there).

 

[parmasson]

I had not even heard of that! What tech level do you think it becomes available? Does that mean I can “construct” green beans or is it something more like the Food Flavored Nutrient Product ™?

 

[rhoneycutt]

big ship vs. little ship
thats a matter of preferance, of course, but if there is any amount of trade between worlds beyond small trinkets, there will be big ships for the same reason we have supertankers to carry oil instead of many smaller ships...economy of scale. I see no reason to artificially limit the volume that a ship may be except ,perhaps, by limiting jump drive capabities. ( rating jumps by mass instead of volume would be neat...one unit of j-drives gives 500tonnes of 'j-thrust'? )

productivity increases
thats just speculation as there is a physical limit to how much edible product can be grown in a limited space. I'd think it'd also preclude any variety of food...no beef or chicken....just processed-pond-scum-algea-sludge. I"ll use the model given in canon World Tamer's Handbook instead.

Security
a world with such a small population will be dependant on outside resources of some king anyways, whether its food or high-tech parts from worlds that have enough people to support the infrastructure of high technology

think of how food is produced and supplied to new york city...and to smaller towns too. I think small ships are analogous to over-the-road tractor-trailers in this case. And big ships are like container ships and ocean cargo carriers.

 

[Uncle Bob]

What about growing food in O'Neil habitats?
Cheaper than importing, but more expensive than factory produced "food".

 

[mike wightman]

And no need to have just one deck, you could have several stacked on top of each other.

Asteroids provide the raw elements needed, solar or fusion powered factories produce the fertilizers, water, and "sunlight".

Use robots for labour...

 

[Jeff M. Hopper]

Originally posted by Parmasson:
I had not even heard of that! What tech level do you think it becomes available? Does that mean I can “construct” green beans or is it something more like the Food Flavored Nutrient Product ™?

Its more like the Food Flavored Nutrient Product (How'd you get that TM thingie to work?). It'd take more energy, but you could start with straight volatiles (methane, ammonia, water, carbon dioxide) and reform them into simple sugars (glucose, fructose, maltose) and then on up into proteins and carbohydrates. It'd definitely take some power, but you have fusion or a nearby star to provide that.