The US currently has a population of approx 300 million (very rounded). To how many could that population safely grow before the US has to import food?
Well we already import some food, and if you’d like bananas, chocolate, or coffee for example, I think you’re stuck with importing. We might grow some small quantities here, but I don’t think it’s much. But we do export a lot. Around 50 metric tons to China, 30 to Mexico and 10 to Canada. Those countries are also the three we import the most from I believe at 1 10 and 20 metric tons.
There is no simple answer to this without identifying the kind of diet expectations the population expects. Obviously, the United States is an enormous breadbasket for wheat, soya, and corn production, and also produces a lot of rice and pulses, much of which is either used for feedstock into livestock or food synthesis using the oils and other products, or is exported to less productive nations.
However, there are two significant issues to consider: palm oil and sustainable water. Palm oil, extracted from the mesocarp of oil palms, finds its way into nearly all consumable products; processed foods, toiletries and cosmetics, et cetera. It is a nearly ideal oil for a lot of consumer products because of its shelf stability at room or even somewhat elevated temperatures and high yields, but the oil palms require large tracts of subtropical or tropical rainforest land (and is driving deforestation in Indonesia, Sri Lanka, the Amazon, and elsewhere where it can be grown). It does not represent a large fraction of the caloric content of processed foods (which is dominated by high fructose corn syrup) but it is a key ingredient that would have to be replaced by hydrogenated oils that have been (justifiably) savaged.
The other is that a good amount of our food production, particularly grains in the American Midwest, citrus in the Southwest, and the California Central Valley, uses unsustainable supplies of groundwater such as the Ogallala Aquifer, the Colorado and Rio Grande river systems, and the Central Valley Water Project. The Ogallala is a fossil water reservoir that is not being refilled at anything close to replenishment rates; the Colorado and Rio Grande are being used at excess of what those systems can sustain, resulting in downstream contamination and silting, and the impacts on the Sacramento-San Joquain delta are obvious to anyone following California’s agricultural industry. If predictions of more severe climate conditions and extreme weather due to global climate change come to pass (as they already appear to be) droughts, floods and exhaustion/subsidence of fossil water sources my overwhelm agricultural systems even if high efficiency irrigation systems such as drip irrigation is implemented, and food production may fall.
The US can still produce a bounty of food in terms of calories–its current food production potential couple provide the baseline calorie requirements for the more than seven billion people currently alive on the planet–but we’d basically be eating carbohydrate and processed oil junk food.
Stranger
I’m wondering if the food supply is the limiting factor. Might the clean water supply turn out to be more important in determining maximum population that can be supported?
Crops require water, so the two questions are one and the same.
People need clean water - crops are happy to use used water.
The good news is that agricultural water is used in horribly inefficient ways, which means we just have to stop doing that.
And if everyone’s happy with 95% of their diet being wheat, corn and soybeans then we can deliver an astounding amount of raw calories and essential amino acids. And we can add in some very cheap synthetic vitamins to avert the deficiency diseases that used to plague people who ate almost nothing but one or two staple crops, and we’re golden. Bread and fortified soybean cakes for everyone! Maybe some circuses while we’re at it?
At one billion I don’t think we would be overly crunched. Areas of the country currently sparsely populated would need to become more like Los Angeles and New York I imagine.
If we had to house another 700 million people we wouldn’t be building new megalopolises in the middle of Nebraska, we’d increase density in areas that are already dense. If you think LA traffic is bad now, wait for the traffic in San Los Diego. Over on the East Coast welcome to Mega City One, stretching from Boston to Norfolk. Oh, and since most of Florida is an intertidal zone we’re going to have to relocate all of them as well.
I think you meant million metric tons in all cases.
That I did, sorry.
No specific answer, but a good chunk of the food produced right now is never even consumed.
I see “push lists” from manufacturers all the time in my line of work.
EVERY single week, a certain poultry company produces over one million pounds of seconds, basically miscut chicken, not pretty enough for #1 retail.
If people, or stores (whichever one is refusing seconds, doesn’t matter much for this thought) start consuming secondary products, i think the population could double with no need to increase food supply.
Does this assume we are growing the food on the arable land we have or can we posit use of multilevel farms driven by nuclear energy? Because such farms are something completely achievable with existing technology. Basically they are just warehouses that have multiple stories, and inside are plants, probably grown in hydroponics. Ideally the plants are genetically modified for these conditions, and they are exposed to light 24x7 for rapid growth.
Light obviously comes from LEDs and the energy source obviously is nuclear.
Then the people live in multistory towers in apartments. And to avoid the inefficiency of converting plants to meat - you lose 3 to 7 times the nutrients - all the ‘meat’ is various forms of meat substitute.
I’d say we can do at least 10 billion, easily, doing just this. And if we had technological growth remotely corresponding to a society where of that 10 billion, say 10% are scientists and engineers (we could mass educate using inexpensive online courses), I would assume that tech advances to allow an even vaster population could be made. Worldwide, I think if you covered the planet in 100 story buildings, you could support AT LEAST 1 trillion people. Probably more than that.
Now, there are problems. People don’t like to be in close proximity to one another like this. An effective society would have to make sound deadening in the walls of these massive arcologies mandatory.
Yeah, I said arcology. In a world like this, it makes total sense to just have workplaces (after all, most jobs can be done either remotely or in small collaborative teams in offices) in the same building as the apartments. Might as well put the primary school and the day cares in the same building, after all, at least 50,000 people would be residents of a single arcology tower. (the towers would be a structure similar to the world trade center towers, using a similar design to maximize floor space). Might as well have primary care doctors office’s in the same towers as well. Might as well have the basic supplies sold from stores in the same tower. People would still leave their home towers, but it’s so much more efficient to make it where they don’t have to very often.
It makes sense to have automated monitoring of every resident’s location. Be fairly easy to solve any crime that way, and to deter most crime through swift and immediate punishment. (there’s no reason for them to become lawless like in Judge Dred - that universe is a complete failure of government)
No reason for anyone to have a gun. The cops would be 2 minutes away.
That universe is a satire.
I have always wondered this for Canada. Enormous country with a population of only 36 million. Less than California alone.
I guess the population growth would have to be very gradual.
The United States with the population’s density of India @ 368 PKM*: 3.4 Billion people
If only CONUS is used: 2.9 Billion.
The CONSUS with South Korea levels of density: @ 487 PKM = approximatkey 3.9 Billion
CONSUS with Bangladesh levels of density @ 967 PKM:= 7.8 billion.
China is slightly bigger than CONSUS; has about 4 times the population, yet has about @ 144 PKM.
- India is actually not particularly densely populated by world standards; it about middle; level, slightly above the W European average.
Large parts of Canada are uninhabitable.
This article comparing population densities may be of interest. It shows that compared to the rest of the world, almost all of India is very heavily populated. Unfortunately, it doesn’t include Europe as a whole, but does include a couple of European countries.
Yeah, that looks wrong.
It includes Pakistani Administered parts of Kashmir as India. It has a population denity slightly that of the 2-4 times the world. The place is a frozen tundra, most heavily glaciated region outside the poles.
Yes, get beyond a certain point and the growing season is non-existent. Find a population map of Canada, and most of the uninhabited areas are uninhabited precisely because between rocks and climate, it cannot be farmed. It does not help that the biggest cities sit on prime agricultural land. But… the same is true of India and China. most of western China is desert (think, Gobi) or mountains. India not so much, but the northern/western area is approaching desert outside of the main river basin, and the central area IIRC is rough highlands not fertile plains. The huge populations of both are concentrated in a fraction of the area.
The USA is quickly exhausting its western aquifers, all the central-pivot irrigation neat the foothills of the Rockies would soon run out of water. however, as pointed out above, there’s a huge amount of food waste in the system. Plus, a lot of food is grown to feed animals. A billion-person USA would eat a lot less meat.
However, population is levelling off if this is what you are wondering about. Most western countries are on a downward population spiral, if not for immigration. (Japan and Russia are apparently the worst). Even China is starting to worry about two or more generations of single-child policy compounded by late-in-life marriages. If you thought having a child nowadays was too expensive, you are right - and billions of couples in the first world have reached the same conclusion.
I just (accidentally) started a post where I was wondering about the capacity for the U.S. to hold people. When you drive across the country, you encounter miles and miles of seemingly undeveloped land. These numbers are interesting; if we were “full”, I can easily imagine several billion Americans where wide open pastures used to be.