Based on the assumption that a nation’s theoretical population is proportional to its arable land. From the CIA World Factbook, I compared the populations of India and China to their arable land and found that China has 884 people per sq. kilometer of arable land while India has 668 people. Using the higher Chinese figure, then the theoretical populations of the largest nations would be as follows:
United States: 1.75 million sq. km arable = 1.5 billion people
India: 1.62 million sq. km arable = 1.4 billion people
China: 1.44 million sq. km arable = 1.3 billion people
Russia: 1.24 million sq. km arable = 1.1 billion people
European Union: No Data
Australia: 0.50 million sq. km arable = 0.4 billion people
Canada: 0.45 million sq. km arable = 0.4 billion people
Is this analysis valid, or am I missing something?
Why do you assume population is correlated closely with the amount of arable land? By the same analysis, Switzerland has 1,740 people per sq. km of arable land, and Japan has 2,766. By Japanese standards, the US should be able to support 4.8 billion people.
Besides what **Colibri **pointed out, you assumed that Chinese agriculture is as efficient (yield/acre) as US agriculture, and that agricultural efficiencies can’t be further improved.
The biggest problem is that all arable land is not equally. While all arable alnd can be used to grow food it varies greatly in fertility, rainfall, usable sunlight (PAR), climate, soil properties, slope and numerous other factors that all affect how much and what type of actual food can be produced. To demonstrate this let’s consider two different plots.
Plot A is a deep, highly fertile soil with moderate slope in the tropics with an adjacent permanent watercourse and receiving 2000mm of rain annually, spread evenly throughout the year and with an annual deviation of 5%.
Plot B is a plot with a steep slope, with a skeletal phosphorous and nitrogen deficient acid soil in a temperate region with no available water and receiving 800mm of rain annually, 85% of which falls autumn and with an annual deviation of 60%.
Those are both considered arable land, yet plot A would produce 100 times more calories than plot B over a 10 year timeframe. It is simply not valid to assume that an area’s carrying capacity is proportional to the areas of arable land.
Added to that you have an countless complicating factors like:
*patchiness and “dead space”
the fact that a nations often can’t sustain modern agricultural practices like fertilisation and irrigation practices without the income derived from agricultural exports
*the fact that sustainability declines as you approach subsistence levels
The amount of arable land will allow you to estimate maximum carrying capacity with a margin of error of about 90%. IOW the actual carrying capacity might be 10 times higher or lower than your estimate. In some cases your figures are probably close to the mark (eg India). In other cases it seems improbably optimistic (Canada). In some cases it’s clearly ridiculous (Australia).
Like I said, it’s too complex to calculate easily. The suggestion isn’t immediately ridiculous, but it would require a lot of effort to work out what the actual internal carrying capacity of the US is. A lot of the area considered arable land is along way from being prime land (eg the Great Plains) and most of the area is cool temperate so only one growing season is possible per year. That will drive the potential down a long way compared to more tropical and warm temperate climates like India or southern China.
Off the top of my head I would say that the US could never equal China or India, but that’s a semi-educated guess at best.
Look, I pasted together this set of agricultural maps from Britannica Online. If you focus on the light green areas labeled “Crops and Livestock”, it looks like the U.S. has much more than either China or India, and about the same as Europe. Add to that our orange “Ranching and grazing” area and I would say we have the most overall farmland of everyone. These maps are to scale.
Those Britannica maps appear to be current primary commercial land use, not potential land use. If that is the case they are fairly meaningless in terms of carryting capacity.
Even if this were not the case, how does it change anything that I said in my first post? I will repeat, all “Crops and Livestock” land can be used to produce crops, that does not mean that all “Crops and Livestock” land is equivalent. There are far too many other factors to make such a comparison useful way of predicting carrying capacity.
On of the more striking differences you can see from those maps is that almost all of India’s and large swathes of China’s cropland is tropical or subtropical permitting year round cultivation. In contrast the US has no tropical cropland and only small areas of subtropical land in the south-east. You can not simply ignore such differences and expect to produce any meaningful results.
At the very least you need to incoporate annual precipitation, mean temperature wettest quarter, A horizon depth and nutrient status, evaporative demand and water harvesting capacity into your model before it will tell you anything at all.
One important consideration is that countries like India and China can support a large population because they import food from other nations like the United States. If the United States had the same population level as China or India, it in turn would have to import food from some other country.
That’s not really accurate. Both India and China have been net food exporters for several years now.
It’s hard to get solid figures on whether a country is a net calorific food exporter as opposed to monetary exporter, but best figures I’ve seen suggest that India is almost certainly a net calorie exporter, and China probably is.
The worst case scenario is both countries are essentially breaking even, and given the economic capability of utilising more fertiliser, more irrigation and better agricultural science they would certainly be clear net calorie exporters.
So it is not true that India and China can only sustain those populations because they import food. It may be they can only sustain those populations through economic inputs from other sectors, but that isn’t the same thing at all.
It is probably true that the US would need to import food if it reached the same population level. But that’s been my point all along.There is far more to being self-sufficient than simply area of arable land.
Well, maybe I’m being influenced too much by Jared Diamond. It appears to me that China and the U.S. are at approximately equal lattitudes, and you know what he says about that… Anyway, that’s what got me thinking about this subject. Not that there arn’t enough threads about that guy already!
To sum up points that have already been made, there are at least two critical flaws in your reasoning:
As Blake says, the area of arable land alone does not translate to productivity of food. A hectare of rice paddy is astronomically more productive than a hectare of semi-desert ranch land. You would really need to use figures for potential productivity of all arable land, rather than simple area. You would also have to allow for the fact that productivity can be enormously increased by artificial means such as irrigation and fertilizer.
Even at that, although there may have been some correlation between population and land productivity under pre-industrial conditions, all that goes out the window once you have substantial international trade in food. Net food exporters are supporting a higher total population than their own internal one, since people in other countries are substisting on food produced there. On the other hand, there are net food importers that are able to support a population much higher than their arable land would be able to because of trade, manufacturing, or the export of non-agricultural products. To take a couple of extreme examples, Bahrain is able to support 36,810 people per sq. km due to its oil exports, and Singapore 388,221 due to trade and manufacturing.
It’s simply a amtter of observing that the United States uses land in very wasteful ways. From a physical perspective, we could cram huge numbers of people into extremely small space, and open up more landing for farming. (Whether that’s economically and socially feasible is, of course, a different question.) But if we were to bulldoze every McMansion and sprawling ranch home and force the inhabitants to live in small high-rise apartments, we’d suddenly have millions of acres land to farm. Further, we have tens of millions of acres sets aside as parks, forests, military bases (almost the entire state of Nevada belongs to the military), or simply lying empty because it can’t be farmed profitably. Further still, tens of millions of acres go to crops such as tobacco that don’t contribute to the food supply. Considering all those factors, it would certainly be possible for the United States to support more than the current population of China.
However the map says that those countries fall between 0 and 25% calorific food exporters. Compare this with what I said above: best figures I’ve seen suggest that India is almost certainly a net calorie exporter, and China probably is. The worst case scenario is both countries are essentially breaking even.
You certainly can’t conclude from that map that these countries are net exporters as opposed to breaking even, especially since the map is for just a single year. If you look at my first reference you will see that the the same organisaton that published that map states that India was a net food-exporter for the two following years.
But you’re right that nations today can’t be treated as closed systems, a point I made in my very first post. But it seems clear that Can Handle the Truth is discussing sustainable internal population, not anything related to international trade.
No, it doesn’t.
To illustrate this, look at those maps you prepared. On the east cost of China you will see two very large adjoining inlets and with a major city on the northern one. That city is Shanghai, and it is on the same latitude as the extreme south of Georgia
So as you can see the two countries are in no way on the same latitude. Something like 40% of China’s cropping land is in the subtropical or tropical regions. In comparison maybe 5% of the US and is subtropical, and none is tropical.
It can be easy sometimes to forget that China is a tropical country.
Yes, he says that being on the same latitude allows the same crops to be cultivated. This is why Florida can grow oranges, a crop native of China.
I can’t think of anything else Diamond ever said about latitude that is particularly relevant here.
Yes, he says that being on the same latitude allows the same crops to be cultivated. This is why Florida can grow oranges, a crop native of China.
I can’t think of anything else Diamond ever said about latitude that is particularly relevant here.
Since this is GQ can we please have a reference for his claim?
Let’s examine this claim.
The US has 175 million hectares of arable land. Let’s assume that even 1 million people in the US live in “McMansions and sprawling ranch homes” that are located on arable land, as opposed to being located on hillsides in Claifornia or the Nevada desert. And let’s assume that these “McMansions and sprawling ranch homes” on average occupy 5 hectares. So that’s 5 million extra hectares of extra arable land, or less than a 3% increase.
Can you explain how a 3% increase in arable land will “easily” allow the US to support more than the current population of China?
Yessss, and your point?
Most national parks have been preserved precisely because they weren’t settled early, and they weren’t settled early because they are unsuitable for agriculture.
I would expect that China has just as many military bases as the US.
Almost the entire state of Nevada is not arable land so its status is totally irrelevant.
And if land is can’t be farmed profitably the it almost certainly can not be farmeed sustainably. I would like to see some data on how much land capable of being sustainably farmed is currently lying empty in the US. I would geuss less than 100, 000 hectares.
Let’s say that the US has even 20 million hectares of such cropland. That gives us an extra 10% of arable land.
ITR champion can we please have some figures to back op the claims you’ve made here. Looking at the points you’ve raised I’m guessing we could get maybe an increase of 20% arable land in the US by the methods you suggest, most of it marginal. Can you please provide a reference that this sort of increase would easily allow the US to support the population of China?
Loo at the following figures for agricultural production from the FAI
Country Item Element Unit 2005 Year
China Cereals,Total Production Mt 423531448
China Fruit excl Melons,Total Production Mt 87055600
China Oilcakes Equivalent Production Mt 33418803
China Pulses,Total Production Mt 5490500 100
China Roots and Tubers,Total Production Mt 187320792
China Treenuts,Total Production Mt 1363400
China Vegetables&Melons, Total Production Mt 435024075
1173204618
1173204618 44.65890229
Country Item Element Unit 2005
United States of America Cereals,Total Production Mt 364019526
United States of America Fruit excl Melons,Total Production Mt 25872900
United States of America Oilcakes Equivalent Production Mt 71656063
United States of America Pulses,Total Production Mt 2096880
United States of America Roots and Tubers,Total Production Mt 19811380
United States of America Treenuts,Total Production Mt 1296390
United States of America Vegetables&Melons, Total Production Mt 39185160
523940304
It appears from that that even with the its major economic advantage the US still produces less than 50% of the food of China. How could an increase of 20% of marginally arable land easily make up that shortfall as you claim?
Since this is GQ can we please have a reference for his claim?
Let’s examine this claim.
The US has 175 million hectares of arable land. Let’s assume that even 1 million people in the US live in “McMansions and sprawling ranch homes” that are located on arable land, as opposed to being located on hillsides in Claifornia or the Nevada desert. And let’s assume that these “McMansions and sprawling ranch homes” on average occupy 5 hectares. So that’s 5 million extra hectares of extra arable land, or less than a 3% increase.
Can you explain how a 3% increase in arable land will “easily” allow the US to support more than the current population of China?
Yessss, and your point?
Most national parks have been preserved precisely because they weren’t settled early, and they weren’t settled early because they are unsuitable for agriculture.
I would expect that China has just as many military bases as the US.
Almost the entire state of Nevada is not arable land so its status is totally irrelevant.
And if land is can’t be farmed profitably the it almost certainly can not be farmeed sustainably. I would like to see some data on how much land capable of being sustainably farmed is currently lying empty in the US. I would geuss less than 100, 000 hectares.
Let’s say that the US has even 20 million hectares of such cropland. That gives us an extra 10% of arable land.
ITR champion can we please have some figures to back op the claims you’ve made here. Looking at the points you’ve raised I’m guessing we could get maybe an increase of 20% arable land in the US by the methods you suggest, most of it marginal. Can you please provide a reference that this sort of increase would easily allow the US to support the population of China?
Loo at the following figures for agricultural production from the FAI on total food production 2005 (Mt)
Country Item
China Cereals 423531448
China Fruit excl Melons 87055600
China Oilcakes Equivalent 33418803
China Pulses 5490500
China Roots and Tubers 187320792
China Treenuts 1363400
China Vegetables&Melons 435024075
Total 1173204618
Country Item
USA Cereals, 364019526
USA Fruit excl Melons, 25872900
USA Oilcakes Equivalent 71656063
USA Pulses, 2096880
USA Roots and Tubers, 19811380
USA Treenuts, 1296390
USA Vegetables&Melons, 39185160
Total 523940304
It appears from that that even with the its major economic advantage the US still produces less than 50% of the food of China. How could an increase of 20% of marginally arable land easily make up that shortfall as you claim?
In addition to what other posters have brought up above, you’re not addressing the question of for how long the United States could maintain a population of 1.5 billion people.
Could we fit 1.5 billion people into the land area of the United States?
Certainly
Could we produce and import enough food to feed 1.5 billion people?
Certainly
But the real question when it comes to population is: for how long will that population be sustained? Large populations in the past have tended to exhaust the natural capital of the area they live in. Iceland is an excellent example: even with it’s meager population, the approximate quarter of Iceland’s land area that was forested is now essentially down to zero and erosion of Iceland’s topsoil has drastically changed the nature of food production and land use. Iceland’s population now survives primarily on imports of food both from other nations and the surrounding oceans.
How long would the natural capital of the U.S. last if it were inhabited by 1.5 billion people? I don’t know, and I suspect no one does, but it’ll last a lot shorter than if the U.S. is occupied by 300-350 million people.
