How Many People Can Earth Support? – IOTW Report

How Many People Can Earth Support?

From 2011-

LiveScience-

The late-18th century philosopher Thomas Malthus wrote these ominous words in an essay on what he saw as the dire future of humanity. Humans’ unquenchable urge to reproduce, Malthus argued, would ultimately lead us to overpopulate the planet, eat up all its resources and die in a mass famine.

But what is the maximum “power of the Earth to produce subsistence,” and when will our numbers push the planet to its limit? More importantly, was Malthus’ vision of the future correct?

Many scientists think Earth has a maximum carrying capacity of 9 billion to 10 billion people. [How Do You Count 7 Billion People?]

One such scientist, the eminent Harvard University sociobiologist Edward O. Wilson, bases his estimate on calculations of the Earth’s available resources. As Wilson pointed out in his book “The Future of Life” (Knopf, 2002), “The constraints of the biosphere are fixed.”

Aside from the limited availability of freshwater, there are indeed constraints on the amount of food that Earth can produce, just as Malthus argued more than 200 years ago. Even in the case of maximum efficiency, in which all the grains grown are dedicated to feeding humans (instead of livestock, which is an inefficient way to convert plant energy into food energy), there’s still a limit to how far the available quantities can stretch. “If everyone agreed to become vegetarian, leaving little or nothing for livestock, the present 1.4 billion hectares of arable land (3.5 billion acres) would support about 10 billion people,” Wilson wrote.

The 3.5 billion acres would produce approximately 2 billion tons of grains annually, he explained. That’s enough to feed 10 billion vegetarians, but would only feed 2.5 billion U.S. omnivores, because so much vegetation is dedicated to livestock and poultry in the United States.

So 10 billion people is the uppermost population limit where food is concerned. Because it’s extremely unlikely that everyone will agree to stop eating meat, Wilson thinks the maximum carrying capacity of the Earth based on food resources will most likely fall short of 10 billion. [When Will Earth Run Out of Food?]

According to population biologist Joel Cohen of Columbia University, other environmental factors that limit the Earth’s carrying capacity are the nitrogen cycle, available quantities of phosphorus, and atmospheric carbon concentrations, but there is a great amount of uncertainty in the impact of all of these factors. “In truth, no one knows when or at what level peak population will be reached,” Cohen told Life’s Little Mysteries.

Slowing growth

Globally, the fertility rate is falling to the “replacement level” — 2.1 children per woman, the rate at which children replace their parents (and make up for those who die young). If the global fertility rate does indeed reach replacement level by the end of the century, then the human population will stabilize between 9 billion and 10 billion. As far as Earth’s capacity is concerned, we’ll have gone about as far as we can go, but no farther.

27 Comments on How Many People Can Earth Support?

  1. Well, in all honesty, we were given the directive to fill the earth. As of right now, every person could live on the North American Continent with the rest of the world used for growing food:{https://www.fastcompany.com/1665327/infographic-if-7-billion-people-lived-in-one-city-how-big-would-it-be}.
    So my guess would be that we could get another 7 billion in Asia and still have enough landmass in the other continents for plenty of farming. The commute to get there every day just to plow fields and feed the herds would be pretty long though, so it isn’t likely that we get everybody to live here.

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  2. Sort of depends on where you live doesn’t it? Seems as though places such as NK, India, Venezuela and possibly China are already falling short…..but I could be wrong. Often totalitarian governments impose near starvation on their subjects in order to keep the subjects in line.
    “The first stage in the corruption of morals is the banishment of truth …”
    Michel de Montaigne

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  3. These sorts of musings by city dwellers in the academe are incredibly boring, and useless. I despise these people with the patches on their elbows and meerschaum pipes, tugging at the intellectual chins in deep thought. Piss off. None of the doomsday prophets from a century or more ago even came close. Shit Algore was wrong two decades ago.

    Please do a magic trick and disappear up your own asshole forever.

    Bye.

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  4. “If everyone agreed to become vegetarian…”

    The only way that would happen is under a totalitarian global government, which would kill off a couple billion people on its way to power, and ten million more at regular intervals after that, so we’d never know the upper limit.

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  5. I’d say we’re getting there … look up ‘Universe 25’

    btw, ‘fresh water’? … read a stat once that said it rains every day to give every person on the planet about 750,000 gallons of water …. that’s EACH, for the Brian Williams’ out there

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  6. As long as we’re theorizing and philosophizing, how many of the millions aborted might have had some solutions to those problems had they been allowed to live?

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  7. I would agree with Menotu. But you also have political stupidity. Ten years ago a white farmer in South Africa fed his family and about 125 other people. The farmer’s of color had problems feeding their own family. In America today the American farmer feeds his family and 145 other people.

    The high production agricultural areas of the US midwest, southeast, and California, Brazil, Chile, Ukraine, Bavaria, Spain, and Central America if properly managed with state of the art equipment, fertilizers, and pesticides would produce more than twice the vegetables and grain what the world needed. The plains in the world if properly managed could produce 3 times the beef, mutton, chicken and pork needed with grain supplements from the dirt farmers. Then their are the fisheries that could be better managed and set up in coastal regions all over the world.

    There is too much waist and mis-management of our current resources. It could be done better. Canola would be a better source of biodiesel with diesel at $250 a gallon or higher. Corn as an ethanol additive is not financially viable unless gas is over $3 a gallon.

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  8. Isaac Asimov was a professor of biochemistry at the Boston University School of Medicine before he became one of the world’s greatest writers of science fiction. Asimov calculated that Goddess Gaia can support four-zero-comma-zero-zero-zero-comma-zero-zero-zero-comma-zero-zero-zero-comma-zero-zero-zero people. That’s right Asimov proved in, “The Good Earth Is Dying,” “Der Spiegel, no. 21, 1971, that Earth can support 40 TRILLION (!!!) people.

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  9. Yeah well okay but “sustain” wouldn’t be my wish. The world already is too crowded.

    In my lifetime, the population of the United States has more than doubled — and it was nicer before.

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  10. Why the hell should the planet support anybody? Fudge man, grow up and get a job.

    Ain’t the Earfs job to tell you when to get up just so you can eat cereal and watch cartoons all damn day.

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  11. A corn kernel dropped in a planter outside a (Iowa?) coffee shop and presumably watered by discarded coffee grew 17 full ears by years end. Do you think anyone calculated for that in their grand predictions?

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  12. Menotu
    MARCH 9, 2020 AT 5:36 PM
    “I failed to see the obvious answer: All of them.”

    …I remember reading a book on the last American registered cruise ship by its Captain, and he was recounting questions his elderly passengers asked him.

    One such was a sweet old woman who, noticing the pursers and bellboys, deckhands and maids, asked him, “How many people work on this ship?”. He told her, “About 1,400”.

    “Oh, my”, she said, “my, my, my”.

    Then, after thinking for a moment, she followed up by asking him, “and do they all sleep on board?”.

    …he says he’s thought of a better answer every year, but at that time, he could only manage a stranged “yes” without laughing…

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