Earth's habitability Human population growth

At Live Science: How many people can Earth support?

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Martin McGuigan  reports:

There are nearly 8 billion people(opens in new tab) living on Earth today, but our planet wasn’t always so crowded.

Around 300,000 years ago, when Homo sapiens likely first appeared, our total population was small, between 100 and 10,000 people. There were so few people at the start, that it took approximately 35,000 years for the human population to double in size, according to Joel E. Cohen, head of the Laboratory of Populations at the Rockefeller University and Columbia University in New York City. After the invention of agriculture between 15,000 and 10,000 years ago, when there were between 1 million and 10 million individuals on Earth, it took 1,500 years for the human population to double. By the 16th century, the time needed for the population to double dropped to 300 years. And by the turn of the 19th century, it took a mere 130 years. 

A very crowded Istiklal Street in the Beyoglu District of Istanbul, Turkey
Most experts think planet Earth can support about 10 billion people, and that when our population reaches that number, it will start to decline. (Image credit: Ayhan Altun)

From 1930 to 1974, the Earth‘s population doubled again, in just 44 years. But is the human population expected to continue growing at this rate? And is there an upper limit to how many humans our planet can support?

“The future of the world population is driven by a mixture of survival and reproduction,” Patrick Gerland at the United Nations (UN) Population Division in New York City, told Live Science. “If you have a ratio of two children per couple, then you can keep going to a more or less stable size of the population. Once you get to a number smaller than two, from one generation to the next, your population will shrink, or decline. If you are above that and the majority of people survive, then your population will grow.” 

Many low-income countries around the world have high birth rates and large family sizes, but also a high rate of infant mortality and shorter lifespans. But, Gerland said, “More and more countries, once they reach a certain stage of socioeconomic cultural development, tend to converge towards about two children [per couple] or fewer.” This means that while access to health care increases lifespans, suggesting population growth, this tends to occur in countries with a falling birth rate.

Global population growth peaked in the 1960s and has slowed since then. In 1950, the average birth rate was 5.05 children per woman, according to the UN Population Division(opens in new tab). In 2020, it had fallen to 2.44 children per woman. 

As Gerland explained, “Right now the scientific consensus is that the population of the world will reach a peak some time later this century. The world population is projected to reach 10.4 billion people sometime in the 2080s and remain there until 2100, according to the United Nations Population Division. But Gerland stressed the further that demographers look into the future, the more speculative and uncertain their predictions become.

Full article at Live Science.

19 Replies to “At Live Science: How many people can Earth support?

  1. 1
    Seversky says:

    Star Trek: The Original Series The Mark of Gideon

  2. 2
    jerry says:

    Someone once did a calculation based on future availability of energy and physical space using Earth plus surrounding orbits and came to the conclusion that the Earth could support a couple trillion people.

    That seems like a lot but then it’s possible to fit every human being into one cubic mile of ocean and there’s 330 million cubic miles of ocean. No one is suggesting that this is any way desirable but that there is a lot of space on Earth and maybe there will be ways to accommodate much more than we currently have.

  3. 3
    Seversky says:

    The carrying capacity of the planet is a much more complex problem than just resources. It’s not just the quantity of resources available, it’s also the infrastructure to move them to where they are needed.. Famines that have stricken parts of Africa, for example, have happened not because there is a world shortage of food. There is plenty of food available. One problem is the will and the means to get it to where it is needed in time. Another is how rebuild often ramshackle economies on a sounder and more durable footing. A third is whether a species that has evolved to be instinctively most comfortable in clan/tribal/village sized communities can adapt to form much larger but more durable social and political structures without coming to blows with each other as happens now.

  4. 4
    BobRyan says:

    Similar experts predicted most of humanity would be dead by now. Population growth and limited food was supposed to bring about our deaths that never happened.

    I read somewhere, not that long ago, that the entire population of the world can live in the state of Texas. Shows just how big Texas and the world are.

    Under the last Shah, new agriculture techniques made it possible to farm in the desert. Other innovative technology brought food to people who were otherwise starving.

    The technology exists to feed the world and bring medicine cheaply to those who need it. Those who need it are under dictatorship and warlords. Not to mention terrorist groups and various criminal organizations.

    People in the world suffer, because those controlling everything want to continue that control. They steal and destroy anything that is a threat to their power.

    without taking that into account, most suffering will continue.

  5. 5
    BobRyan says:

    As far as that example of 91% of COVID deaths being from those who had the shot, there are about 75% of the people who have had the shot. If those without the shot are supposed to be the ones dying, that 9% should be higher.

    The evidence proves the shots do nothing to save lives. In fact, those who rely on natural immunity, that God created, do better. I have gotten it a few times, with the first being a month before my state shut down. It felt like a lingering flu that was quite manageable. After that, it became a mild annoyance.

    There were plenty who got it before shutting down. It had already reached the world. Why shut down when just about everyone already had it.

    Wuhan is a major city in China with international airport. Covid was not discovered until October of 2019. By then, it was global and no one knew about it. If it was the projected death toll, where were the bodies?

    Not even a single cruise ship filled with mostly elderly people became a floating morgue. There were not many deaths for the biggest age group COVID targets.

    Every measure taken happened after the spread. There was no scientific reason to support shutting down, which is exactly what Dr. Scot Atlas told Trump.

  6. 6
    JVL says:

    BobRyan: As far as that example of 91% of COVID deaths being from those who had the shot, there are about 75% of the people who have had the shot. If those without the shot are supposed to be the ones dying, that 9% should be higher.

    Most of the unvaccinated are younger and less likely to even show symptoms when they do become infected.

    Again, why don’t you just look these things up?

    Wuhan is a major city in China with international airport. Covid was not discovered until October of 2019. By then, it was global and no one knew about it. If it was the projected death toll, where were the bodies?

    It’s hard to imagine how (or why) you keep getting things so wrong when it’s easy to look things up.

    The first confirmed human infections were in Wuhan. A study of the first 41 cases of confirmed COVID?19, published in January 2020 in The Lancet, reported the earliest date of onset of symptoms as 1 December 2019. Official publications from the WHO reported the earliest onset of symptoms as 8 December 2019. Human-to-human transmission was confirmed by the WHO and Chinese authorities by 20 January 2020. According to official Chinese sources, these were mostly linked to the Huanan Seafood Wholesale Market, which also sold live animals. In May 2020, George Gao, the director of the CDC, said animal samples collected from the seafood market had tested negative for the virus, indicating that the market was the site of an early superspreading event, but that it was not the site of the initial outbreak. Traces of the virus have been found in wastewater samples that were collected in Milan and Turin, Italy, on 18 December 2019.

    Every measure taken happened after the spread. There was no scientific reason to support shutting down, which is exactly what Dr. Scot Atlas told Trump.

    Scot Atlas is a radiologist not an infectious disease specialist.

    Atlas has spread misinformation about COVID-19. He claimed that children “have virtually zero risk of dying, and a very, very low risk of any serious illness from this disease” and “children almost never transmit the disease” although children can carry, transmit, and in some cases be killed by the COVID-19 virus. As of September 2021, 544 American children had died of COVID-19, 0.095% of all COVID-19 deaths. He expressed skepticism that face masks help prevent the spread of the virus, including in a tweet in October 2020 that Twitter removed after determining it was not accurate. Later that day, HHS official Brett Giroir, the Assistant Secretary for Health, reaffirmed that masks did work to prevent transmission of the virus. Dr. Deborah Birx, the White House coronavirus response coordinator, was reported to be “relieved” by the removal of Atlas’s tweet.

    He advised that the virus should be allowed to spread naturally among people deemed at low risk, while protecting the most vulnerable populations, so as to gain herd immunity. The Washington Post reported that Atlas was the leading proponent within the Trump administration for a herd immunity approach to the virus, although some experts cautioned that such an approach could lead to hundreds of thousands more American deaths. Atlas later denied that he advocated for the herd immunity strategy, said “there’s never been a desire to have cases spread through the community,” and said it “has never been the president’s policy.” However, in October and November 2020, he touted the Great Barrington Declaration, an open letter that calls for encouraging herd immunity. He advocated for in-person school reopening and resumption of college sports during the pandemic

    Atlas’s influence on policy alarmed many doctors and health experts. In September 2020, 78 of Atlas’s former colleagues at the Stanford Medical School signed an open letter criticizing Atlas, writing that he had made “falsehoods and misrepresentations of science” that “run counter to established science” and “undermine public health authorities and the credible science that guides effective public health policy.” Atlas’s lawyer Marc Kasowitz threatened to sue the researchers.

    Atlas’s comment urging Michiganders to “rise up” against measures to prevent COVID-19 transmission was widely condemned by health professionals and by Stanford University, home of the Hoover Institute where Atlas is a senior fellow. In November 2020, Michigan Governor Gretchen Whitmer denounced the tweet as “incredibly reckless” and Fauci said: “I totally disagree with it, and I made no secret of that. … I don’t want to say anything against Dr. Atlas as a person but I totally disagree with the stand he takes. I just do, period.”

    The same month, the Stanford University Faculty Senate, by an 85% vote, adopted a resolution condemning Atlas for his actions that “promote a view of COVID-19 that contradicts medical science.” The resolution cited Atlas’s statements and said they endangered the public.

    Again, you seem to only believe someone who touts beliefs that you like as opposed to considering all the opinions and data. But, considering how difficult it is for you to understand basic statistics and graph titles I guess you can’t interpret the data yourself.

  7. 7
    relatd says:

    BR at 5,

    I watched this carefully from the moment it started. It is very easy to contradict the bulk of what you say. Look at what’s happening in New Zealand right now. What happened in Australia? You present nothing to back up your claims. This indicates you are pushing a narrative, not factual information.

  8. 8
    Fasteddious says:

    John Brunner wrote a sci-fi novel called “Stand on Zanzibar”. The title was based on a calculation that the entire human population (at the time) could fit on that relatively small island. Ten billion now seems like a lot of people, and given out predisposition to damage or ruin what we own or live on, there is some danger to the planet and its other inhabitants in having that many people. However, as the fertility transition continues, more and more countries are falling below replacement level in birth rate. Only Africa and parts of Asia have higher birth rates than the 2.1 per woman needed to maintain a stable population in the long term. Most western countries are well below 2.0 now. Of course, it takes a generation to see the effects of changes, so it is no surprise that population will continue to rise for awhile. But then it will plateau, and probably start to drop if the average stays below 2.0.
    Various people have written about the “ideal” population for the world. Some claim we could (in principle) support a trillion humans, albeit with severe limitations and consequences for the rest of the planet. One sci-fi writer thought that 10,000 people would be ideal as that is the maximum number of people you could hope to meet personally in a lifetime. That seems a rather silly criterion. My own view is that one billion would be about right to keep the planet healthy and provide a robust society with a good living standard for everyone, but that isn’t going to happen in the next two centuries.
    I note that in most Star Trek episodes where the population of one of their ubiquitous planets is mentioned, it is usually around a billion. Perhaps that is their politically correct 1960’s comment on “over population”? Nowadays more people are concerned about the demographic collapse where fewer young people (workers) will be unable to support the growing number of older people (retirees). The way we structure our society and economics may have to shift, but please, not by WEF Reset edict!

  9. 9
    BobRyan says:

    I did get COVID in March of 2020, a month before my state shut down. I got it from someone at work and spread it to others, including my family.

    Wuhan International Airport does exist. It is WUH. Not something I made up.
    https://www.wuhan-airport.com/

    Wuhan is the capital of Hebei Province. It is not some little village in the middle of China, but an industrial city.

    https://www.britannica.com/place/Wuhan

    What are Fauci’s and Birx’s expertise in? AIDS, which has nothing to do with coronaviruses.

    Did anyplace that locked down completely stop the spread of anything? No. How do you stop something that already spread.

    Dr. Li discovered what appeared to be an outbreak of SARS in Wuhan. No one else noticed. He filed an official report in October of 2019. The CCP responded by threatening him until he recanted.

    Prior to his discovery, how many people carried COVID onto planes at the international airport? Unless it is being claimed that no one carrying it left the city?

    Lock-downs were being implemented due to people around the world already having COVID. Most who have it do not know they have it. That would be the vast majority. The tiny percentage of people who needed hospitalization did not justify shutting down, which increased suicides.

    Was the cure worth it? How many died due to increased suicides, ODs, drinking themselves to death, etc. Those were lives that would largely have been saved, since they would not have lost everything.

  10. 10
    JVL says:

    BobRyan: Did anyplace that locked down completely stop the spread of anything? No. How do you stop something that already spread.

    The virus is spread by close human contact so, to slow down transmission and keep the number of cases lower, you limit the number of contacts people make. This was all clearly explained (in the UK at least) and is just common sense when you think about it. You want to keep the cases low so that your hospitals are not overrun with serious cases. Of course everyone will, eventually, get exposed but the longer period of time that takes keeps the medical community afloat AND, in this case, meant a lot of people were able to get vaccinated before they caught the virus.

    Dr. Li discovered what appeared to be an outbreak of SARS in Wuhan. No one else noticed. He filed an official report in October of 2019. The CCP responded by threatening him until he recanted.

    Where is your evidence for this?

    Lock-downs were being implemented due to people around the world already having COVID. Most who have it do not know they have it. That would be the vast majority. The tiny percentage of people who needed hospitalization did not justify shutting down, which increased suicides.

    Apparently you didn’t even watch the news or read about hospitals that were running out of beds and ventilators and PPE. Have you even looked at the excess death data? Have you bothered to even check anything which contradicts your beliefs? People all over the planet were dying in hospitals. Hundreds of thousands. This is the truth.

  11. 11
    ET says:

    Seeing that we are killing our soil, the earth will not be able to support many people by the year 2100.

  12. 12
    ET says:

    Yes, people with vitamin and mineral deficiencies died from COVID-19. It was a global Darwin Award.

  13. 13
    asauber says:

    “watch the news or read about hospitals that were running out of beds”

    In my area, they opened a convention center room with full of extra beds and then closed it again after awhile because no one was using it.

    I think hospitals run close to capacity as much as they can because empty beds mean wasted $$$.

    Andrew

  14. 14
    JVL says:

    Asauber: In my area, they opened a convention center room with full of extra beds and then closed it again after awhile because no one was using it.

    Yes, this happened in the UK as well because the bureaucracy was a bit slow finding funding to supplement the capacity of the hospitals that were almost sunk by the number of patients. The system was tested to the limit, almost broke, but survived. And yes, I know people who work in the UK’s NHS and yes they have confirmed that.

    I think hospitals run close to capacity as much as they can because empty beds mean wasted $$$.

    I suspect no one wants to pay for extra capacity if it’s not likely to be used. Which is why an even mildly deadly pandemic can cause the system to hit a crisis soon. Again, good reasons to slow down the rate of infections via isolating and ramping up the production of a viable vaccine.

  15. 15
    JVL says:

    ET: Seeing that we are killing our soil, the earth will not be able to support many people by the year 2100.

    That is one of the frighting possibilities that few people talk about or address. I think people have a hard time dealing with things that might happen after they’re dead. Also there’s a problem with pollinators.

  16. 16
    BobRyan says:

    JVL and others who were not paying attention to the beginning of COVID.

    There was only one doctor who noticed symptoms in October of 2019. Clusters of elderly were dying, which gave the appearance of SARS. No one else noticed it, since no one was looking for it.

    He was vocal about it, which resulted in the CCP sending police to threaten him until he recanted. BBC and others reported on him in February of 2020. How long had COVID been happening unnoticed until October? How far had it already spread?

    https://www.bbc.com/news/world-asia-china-51364382

  17. 17
    BobRyan says:

    There are some people who have believed since the 70s that the population needs to be reduced. It does not matter how many times their predictions have been wrong. They continue to believe there is going to be something that causes humanity to largely die off in the future.

    To get population reduction they want, they use whatever is convenient to reduce human beings to something more manageable, like COVID, since shutting down was going to bring an increase in loss of life. Suicides, ODs, murders all increased in places that shut down, which was warned would happen.

    There is also an attempt to do away with fertilizers, which is resulting in less food being produced by design. They would rather some starve to death now than many later.

  18. 18
    Trumper says:

    Hey Rob….. good job kicking JVL to the curb on most the silly comments made. I appreciate your factual and steady statements. I about laughed myself off my seat when JVL proclaimed that lockdowns worked in slowing the inevitable…… I get it… maybe it would be good to not overwhelm hospitals…. but then again …maybe it would be good to not force many kids to suicide…. and millions others to ignorance by dropping fully out of schools…. or forcing tens of thousands to get sick by taking an experimental shot (not a vax…anyone calling it a vax should log off now … and go back to something more simple in life)

  19. 19
    JVL says:

    BobRyan: There was only one doctor who noticed symptoms in October of 2019. Clusters of elderly were dying, which gave the appearance of SARS. No one else noticed it, since no one was looking for it.

    I’m beginning to think that you are actually a plant of some kind ’cause you keep repeating the same thing without justifying it even though you’ve been asked over and over and over again.

    So, again, what evidence do you have that COVID-19 was first observed in October 2019? The links you’ve provided are to stories which say December 2019.

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