June 8, 2015

Scientists more worried than public about world’s growing population

Total World Population

Over the course of history, many scientists and activists have raised alarm about population numbers that only increase every year.

When the English scholar Thomas Malthus published An Essay on the Principle of Population in 1798, the number of people around the world was nearing 1 billion for the first time. “The power of population is indefinitely greater than the power in the earth to produce subsistence for man,” he wrote then.

World Population GrowthSkip ahead to 1968, when the world’s population had risen to around 3.5 billion and the annual rate of growth peaked at 2.1%: American biologist Paul Ehrlich revisited the Malthusian principle in his bestseller The Population Bomb, starting a movement to hedge the trend. “The basic point is so simple,” Ehrlich told Retro Report. “We have a finite planet with finite resources. In such a system, you can’t have infinite population growth.”

In 2015, the global population is an estimated 7.3 billion, according to the United Nations, and many of Malthus’s and Ehrlich’s predictions have yet to come true or have been proven false (such as the “increasing” death rate, which has actually decreased).

According to a pair of 2014 Pew Research Center surveys, however, today’s scientists are more likely than the general American public to be concerned about population growth, though not necessarily to the extent that Malthus and Ehrlich were.

Views of Population GrowthAsked whether or not the growing world population will be a major problem, 59% of Americans agreed it will strain the planet’s natural resources, while 82% of U.S.-based members of the American Association for the Advancement of Science said the same. Just 17% of AAAS scientists and 38% of Americans said population growth won’t be a problem because we will find a way to stretch natural resources.

Americans used to be much less concerned about population growth, according to Gallup polls: In 1959, three-quarters (75%) of Americans had heard about the “great increase in population” predicted for the world during the coming decades, but just 21% of Americans said they were worried about it. And when comparing population concerns with a list of global threats, a 1997 Pew Research Center poll showed that Americans were more worried about other potential risks.

Looking ahead, it’s still unclear what the population trajectory will be. The UN says that population will continue to grow throughout the 21st century, predicting with 80% confidence that it will reach somewhere between 9.6 billion and 12.3 billion people by 2100.

Growth is expected to occur mostly in Africa, and abate in the Americas, Europe and parts of Asia, especially as families in more-developed nations have fewer children than they used to have. In many countries in the latter regions, the total fertility rate has dropped below the “replacement rate” of about 2.1 lifetime births per woman. The total fertility rate in the U.S., for example, fell to 1.86 in 2013.

This leads to yet another population worry over whether there are enough young people to take care of the older populations, as lifespans continue to increase and fertility decreases in certain parts of the world. Concerns about this issue are more common in Japan, South Korea, China, Germany and Spain, according to our 2013 global survey.

Topics: International Threats and Allies, Demographics, Population Projections

  1. is an associate digital producer at Pew Research Center.


  1. Anonymous1 year ago

    i find this article very factual and interesting 😀

  2. Ruth Scott2 years ago

    Just as the body was designed to renew itself the earth was designed with resources enough to last forever some of us will not be here to enjoy the earth,however Jehovah will never allow man to destroy his creation our beautiful planet !!!

    1. jake2 years ago

      Jehovah is not real ….it’s the same as the Easter Bunny only for adults naive enough to believe in it

      1. Anonymous1 year ago

        my words to a t

      2. Anonymous1 year ago

        Jake, Jehova is real. Galatians 6:7 “Do not be deceived:God cannot be mocked A man reap what he sows…

  3. Will2 years ago

    The US and Europe need to have more children and dependant nations that have >4 children per mother need to have less. When we stop foreign food aid, this problem will correct itself (through extremely horrible conditions). If we want these conditions to be less horrible for the people of these high growth rate dependant nations, we should gradually slow the foreign food aid…starting now.

  4. kokokokkoko2 years ago

    preach it

  5. Cassandra Y.2 years ago

    Population growth is increasing. And earth does not have an infinite supply for us to use. Living in a sustainability economy is what we should do but from the amount of resources we have left is terrifying. Renewable sources are used quicker than they can renew themselves. And have you noticed the depletion of fishes in the sea? Due to over-fishing, our ocean’s ecosystem is changing. Deforestation is increasing. Population growth and our needs are keeping us at stake! Our needs can’t be supplied by the earth forever. And as our population continues to increase, the earth’s resources decrease.

  6. Jon romano2 years ago

    Due to the progress in medicine , the human life span has increased and keep on encreasing. The earth resources don’t.The balance bet. Natality and mortality is progressively becoming “unbalanced”. The progress is generated by replacing the “old” with the “new”. Malthus was right: the wars and plagues are necessary. They do not happen sufficiently often, therefore controlled reproduction becomes a must. It must be done selectively.

  7. Gail N2 years ago

    Looking at your chart in percentages, an interesting fact emerges. The percentage of the population which is dependent, the young and the elderly, remains roughly constant over time. If anything, this percentage declines slightly with the passage of time. This is true for the data you show for the US and globally. It is undoubtedly clear that a person aged 6 or less cannot be self-supporting while it is not entirely clear that a person aged 64-70 cannot contribute to their own support. Yet you raise a concern ” over whether there are enough young people to take care of the older populations.” I suspect this is simply an echo of a meme put out by conservative think tanks who seek to plant concerns over our social security system.

    What your article fails to point out is that when populations have a very high percentage of young people, especially young men, and when that is combined with an economy which cannot find work and a way for these young men to become productive members of society, that we then have outbreaks of extreme violence, barbarism and war. That experiment is being played out now in Africa and the Middle East.

    What would be more interesting would be a chart that extrapolates out past the current bulge in population coming from a time where effective birth control was not available, women had fewer rights, and higher living standards all pushed the population higher. I suspect a stable population number would emerge, hopefully much, much lower than 11 billion by say the year 2200 or even 2300. Automation, renewable energy, and increased longevity will hopefully make the lives of this smaller number of our species more enjoyable overall.

    While your article nicely presented the data, it did not go nearly far enough to actually do any real analysis of the same.

    1. Nyara Chan2 years ago

      The unique reason why the dependency ratio in the U.S will not be high is because immigration, and to certain extent, the same will be on the United Kingdom, France and Germany if they open a bit more their immigration policies. The world on average will not suffer too much from the dependency ratio just because the life expectancy isn’t just high in the poorest countries, specially India. But, this is just “the world in average”. The low dependency ratios will be only available in a hand of countries, most of them extremely poor, so the countries with the high dependency ratios will have to find a way today to use their labor in a effective way or they will face severe problems, like Japan is doing now.

  8. Mike Stasse2 years ago

    The research I’ve seen totally disagrees with this. Seeing as we are reaching Peak Everything, and that we have to seriously curtail economic and industrial production if we have any chance of not going over 2 degrees C by 2100, I can’t see how we can continue feeding a growing population.

    The Club of Rome forecast a crash in population starting in 10 to 15 years time in their ‘standard scenario’. This scenario is bang on target according to Dr Graham Turner, and from where I sit, I reckon he’s right.


  9. Lee Miller2 years ago

    One has to wonder what the background of the 17 percent of scientists who view the population growth problem as not a problem. I hope that none are biologists or ecologists. I suspect they are scientists who don’t deal much with species and nature, but with test tubes and particle collisions.

  10. Prof Bob2 years ago

    According to an article in Science Daily (April 20, 2009), a survey of the faculty at the State University of New York, which has a very strong environmental science department, the planet’s major environmental problem is overpopulation.. Climate change is second. This echoes the theme of the popular free ebook series “And Gulliver Returns” –In Search of Utopia—(andgulliverreturns.info) As one professor at SUNY said “With ten million or even a hundred million people on the planet there would be no warming problem.” It is both the technology and the number of people using it that create so many of our planetary problems.

    1. John Jorgensen2 years ago

      Thanks for the links 🙂

  11. Dilip Kumar2 years ago

    It is a serious matter for our concern to check the population growth otherwise we will loose our all development.

  12. PLB2 years ago

    So how many people were polled?
    And how can they be comparing polling in the past with now? Did they poll the same people or other people? How reliable is this information anyway?

    And if population is such a problem for some, have they sterialized themselves? They if you want to ‘improve’ the world, you better start with yourself.

  13. B.L. Ketchum2 years ago

    The issue; of too few young people to support the old; is finite in nature. We old people die. With a stabilized or declining population the ratio will eventually come back into balance. In the short term, greater effort MUST be made into preparations for our own declining years.
    Humanity is only a part of the life of this planet. For us to control the populations of the other life forms and let ourselves bred indiscriminately is not only disgusting but IMMORAL.

  14. Marian2 years ago

    I agree with Zero Population Growth and other organizations which encourage population control. We can do it voluntarily or our decendants will be requied to do it.
    It would be great is all children could be wanted children. That is more likely to happen if the couple has access to birth control. It should be their decision. Reproductive choice has been the major reason for a decrease in abortions. Unfortunately some religions and some politicians are interfering with access.

  15. Concerned nonscientist2 years ago

    Increasing overpopulation and climate change are virtually certain to have catastrophic global effects. The question is not whether but when. Have a look at Stephen Emmott’s book, TEN BILLION for a serious prospectus.

  16. Chickster2 years ago

    Undoubtedly the number one problem facing the planet. We can haggle all we want about the secondary effects such as water shortages, climate change, food shortages, etc. but until we confront overpopulation we are only akin to a bunch of noisy monkeys in a cage.

  17. John Seager2 years ago

    Under the UN medium projection, a substantial group of mostly poor, mostly African nations will see their populations grow by 3.5 billion from 1.2 billion to 4.7 billion by 2100. This is equal to 100% of the projected net global population growth. The nearly inevitable extreme local calamities will have global consequences – as will climate change, which is driven by both consumption and population growth.

    It’s not too late to bend the curve through expansion of voluntary family planning. But seemingly urgent problems have a way of postponing efforts to avert long-term adverse consequences.

    John Seager
    Population Connection

  18. Erik Kengaard2 years ago

    “At one time or another, acceleration of population growth . . . has been sought by militarists in need of cannon fodder, by rulers in search of hegemonic expansion, by industrialists in want of cheap and docile labor, by ecclesiastical spokesmen in search of souls, and by land and other speculators hungering for unearned increment.” Joseph J Spengler

    ” . . . the greatest destroyers of man’s options are the growth and excessive concentration of population.” Joseph J Spengler

    “. . . growth and concentration of population are processes that . . . are reversible only at very great, perhaps intolerable, cost.” Joseph J Spengler

  19. Jukka Aakula2 years ago

    The truth is the problem is mainly Africa.

    UN has already accepted the fact Africa is different what comes to population growth and what comes to HIV epidemy:

    “The new study also says Africa is likely to see the largest increase in population — from about 3.5 billion to 5.1 billion people — during the next 85 years.
    United Nations Population Division Director John Wilmoth, one of the study’s authors, says researchers previously anticipated population trends in Africa would follow patterns in other countries, increasing at a slower rate as birth control use became more widespread.

    But that has not turned out to be the case.”


    “Dr. Kevin de Cock of the World Health Organization: “[T]here will be no generalised epidemic of Aids in the heterosexual population outside Africa.”

    “A 25-year health campaign was misplaced outside the continent of Africa,” the article concedes, daring you hang them all. And so they’re quick to add a massive fiction: “But the disease still kills more than all wars and conflicts””


    1. sherwood2 years ago

      There are 1.1 billion people on Africa. Not 3.5.

      1. Brooks Bridges2 years ago

        Why should anyone pay attention to your blank statement?
        The other person left a link which is a believable source.

        1. Bob Rogers2 years ago

          No reference or not, the number seems to be more accurate. I’ve found several references corroborating that is closer to 1.1B. This UNICEF report is the best…


  20. RKae2 years ago

    Well, I kind of sort of thought we’d be on other planets by this point.

    Nope. A half-dozen walks on the moon and then (wow!) low Earth orbit for several decades. Now we don’t even have a damned shuttle!

    The promise of the Space Age sure fizzled out quickly!