Are There Too Many People on the Planet?

By Peter Kareiva

Before you read any further, please answer the question in the headline. Finished? Now read on.

I’m guessing that a lot of you answered yes. Now let’s think this through: We have 7 billion people on the planet.

  • Were 5 billion too many?
  • Were 3 billion people too many?
  • Were 1 billion people too many?
  • Were 1 million people too many?

How would you make those decisions? I doubt any real science comes into play. Yet at a recent meeting of the Society for Conservation Biology, I was in a conversation with several colleagues in which one person said there are too many people on the planet—and everyone nodded in agreement. This statement, together with the group’s certainty of its truth, offers a revealing window into conservation.

Here’s what I bet goes on when this question is posed—and I want to say up front that I think this way myself. I do not like long lines and traffic jams. I do not like that I have to drive 60 minutes to get to a decent natural area or that when I get to the Cascades for my hike, I’m likely to run into dozens of others on the same trail. I do not like how built up our coastline has become and how hard it is to get access to beaches. And so on.

In other words, I do not like the impact of “too many people” on my personal happiness. Rarely do we admit that this is the basis of our concerns about human population. Instead, we couch them in terms of “exceeding the Earth’s carrying capacity” or “causing the extinction of species.”

For example, one common mantra is that we are already using up the equivalent of 1.5 Earths—so how could we add even more people? But that refrain is based on an ecological footprint calculation that is deeply flawed and has been widely critiqued in the literature. (1, 2) The simplest way to expose the fallacy of the ecological footprint calculation is to emphasize that, simply by planting half the U.S. area with eucalyptus, we could change the current total human footprint from 1.5 Earths to only one Earth.

The other mantra is that an excess of people is causing the extinction crisis. I certainly agree that people are, sadly, causing extinctions, but I am not convinced it is a “number of people” issue per se. The most spectacular and massive extinctions of megafauna were associated with human populations of fewer than 1 million—the so-called “Pleistocene overkill,” when humans entered North America from Asia. During that period, the world lost mammoths, giant sloths, saber-toothed tigers, the dire wolf, giant beavers, and numerous other awesome species that would today inspire and enthrall us if they still existed. It did not take 7 billion people for this to happen. In fact, these extinctions occurred at extremely low population densities. (3)

And when we so easily jump to the conclusion there are too many people on the planet, what solutions does it suggest? Who should be eliminated? Who should not be allowed to have children? And who gets to decide? Is it really that there are too many people on the planet? Or is it more about the kinds of settlements and economies we have built?

Lastly, the entire notion of too many people neglects those studies showing that large numbers of people, especially concentrations of people in cities, are engines for innovation and cultural advances. (4) For example, new patents and inventions overwhelmingly come from cities—and the larger the city, the more patents and inventions are produced.

Given all this, I still think there are probably too many people on the planet. But I’m a little embarrassed by that sentiment—I know there is no clear analysis behind that conclusion and that it is to some extent a reflection of the fact that occasionally I like to get away from people. More importantly, the question of whether there are too many people is the wrong one for conservationists to ask. The right questions are: What quality of life do we want all people on the planet to share? And how can we achieve that quality of life while preserving as many species and ecosystems as possible?

Conservation of nature has a lot to contribute to answering those questions and to enhancing that quality of life. So don’t automatically nod in agreement when a colleague says: “The problem is, there are too many people on the planet.” People can be the solution as well as the problem.

Peter Kareiva is chief scientist for The Nature Conservancy and author of six books, including Conservation Science: Balancing the Needs of People and Nature (Roberts & Company 2010).

1. Van Kooten, G.C. and E.H. Bulte. 2000. The ecological footprint: Useful science or politics? Ecological Economics 32:385-389.

2. Fiala, N. 2008. Measuring sustainability: Why the ecological footprint is bad economics and bad environmental science. Ecological Economics doi:10.1016/j.ecolecon.2008.07.023.

3. Alroy, J. 2001. A multispecies overkill simulation of the end-Pleistocene megafaunal mass extinction. Science doi:10.1126/science.1059342.

4. Bettencourt. L.M.A., et al. 2007. Growth, innovation, scaling, and the pace of life in cities. Proceedings of the National Academy of Sciences doi:10.1073/pnas.0610172104.

Illustration by Anny Arden



  • Jon Frum December 8, 2012 at 12:00 pm

    Next time you are in a conversation with conservation biologists, ask them your question: how many people should there be in the planet? Then, ask them ‘and which people shouldn’t be here?’And please insist on an answer. The recent increase in global population didn’t come from people whose families were residing in the United States fifty years ago. Any increase in the United States comes from immigration. The increases are in Asia, Africa and South America. So exactly where would they remove the ‘excess’ population from? Please ask for a continent-by-continent breakdown of excess humanity.

    One thing I know – you won’t be invited back.


    • Scott December 25, 2012 at 9:39 am

      John, I respectfully submit that forcing the question of ‘which people shouldn’t be here?’ is the wrong question to ask. What’s the point of that? I don’t think anyone in this forum is suggesting that groups of people should be removed from the population. I don’t anyway.

      If you yourself believe that there are too many people in the world, then a better question is…what’s the solution? So if I were in front of you, I’d pass on your forced question, and re-focus on the problem (if you agree with it), specifically, “what, in your opinion, is the the solution?”


      • Tonyn January 31, 2013 at 6:33 am

        The societies in the world need to be educated about the truth in carrying capacity of the earth .
        Don’t beat around the bush tell the truth .
        People will regulate themselves better if they have a understanding rather than no understanding at all . Everything has Limits to what it will produce . sure advancements in tech and science has extended the supply over the years since WW2 , but its Not keeping up now have not for some time . We have been eating more than we produce since 2006 as a world and this has the Elite Power Financiers stalling the means to produce . Pay attention to what they say in the youtube video at frame 1:45 ,

  • Dave Gardner December 9, 2012 at 6:17 am

    Please pardon my taking exception to much of what is written in this piece.

    Most of the arguments here do not disprove the hypothesis that the world is overpopulated. The idea that we may just need to rearrange the way we live is far from scientific proof that Earth can sustain 7 billion of us. The fact that densely populated cities may be engines of innovation has nothing to do with whether the world is overpopulated. Even the fact that there were significant extinctions at times with smaller populations does not disprove the existence of overpopulation today. So one is left to wonder exactly what the purpose of this commentary is.

    While this list may not be conclusive proof, it is a pretty clear indication human numbers have reached a point that we cannot manage our affairs in a sustainable way:

    climate change
    massive species extinction
    depletion of aquifers
    rivers over-appropriated
    toxification of our freshwater
    ocean dead zones
    fisheries decline
    fertile soil depletion
    doubling of resource prices in the last decade
    continued large-scale hunger

    Being embarrassed at feeling your quality of life is lower due to the number of people in your community, your state, your country, or the world, is one of the things that prevents us from dealing with the issue of overpopulation effectively. Don’t be embarrassed. If we have to give up quality of life because we are afraid to talk about overpopulation, then we will get what is coming to us.

    Another is repeating the tired, completely off-the-mark mantra about who should be taken out, if indeed we are overpopulated. Those truly interested in the science, and not just interested in distracting us from the problem, know and will tell us that we can humanely, voluntarily reduce human population significantly over the next century simply by choosing to limit our own family size. Fear not; no one has to be executed.

    Making contraception more accessible, giving women more equality in these decisions, and making accurate information about overpopulation available are all important ingredients. Let me repeat: making accurate information widely available. Being embarrassed and spreading disinformation are really not helpful.

    Dave Gardner
    Director of the documentary
    GrowthBusters: Hooked on Growth


    • Rob Moir December 11, 2012 at 12:06 pm

      climate change is caused by industrialization putting out too much carbon – not overpopulation;
      massive species extinction is cause by over harvesting, habitat destruction and American consumerism – not overpopulation;
      depletion of aquifers is caused by industries drawing too much water without regulations and injecting too much pollution back in – not overpopulation;
      rivers over-appropriated caused by inadequate stewardship and regulation – not by overpopulation
      toxification of our freshwater is caused by mismanagement and pollution both of nitrogen that causes harmful algal blooms and by toxic chemicals – not by overpopulation
      ocean dead zones are caused by too much nitrogen coming off the land (where it could be reused)feeding toxic algae blooms not by overpopulation;
      fisheries decline is caused by overfishing and degradation of ocean habitats by pollution – not by overpopulation;
      fertile soil depletion caused by poor practices and mismanagement – not by overpopulation;
      doubling of resource prices in the last decade is happening in America despite there not being a big population increase and a 10% increase in consumerism every year- not by overpopulation;
      continued large-scale hunger is a political problem of “the haves” exerting power over the hungry – not an overpopulation problem.
      Bangladesh has been called overpopulated Without a hunger problem, it is self-sufficient for agriculture, food and water.


      • Rob Moir December 11, 2012 at 12:37 pm

        Dave, I applaud your film Growth Busters. For a sustainable society we must stop America’s burgeoning growth in consumerism and destructive short-term cost-cutting by industries. With America only 4% of the world’s population and 20% of the carbon emissions, we alone are one fifth of the drivers of climate change. To show in your film a scientist saying that population is part of the problem is fake science. It is his belief, his leap of faith not based on facts. You portray the population “bomb” belief of a few scientists as science. Putting up a false scapegoat, over population, does not help us solve the problem of over-consumerism and bad stewardship. Kareiva sheds light for how there is a causal relationship between America being the society most in need of “growth-busting” and at the same time one of the least populated nations in the world. We expect to have much because we can, the media tells us so. Look to the evidence instead citing the dogma.

      • Dave Gardner December 11, 2012 at 5:45 pm

        Well, I see. Rob gives us a long list of all these things we are just doing wrong. We just can’t seem to get those right. And having this huge number of people on the planet has nothing to do with it. All we have to do is manage everything we’re doing differently, perfectly, and then it will magically serve 7 billion or more fairly, adequately and sustainably. I’m sorry, but this is just delusional thinking.

        I’m not saying overpopulation is the only problem. Not by a long shot. Overconsumption is a huge part of it. But I am quite certain and quite confident that we will not solve this list of problems if we ignore population’s role in the equation. There are quite a few scientists, actually, who understand this.

      • Rob Moir December 13, 2012 at 8:59 am

        Fine, but please do not waste practitioners time carping about population when there are so many more pressing problems that Americans must work harder on. It is okay for over population to be an academic problem of scientific understanding. Perhaps an improvement over scientists deliberating on how many angels could fit on the head of a pin. To be sure there will be push back when Americans start doing something about global population. There is a vast amount of social science understanding of what is wrong with solving someone’s perceived over population problems. It is best to make room for others and collaborate.

      • Scott December 25, 2012 at 10:02 am

        My opinion is that Dave’s right on the mark. Overpopulation isn’t the only problem, but it’s the biggest problem. One could argue that politics and disorganization play a role into the mess. But some of what you listed, Rob, plays against human nature and man’s continued irresponsible consumption habits. As a species, we’re still by and large asleep at the wheel regarding growing global problems.

        You listed pretty advanced concepts as your reason for various problems. Some of them are doable but sadly, based on how slow human beings are to respond, changes will take a while to develop. For others, like ‘large-scale hunger is a political problem of the haves exerting power over the hungry’, there really is no solution. That’s human nature. What’s your solution to that? What can I do about a foreign, strong-arm dictator who keeps food from his country’s the poor? Diplomacy? Force?

        You repeatedly say that overpopulation isn’t the problem to various issues…but, in my opinion, it’s the root problem for every point you made.

      • Patzer March 8, 2013 at 8:56 pm

        Bangladesh is not the best example to cite as not being overcrowded and self sufficient. Although there may be something contaminating the groundwater in large amounts and it could have come from when it was still part of India and governed by England from the manufacture of textiles which had declined from the American Civil War. So it could be natural changes in the rocks, manufacturing processes, foreign wars leading to cotton growing and cloth, but not overpopation. Well so far, I personally would rather us local sewage treatment plans and water over here than just about anywhere else. At least anywhere else that I know of so far, and we can always adapt what we have better than most, well, most that I know of.

      • Patzer March 8, 2013 at 8:59 pm

        Please don’t comment of my grammer. I think I’m tired tonight.

      • C A Featherly January 17, 2015 at 10:22 am

        Everything that Rob cites as not being caused by overpopulation is done by people. Few people = less devastation. Sure responsible conservation is part of the answer but it alone is not the solution. Population reduction must be added or it just becomes delaying tactics.

      • Dar October 8, 2015 at 5:20 am

        “au contraire”

        Nearly everything you outlined has a direct correlation with overpopulation. Think it through just a little more.


    • Ginny December 14, 2012 at 4:44 am

      The amount of garbage that each person produces is not on your list, but should be.


  • polistra December 9, 2012 at 7:20 am

    Very sensible article.

    We don’t need to make the choice. Nature will make the choice, as it does with all other critters. When people exceed the carrying capacity in one location, they starve and die.

    Until fairly recently, this basic lesson was understood everywhere, leading to appropriate feedback loops on reproduction.

    We’ve broken those loops in parts of Africa by providing endless food aid to countries that don’t have the sense to control their own population or organize their own agriculture. This enables them to reproduce even more and farm even less. Without the aid, those areas would either starve or improve.


    • Maria Warren December 12, 2012 at 12:56 pm

      @Polistra – Africa doesn’t have the sense to control it’s own population? Try that Africa was oppressed by other nations for hundreds of years and is still suffering as a result of that oppression and expoloitation. Rich nations are still plundering their land. Poverty and lack of education for children there is not their fault. Add to that – Religion – white missionaries spreading the word of Christ there all those years ago, and Popes since then and still today scaring them out of using contraception, no wonder there is such a large population.


  • scott December 9, 2012 at 10:23 am

    Too many people? Hard to say. Here are two interesting pieces of evidence.

    1) genius leaders.
    it is easy to say that if Steve Jobs did not exist, someone else would fill that role. But look at apple now, and observe. Each new individual is a chance. A roll of the dice. Rarely, you come up with a world-changing super leader. The more often you roll those dice, the more super-leaders you get. We need every one of them.

    2) population decline.
    7 billion now. in a dozen years, 9 billion. Maybe 11 billion, eventually. But maybe not. Human population growth is rapidly decreasing. If not in ten years, then certainly within forty, the world population is going to decrease.
    How will you feel when you watch the world population go from 6 billion to 4 billion? I can promise you, it will not be a feeling of relief.


    • Al Luongo December 10, 2012 at 6:36 pm

      1) genius leaders. Western civilization was invented in a city the size of Dubuque, Iowa, because of what Athens demanded of its people. Which is more likely–that Steve Jobs was so effective because there were a couple of hundred million Americans around when he was born, or because he had the opportunities in our society to fully actualize himself? I have no doubt that there is a Steve Jobs somewhere in an overpopulated country who will never be able to achieve anything close to his–or her!–full potential because of poverty and ignorance.

      2 population decline. Of course there will be problems when a population is declining, even if it is the result of rational choice and is totally voluntary. Social change is always problematic. But I believe the problems can be managed if we can get past our current economic and cultural superstitions. If it were arrived at equitably and voluntarily, a world of two billion people, even with our current knowledge of health, science, and technology, would be a paradise on earth. Maybe that’s what people are really afraid of!


  • Walter Borden December 9, 2012 at 12:46 pm

    This is another in a long line of oversimplifications by this author on this subject. Massive (net) biodiversity loss, ocean acidification, and the simple reality of the fact that when a pond is half full of algae that doubles each day after 10 days its totally full on day 11, show quite clearly that Dr. Karieva is more interested in making political points and providing rationales and cover for corporate benefactors than serious discussion of the issue. The world is not a river in the NW and cannot be viewed through the prism of errors made by conservationists viz. Salmon populations.

    It might feel intuitive and clever to point out that extinction is part of adaptation, but its a question of rates as well as degraded shared habitat. Replacement rate questions for populations in developed nations have no meaningful impact on population explosions in India, China and Africa. Simply because the west (and perhaps its the human condition) is too greedy to accept a slightly lower standard of living in order to bring vast swaths out of grinding poverty. Yet this is not in itself, a logical basis for asserting population growth.


    • Monte December 9, 2012 at 7:40 pm

      So, the world is a pond full of algae, but it is not a river in the NW, therefore the author is a corporate shill. I’m having trouble following this line of reasoning. Maybe I’m too greedy.


  • NYEngineer December 9, 2012 at 4:42 pm

    I agree. Both number and percentage of hungry people are lower than they were when the earth had 1/2 as many people. In the United States, air and water are much cleaner than they were 50 years ago. One hundred California SULEV cars emit less pollution (other than carbon dioxide) than one car from before the passage of the Clean Air Act. This has taken approximately 50 years to accomplish. Would it have taken 100 years with half as many scientists and engineers?

    Our society has turned against progress in every area. If we had retained the optimism of the 1960s and applied it to the problems we actually had (pollution, warfare, energy shortages, etc.) things would be going much better. Declinist solutions like financial manipulation, lowering standard of living, or stagnation of physical plant haven’t helped us much, and they are not going to.


    • Scotsman January 17, 2013 at 7:45 pm

      You make some bold assumptions. More people therefore means more scientists and engineers and progress?. Wouldn’t an optimal population produce higher quality people?. A well fed, well educated, healthy population could generate more results than a larger but less nurtured one.

      The question really is; is the population optimal?.

      Impossible to say, but low population high development usually go hand in hand. Australia, Norway to name a few. There are also far more factors to equate, are these countries developed because of location, exploitation of the larger less developed?. In other words, perhaps this occurs because they can take from the larger community to benefit theirs?.

      The whole question has too many factors to reliably come to a solution without some serious research.


  • Name Withheld December 9, 2012 at 9:15 pm

    This was unfortunately a weak, rambling, half-baked article in my opinion. It had a point in there somewhere, and it wasn’t necessarily incorrect.

    While we’re on this subject, here’s a point you don’t hear often enough. With 7 billion people on the planet, most of them living in industrialized urban areas, we’re like a bull in a china shop of the earth’s natural environment. Here are some examples.

    1. We don’t trust our tap water, so we all start drinking bottled water. So within only a few years, we have so many disintegrating plastic water bottle fragments in the Pacific Ocean that they can never be removed, killing bird species, and turning the ocean into what has been described as a “giant toilet bowl with no ability to flush”. So we switch away from bottled water in just a few years, but the damage is already done and cannot ever be cleaned up.

    2. To feed those 7 billion hungry omnivores, we have 2 billion cows on the planet, most of them in our industrialized agricultural systems. They require massive amounts of water and grain. They generate staggering amounts of waste, so much that it contributes more to global warming than our entire transportation system.

    3. To move our 7 billion people to and from their homes, workplaces, and shopping centers just so they can earn their paychecks and buy their groceries to stay alive, we require massive amounts of fossil fuel energy. Even though we have an impressive array of alternative energy technologies, only our fossil fuel sources are efficient enough to keep our systems from grinding to a halt and plunging billions into poverty and starvation.

    4. Whenever we consider switching technologies to address any of these wide-scale environmental and/or health effects, we generally look at a choice between “the frying pan and the fire”. If we make our homes and furniture for 7 billion people out of wood, we risk deforestation. If we make them out of plastics, we use up oil reserves.

    5. Our 7 billion people generate so much household waste that it cannot be handled. Some municipalities truck their trash hundreds of miles away. We can’t burn it – for the sake of air quality. So people begin to recycle – but our society doesn’t have the resources to sort all those used recyclables. So we ship it in boats and trucks to Mexico and India for them to pick through our trash piles looking for plastic bottles.

    Do you see what’s happening here? We have a never-ending series of unsolvable environmental and health problems…ALL STEMMING DIRECTLY FROM SUCH A HUGE POPULATION. If had only 1 billion people, all of these problems would be easier to handle. So we keep spinning our heads and scrambling to solve an ever-increasing slew of environmental problems…and few people see the underlying cause of them all. WE HAVE TOO MANY PEOPLE! That is the root of all of our environmental problems. There aren’t enough natural resources on the planet to solve all our problems. Nothing is sustainable about our society. We’re slipping down a slippery slope.


  • tom December 10, 2012 at 7:30 pm

    I largely agree with most of the criticisms directed at what I see as a pretty flawed article. My particular gripe is that I totally disagree with the writers blithe assumption that the Pleistocene megafauna was destroyed by humans. Did these humans hunt them? No doubt. Were they capable of of causing all these extinctions? I do not believe it and it is far from having been proven. Many, if not most of the vanished menagerie would not have been used as food by humans, and would have been too elusive, fierce and unrewarding to hunt. The idea that this vast array of species could have been wiped away over this enormous continent by the number of humans in existence at the time, most of whom probably lived in concentrated groups, using primitive weapons is totally unconvincing to me, even though I am aware of the propensity of humanity to destroy everything in sight and damn the consequences.


  • witkonamu December 10, 2012 at 8:07 pm

    When talking about population in relation to nations and how they factor into the problem our world faces, you should also take into account how certain nations or “people” produce waste or contribute to environmental destruction from their consumerism.

    Another thing to think about when talking about how congested areas such as cities have hosted some of the best ideas to help counter problems humanity has faced, these places have mainly developed ideas, tools, or societies which only look to help us as people thrive, instead of everything else around us. They also have disconnected people from the land, ocean, or both, in which they live in. It doesn’t take much to see this, look at most local organic farms and how they do nothing to grow native foods found in their area.

    Although the human population may be unbalanced with what the world can take care of, there is no reason why we should look to all other humans as the problem, instead we should be looking at how humans and the spherical habitats we live in can work hand in hand to keep our future from becoming a chaotic destructive painful experience for our grandchildren.


  • Andy Brower December 11, 2012 at 8:17 am

    Ahh, the liberal who is so open-minded he disagrees with his own opinion. An excellent recipe for doing nothing. Solving this problem starts at home: if you are committed to your belief that there are too many people in the world, then don’t have any children. And tell other people that you don’t have any children because you think there are too many people in the world. Sacrificing your fitness for the good of other species may not be a sound evolutionary strategy, but at least it shows you are sincere.


    • Anonymous C February 5, 2013 at 6:26 pm

      Actually,there is a well known concept that shows animal behavior that serves overall fitness of a population. It’s termed ‘indirect fitness’ or ‘kin selection’. Kin selection occurs when an animal engages in self-sacrificial behavior that benefits the genetic fitness of its relatives-


  • Rob Moir December 11, 2012 at 11:48 am

    To answer the question are there too many people on the planet is not science, it is an act of faith. So is placing too much believe and dogma into one’s projections and hypothesis, despite the quality of the science and history informing. The authors of the Population Bomb convinced people not to have children to save the world – they were wrong. Climate change and ocean pollution is not the result of too many people. It is the result of too many Americans where we are 4% of the world population and responsible for 20% of the carbon pollution in the atmosphere causing climate change. Bangladesh is heavily populated and it is feeding and watering its own people. Population is often more the solution. Under-populated communities pollute disproportionately more. The question is a very American one that follows on our belief in Manifest Destiny – like that’s a fact. Excellent article, Good for this scientist to point out when the Emperor is wearing no clothes.


  • tom December 11, 2012 at 6:47 pm

    Interesting points of view, although how anyone could seriously argue that we do not have “too many” Steppe Apes baffles me. At this point the only thing that might save the biosphere, is the immediate demise of most of us, something that probably will not happen,…not in time anyway.


  • Arthur Noll December 12, 2012 at 11:16 pm

    Soil is eroding from agriculture in the US at an estimated rate of about 5-7 tons per acre per year. That is low compared to many other countries, and yet it is far above natural soil formation. We maintain fertility of soil that hasn’t yet eroded with finite fossil fuels as both feedstock and energy to make nitrogen components, and as energy to mine, refine, and transport other components. Phosphorus in particular is being depleted, other plant nutrients are in bigger, more common deposits, but when the energy to mine, refine and transport is also fading, this is of little help. This dependency on synthetic fertilizer is virtually world wide, soils everywhere have been depleted, and erosion is also a world wide problem. Salting of soil is also a problem. We are also dependent on these same finite fuels to transport food long distances, and to store it, and cook it. Billions depend on fossil fuel to maintain and run sewerage systems, to have clean water.

    Growing annual crops repeatedly, as we are dependent on doing, has inherent problems with erosion and depleting fertility. Annual plants have no root system to begin, a relatively small one at the peak of growth, and then it dies and rots again. The size of the root system is what enables a plant to be good at recycling nutrients, to grow large amounts of vegetation that both living and dead protects the soil from impact erosion, makes humus that soaks up rain and stops fast runoff that causes gullying erosion. Perennial grasses and trees grow large, dense root systems that hold soil, recycle and trap nutrients with the greatest efficiency. Killing these to grow annual crops gives large initial crops but erosion and depletion problems start quickly.

    The monocropping of annuals done for greater efficiency in planting and harvesting, is also vulnerable to insects and diseases. This has led to an arms race as pesticides are used that insects and diseases evolve immunity to, and it is not at all sure we can continue to win this war, especially as the energy we need for the industrial operations of making pesticides dwindles. This problem of disease evolving immunity to present controls, is also a serious threat to the large human population that is much like a monoculture of plants.

    Monetary systems are grossly inefficient at producing cooperation, as they inherently make people into independent agents. They also drive unsustainable use of resources, because players can win market competitions by ignoring sustainable use of resources. Yet most people cannot comprehend the possiblity of changing to a different system operating on more objective measures of value using energy and sustainability. They hold to what they have been taught as children.

    And with that it is very common that people hold to mystical beliefs about future resources, and/ or have superstitious belief in their expectation that since things have sometimes been found in the past to solve problems, that they will always be found. There is no relationship between what has been found in the past and what might be found in the future. Many past civilizations did not find what they needed. Superstition is not a wise thing to base future expectations on.

    And of course a very common thing in our history, of people fighting wars on expectation that their culture is superior and should expand or have more of scarce resources, regardless of their culture based on mysticism, superstition, just as other cultures they fight with, does not bode well for our future, either. The world trade that billions are dependent on for food, fertilizer, fuel, machine parts, is vulnerable to being crippled by war.

    Who should die? People with superstitious, mystical beliefs, refusing to give them up, eventually run into reality, run into each other, and destroy themselves. People with a bit more sanity deal objectively with reality and have far greater odds of survival. We are not behaving any differently from any other species that overshoots resources and has a dieoff.


    • Rob Moir December 13, 2012 at 9:06 am

      Thinking there is an overpopulation problem is a superstitious, mystical belief foisted on people to avoid addressing the real problems brought on by people’s misbehavior. It’s a chimera used an excuse for doing nothing to correct the real problem.


      • Daniel Kroner December 15, 2012 at 6:36 pm

        No, population size is a fundamental part of all of the concerning issues. When you consider the quality of life issue Mr. Kareiva barely touches upon in greater detail you realize that there are billions of people that are living below what any reasonable person would consider a minimally acceptable standard quality of life. To raise their quality of life issue is going to require a large increase in consumption than can possibly be hoped to be reduced in populations that are over consuming. So yea, population size is a fundamental problem.

        Read more in the link posted in my other comment.

  • Daniel Kroner December 15, 2012 at 6:32 pm

    This article is ridiculous. It spends the first half arguing against the second half then claims that population size is not the real question while not going into the quality of life issues at all.

    Not to mention the fact that quality of life issues are intractably a part of population size issues. Raising quality of life in the areas that need it the most will require absurd numbers of people using more resources. Population size can not be ignored as a major contributing factor to a lot of our issues and pretending its not, even for half of an article, is irresponsible.

    More here:


  • Lee Miller December 24, 2012 at 5:32 pm

    Ken Boulding had this figured out over 50 years ago and here we are still arguing about the obvious. Who will applaud when population declines? I will, but since I am an old guy I likely won’t get to see it. We are definitely one evolutionary fluke too many!

    Conservationist’s Lament
    By Kenneth Boulding
    In: Man’s Role in Changing the Face of the Earth, 1956
    University of Chicago Press, p. 1087

    The world is finite, resources are scarce,
    Things are bad and will be worse.
    Coal is burned and gas exploded,
    Forests cut and soils eroded.
    Wells are dry and air’s polluted,
    Dust is blowing, trees uprooted,
    Oil is going, ores depleted,
    Drains receive what is excreted.
    Land is sinking, seas are rising,
    Man is far too enterprising,
    Fire will rage with Man to fan it,
    Soon we’ll have a plundered planet.
    People breed like fertile rabbits,
    People have disgusting habits.

    Moral: The evolutionary plan went astray by evolving Man.


  • Jack Marshall December 26, 2012 at 11:49 am

    Here’s a note I just sent to Mark Tercek, President and Chief Executive Officer of the
    The Nature Conservancy:

    Dear Mr. Tercek,

    Having just read Peter Kareiva’s “Are there too many people on the planet?” I’m writing to let you know that after years of modest contributions to The Nature Conservancy I will no longer support your organization.

    Kareiva’s article resorts to silly, superficial straw man arguments that are unworthy of a highly regarded (and recent NAS inducted) scientist ”responsible for developing and helping to implement science-based conservation throughout [The Nature Conservancy].” With a rhetorical wave of his hand, he dismisses or neglects convincing evidence that the earth’s carrying capacity is indeed overstretched in many regards, and chooses to avoid the fact that as populations expand current environmental problems will certainly be exacerbated by growing demands for consumption (and the resultant pollution) in much of the world.

    No thoughtful scientist suggests that population size alone is responsible for the world’s array of ecological threats. On the other hand, no responsible scientist should disregard population growth as a root cause of such problems. Kareiva’s cornucopian reliance on human ingenuity alone (somehow finding realistic new answers for “the kinds of settlements and economies we have built”) is, as I think he must know, unwarranted.

    And asking “Who should be eliminated?” smacks of the kinds of cheap shot one expects of climate change deniers. Observing that “new patents and inventions overwhelmingly come from cities-and the larger the city, the more patents and inventions are produced,” has nothing to do with populations’ impacts on natural systems; rather, the statement suggests little more than wishful thinking about a miracle solution.

    The Nature Conservancy’s senior scientist has apparently succumbed—like the Sierra Club before it—to what I imagine is political pressure to deny the role of population growth in finding ways “to conserve the lands and waters on which all life depends” (TNC’s mission statement).

    With disappointment,

    John F. (Jack) Marshall, Ph.D.
    Advocates for a Sustainable Albemarle Population (ASAP)


  • Ron December 27, 2012 at 8:58 pm

    The writer’s arguments make no sense. For example, he says “simply [huh?] by planting half the U.S. area with eucalyptus, we could change the current total human footprint from 1.5 Earths to only one Earth” and offers this statement as his “simplest” proof that our footprint is CURRENTLY not 1.5 Earths. But in saying that, he has just admitted that unless we do that (which of course we never will), we are in fact CURRENTLY using 1.5 Earths! The hypothetical “fact” he gives in no way refutes the ecological footprint calculation method; instead he offers a scheme, and a completely infeasible one at that, for getting our footprint back down to one Earth. Furthermore, while planting vast quantities of non-native trees in the US that would, if they survive, sequester lots of CO2 might make Earth’s carbon footprint sustainable, it would not address any of our other environmental crises, many of which are helpfully listed by Dave Gardner above, not to mention the effects of disrupting our native forest ecosystems. He has apparently confused the CARBON footprint with the ECOLOGICAL footprint. The writer’s other argument against ecological footprint analysis is that it is “deeply flawed and has been widely critiqued in the literature” followed by two references. He doesn’t bother to say what those two papers found to be the deep flaws in EF, so I won’t bother to identify the flaws in those two articles. However, I will note that EF, painstakingly developed and continuously improved over the last 20 years by many researchers, is by far the most widely accepted methodology in the scientific community for measuring humanity’s overall impact on the natural world, whereas the writer does not identify any alternatives at all. The peer-reviewed journal “Ecological Economics” from which he has selected his two sources has published 2,345 articles on EF, so he has selected 0.09% of this one journal’s articles to indicate that EF has been “widely” critiqued. The EF organization’s website lists 120 peer-reviewed academic papers about EF. One of its creators, Dr. Wackernagel, recently received the Boulding Prize, the highest honor in ecological economics, from the International Society for Ecological Economics. The current EF calculation method paper was recently accepted for publication by the peer-reviewed journal “Ecological Indicators.” The EU’s European Commission says “The Ecological Footprint is a useful indicator for assessing progress on the EU’s Resource Strategy and is unique among the 13 indicators reviewed in this study in its ability to relate resource use to the concept of carrying capacity.” I think the evidence is overwhelming that the writer is wrong about EF.

    The writer proceeds to make an absurd comparison of the current and ongoing massive global species extinction, obviously caused by humans (largely due to habitat destruction to make room for ever more people), to the extinction of a relatively few large terrestrial mammal species thousands of years ago, which some have conjectured was caused by human over-hunting (but quite possibly not, as clearly explained by tom above). Regarding large terrestrial mammal species, there has never been anywhere near seven billion members of one such species on Earth before. The writer does not give any scientific evidence to believe that Earth’s ecosystems will continue to support that many.

    Finally, as pointed out most effectively by Daniel Kroner above, the writer doesn’t understand that carrying capacity from a policy perspective is not merely the maximum number of humans supportable at a subsistence level, perhaps queuing up to be fed bread, tofu, and vegetables every day by a caretaker / dictator bureaucracy, but is instead the maximum number of humans that can be supported at a humane standard of living, with the freedom to eat meat, drink wine, play, travel, study, enjoy music and art, and engage in democratic self-governance if so desired. This number is what the the ecologist Garrett Hardin called “cultural carrying capacity” and will always be much less than biological carrying capacity. The writer ignores the fact that total impact equals impact per person times population size, and people will refuse to minimize their impact.

    In summary, the only thing the writer has proven is that he is illogical and without scientific understanding on issues of human overpopulation.


  • Ron December 28, 2012 at 1:02 pm

    I recommend reading Daniel Kroner’s blog post linked above for an excellent analysis of one of the major flaws in this article. As shown in the graph he has posted there, in 2007, the average human’s quality of life, as measured by the UN’s Human Development Index (HDI) across all nations in the world, is strongly correlated to per capita consumption, as measured by the ecological footprint of consumption (EFC). Fitting a straight line to the data results in a coefficient of determination (R squared) of 0.57, which indicates a fairly strong linear correlation between HDI and EFC. Fitting a logarithmic line results in an even higher R2 of 0.67. While the UN has set a somewhat arbitrary target HDI of 0.8 for all countries to achieve, a look at this graph shows a point of diminishing returns on increasing EFC at an HDI of about 0.9. This accords with the commonsense idea that our quality of life depends on our consumption of resources, up to some point of diminishing returns. In 2007, eight countries had an HDI of at least 0.9, and of those the one with the lowest EFC, at 4.9, was New Zealand, which I understand is a lovely place BTW. At an EFC of 4.9 global hectares per capita and a world biocapacity in 2007 of 11.9 billion global hectares, 2.4 billion people could have been sustainably supported. So now the writer has a logical, scientific answer to his question: Yes, there are too many people on the planet, probably by a factor of over two.


  • Overpopulation: More Myth Than Science? | Lafeber Conservation and Wildlife January 2, 2013 at 3:16 pm

    […] Even today the overall impact of humans on the earth is debatable. For instance, calculations for ecological footprints that resulted in the widely quoted number that we are already using up one and half times what the earth can sustain has been found to be flawed. […]


    • Ron January 7, 2013 at 6:29 pm

      This is an excerpt from the commenter’s own blog posting, which links back to the article above as the source. What a pristine circle, untouched by human thought! Meanwhile, the commenter has no rebuttal to the overwhelming evidence to the contrary that I provided above.

      Following up on my last analysis above: In case you’re wondering how many people could have been sustainably supported in the US at an HDI of 0.9 in 2007, if they had had an EFC of 4.9 instead of their actual EFC of 8.0, the biocapacity of the US was 1,194 million global hectares, so 244 million Americans could have been sustainably supported. And remember, that’s assuming that per person consumption had been 39% lower than it actually was. So given that the actual US population is 315 million, it follows that there are also too many people in America, probably by over 20 percent. I suggest that this fact is at least as relevant to us Americans as the fact that the planet has too many people, because, unlike the planet, the US is a sovereign country and thus is the only entity with the power to make and enforce policies within its borders that would achieve a sustainable population size. We do not need to persuade any other country or the UN to address the world’s overpopulation problem in order for us to address ours. In fact, we would be much more persuasive if we started with our own country first.


  • Chad January 5, 2013 at 2:06 pm

    Nobody gets it, because nobody is intelligent or as studied as need be to “get it”. Usury = Industrialization = Population-growth. It’s a cycle, and if it stops, (most) everybody dies. It’s a system of endless plunder of humanity and the environment to pay the unprinted interest from usury. There is no other way than plunder (wealth for free). And every technology that is instituted to solve a problem is laid to waste by the increasing population required to pay off debts from previous generations of the usury systems. And if we eliminate any part of the cycle, it all crashes, and we are instantaneously back to the agrarian age, or earlier, and most people die. We are heroin junkies that will die without our next fix, so we can’t stop. We are cannibals lusting in the conquests of our plunder, not realizing that soon, the only dinner left for our plates will be ourselves. We are idiots supreme.


  • Chad January 5, 2013 at 2:17 pm

    Solution? Everybody always wants the solution amidst the cries of a problem. Well, here it is:

    Put a small dot tattoo on the bottom of the big toe each time a woman gives birth. When a birth occurs with a dot on the bottom of each big toe, tubes tied. END OF ALL MAJOR PROBLEMS FACING HUMANITY. Do-able and simple. No need to be Nazi-like about it, just make it part of all hospital birthing policy as a national emergency measure or whatever. No need for databases or other infringements of liberties. No need to hunt or chase down violaters. We can then let things spiral back into control without any major catastrophe or asking “who lives and who dies?” But no, nobody wants to hear it, it’s too ‘inhumane’ or something – I don’t know, what is the real reason people would oppose a measure such as this, and how could any such opposition compare to the catastrophies humanity faces otherwise? Please, do answer.


    • Anastasia July 4, 2015 at 11:28 pm

      Great solution! My husband and I have two children, soon to be top contributors. We willingly stopped at two. Both of our sons are in the top 1% academically in the country and they are both deeply concerned about the environment and sustainablility. I encourage them to use their brain power and apply it toward this mess humanity has gotten itself into. I am going to sound arrogant when I say this but I wish more folks took a cue from me and my husband. We both planned our lives out carefully and logically and refused to be driven by base urges and what feels good in the moment. We planned everything and have been able to raise our children with a high standard of living and provide them with the best education. We have raised them to be in a mindset where they need to contribute to solving the world’s problems and not adding to them. We have raised them to tread lightly and resist the urge to be part of the American Sheeple. We need less sheep and more thinkers.


  • Tom Bombadil March 19, 2013 at 9:46 am

    I’m not even going to be sophisticated in my reply here –
    You are wrong if you do not recognize overpopulation as the root cause of the vast majority of all the worlds problems.
    Almost everything can be traced back to there being too much of something for something else to handle.
    The basic formula is this – Humans, in their insimplicity, are a burden on the planet. More humans = larger burden. Larger burden = more difficult to carry.


  • Art Schultz March 29, 2013 at 11:59 am

    Gee, the only thing I learned from reading this entire post is that even experts in the field don’t agree on anything related to the population question. I have a PhD in science too. Guess I’ll just keep flowing down that ole river of time and see what happens. Many thanks for all your ideas….


  • Greenie Guest March 29, 2013 at 6:06 pm

    There is nothing wrong with the author of this article basically saying “for a quality day-to-day life, lower density of humans is better”. It is likes rats: Do you like 2,000 rats in a cage or 150.
    The answer is quite obvious and humanity needs to wake up and realize that by NOT restricting our numbers we all suffer. (All it will take is: 2 child max per couple, use of birth control, continuing abortion access, and at the end of life a policy of NOT treating the elderly for conditions they will end up passing away from anyway.)
    What is sweet about planning all of this now is that future generations will have a better quality of life on earth. That is a admirable gift to think about. (Not to mention the plight of animals, fish, birds, and other life forms who share this globe.)


    • Art Schultz March 31, 2013 at 1:40 pm

      Dear Greenie Guest, Your answer that “humanity needs to wake up and realize”…etc., etc, is amazingly naive. This is never going to happen. Humanity is a huge seething mass of ego-centric animals just trying to satisfy instinctual desires. Mother nature, i.e. natural selection, will determine what eventually happens to our species, not us. Go enjoy the years you have left, hold your family and friends close, and forget about humanity.


      • Anastasia July 4, 2015 at 11:00 pm

        I agree with you 100%, Art. You have it right. Most of humanity is just trying to fill instinctual desires and not contribute. The only group(s) of people I know of on this planet that have a vision to overcome urges and add good to the world are earnestly practicing Jews as well as Buddhists. I pretty much write off everyone else as a waste of space.

  • John Bear April 23, 2013 at 1:08 am

    The concluding statement si… “The right questions are: What quality of life do we want all people on the planet to share? And how can we achieve that quality of life while preserving as many species and ecosystems as possible?”. is all that needs to be said.
    I would add to the question “what quality of life?” by saying that it should be as good as I would expect for myself and that we have no certainty that the earth is not the only place where life exists and therefore no matter what your persuasion any claim oof morality is unsustainable if you do not try to give space to all life.


    • Ron April 28, 2013 at 2:40 pm

      Please read my analysis above for scientific answers to the two questions. To summarize:
      1. We want all people on the planet to share a quality of life as high as that achieved by the most advanced nations currently. Taking HDI as a widely accepted metric of quality of life, that would mean an HDI of at least 0.9.
      2. We can achieve that quality of life while preserving as many species and ecosystems as possible by reducing our environmental impact to no more than what ecologists and other scientists have estimated as the capacity of the earth to absorb that impact without irreversible damage, such as loss of species and ecosystems. Taking EF as a widely accepted metric of our environmental impact and biocapacity as a widely accepted metric of the earth’s absorptive capacity, both measured in global hectares as of 2007, that would mean reducing the earth’s human population to no more than 2.4 billion people so that all could live at an HDI of 0.9. In the US, in order for Americans to live sustainably within the nation’s biocapacity at an HDI of 0.9, that would mean the average American reducing consumption by 39% and the nation reducing its human population to no more than 244 million Americans.


  • David - Ireland July 29, 2013 at 8:31 pm

    Yes, I had this thought a while back and in the last couple of days it arose again this is how I just found this article. I was researching soil mineral content against levels of disease, especially selenium content, I just read a university research paper, its happening to the animals as well, as the earth begins to purge the population because we have essentially purged the earth and the minerals in its soil, I believe we are well past a sustainable population, the incidence of cancer in Ireland is now expected to be 1 in 3. All my grandparents lived into there 90`s never had cancer. Farmers are also using unbelievable chemical methods to force maturation of crops, ie. a common agricultural broad-spectrum systemic herbicide of questionable safety claims.


  • Curt January 12, 2015 at 1:02 pm

    I’m surprised. Why is it that if there is a reduction in the population it requires selection. There is plenty of diversity to go around with say 6,000,000,000 people. Dealing with our developmentally disabled makes us human. Preventing the poisoning of our waters that lead to such health issues also makes us human. It takes the general population to accept the fact one or two children are enough. Will this notion catch on in my lifetime. More likely God will return to earth. One thing I have learned about history is mankind does not learn from history.
    We won’t respond to the treat of famine we will only respond to famine.


  • Matthew January 28, 2015 at 1:45 am

    Now you cannot say that there aren’t too many people. saying that people need to be removed makes you sound like Hitler. Although “removing” , in a sense is all there is to do. When I say remove I don’t mean put a bullet in their head. People need to be aware that the population number is far to great. When I say people I mean everybody. If people are simply okay with destroying the earth and continue down the path of overpopulation then by all means they can simply let it fade into whatever messed up world that will go into. However, if there is an action put forth that can make an effort to bring awareness to overpopulation that would be the route to go. If people were aware of an effort that they can give and a so called “sacrifice” for humanity then they would be helping humanity. By volunteering to not have children or to have a vasectomy or have her tubes tied they would be able to help the population. Now it’s strictly only by volunteering. Not some crazy dictatorship here. I understand each humans instinct to survive and sow their oats and make children but that is just the thing that is causing overpopulation! If we have 7billion+ people now and they’re almost ALL trying to have children and do what they want then the number will continue to rise! It will eventually be 15billion+ or maybe more! All because almost EVERY single human being desires sex and children eventually…even I have that desire but the earth being destroyed and overrun by human beings is far more terrifying than not having children. Just my opinion.


  • Arran February 5, 2015 at 5:38 pm

    Maybe we could start with….. Hmm it does seem like there are a lot of places to start. Well why not at the top at those who are not starving, for anything. Not food, they have any thing they want, FRESH too, unprocessed and prepared healthfully and deliciously! Not water, that stuff runs out of the ground, plus they have filters that make it “positively alive” lol see what happens did there for those who know about water! Oh! And, first and foremost they do not starve for knowledge being the he most valuable. So before thinking about how to fight overpopulation, think about why would 99 horses be better than one horse pulling a wagon? Then think if everyone knows that we are in control shouldn’t we hide our identities? Then go into history if you trust it and look at The practice of burning books to insert and teach from there own prescribed knowledges and laws! Now why would a species that is unraveling the universe little bit little “apparently” be starving? We can fly, swim, survive exteme pr assures and temperature, I mean we learned to cook when we were starving last time I would think! But, now we ar starving or dying of obesity? I believe if the powers that be wanted change there would be change! Stop watching the right hand when they are e left hand is behind there back! Guess what! There left handed too! They might even have a third hand they have us so fixated on these “consequences” if you work hard though and listen well “reward”! Over population is an awesome people tool, I mean it keeps them fed all of the smart and or caring people busy and it’s free! Why can’t a concept in a book “1984” be a rational conclusion for the mess of today? Oh! They did let it be published….but only as fiction. Lol have faith in what you know because what you know might only BE faith, hahahaha!


  • Are There Too Many People on the Planet? May 8, 2015 at 8:16 pm

    […] Kareiva recently published a disjointed article on the topic of population size on The article appears to be a poor attempt to dismantle a position he admits to holding himself. Dr. […]


  • Anastasia July 4, 2015 at 10:50 pm

    Okay, I am going to say it clearly and not be embarrassed about it. The world has too many people. The third world is responsible for this population explosion. I say force them to take birth control and close our borders in the Western world so that the third world cannot flood in. Next, pass laws where you have to have a license to have children. To get a license you need a thorough psychological exam and also need to be able to show that you can afford to feed, clothe, and educate your children. Having children is not your right or anyone’s right unless you/they can provide for them without state assistance. My husband and I waited to get married and to have children after our educations were finished and after each of us had high paying careers. You may find my comments about overpopulation unkind, but I can assure you we have children who will be future contributors and innovators who will hopefully help put the world back in order once the environment is devastated. We need more people like my kids who are poised to solve the world’s problems and less people who are “useless eaters”. Otherwise we are all going to be in big trouble.


  • Ram Dass September 21, 2015 at 11:14 pm

    Who can breed and who can’t? Anybody can breed, but if you can’t feed ’em, don’t breed ’em. What happened to survival of the fittest? We are quickly becoming a welfare planet, not welfare State, Planet. We have people living in unsustainable areas that have no clean water or food to eat. What do we do? Give them this things? Really? 10,000 children die of starvation every day? I bet if you stop feeding them, they’ll stop reproducing having more starving children. And let’s not forget every dope smoking crackhead that deserves welfare so that they can pass on their genes into an already weakened gene pool.


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