Earth Needs Renewed Attention to Human Population Growth

Note: The article below, which appeared recently in a number of online publications, was written for a general audience. It should nevertheless be of interest to GIM readers as an effort to spread awareness of the population issue and to dispel a couple of the many erroneous notions surrounding this controversial topic. This version contains a small revision or two but is largely the same as the version which first appeared at Online Journal.

Continued study of our global ecological challenge has meant for me a gradual evolution in my thinking about its dynamics. Population stabilization and reduction are arguably the single most powerful and cost effective means of moving toward ecological sustainability. Yet in just the few months since I wrote this article I’ve become increasingly concerned about the possibility that we’ve missed our chance to avert collapse. (See, for example, in my introduction to Ken Smail’s article on population reduction, Ken’s comment concerning the “temporal problem” with which we’re faced. Or for a detailed discussion, see Paul Chefurka’s analysis of the relationship between energy depletion and population. [10/21/07 – Edit: Note, however, Paul’s reassessment of some of the basis of his analysis.] Or see Jason Godesky’s argument that collapse is inevitable.) If so, reducing fertility rates would serve not as a solution per se, but as a means of softening the landing by sparing future lives. It remains, in any event, the most effective, sensible, humane response to our ecological crisis. — JF


Concern over US population sizeBy John Feeney:

There’s a simple theme in today’s environmental writing. It shows up in titles like “Cut Your Consumption by Switching to Fluorescent Light Bulbs,” “Lawmakers Developing Fuel Economy Plan,” and “Is Wind Power Right for You?”

The trend is to promote reduced personal resource consumption. And it’s a crucial part of the solution to our energy and ecological woes.

But it’s only half the solution. The other half has faded from prominence in recent years. It’s the need to end global population growth. At a time when scientists tell us we’ve outgrown our earth, it deserves our renewed attention.

Population growth received a good deal of press in the 1960s and 1970s, but since then it’s become a taboo subject. China’s draconian one child policy and political pressure from social justice groups who saw the population issue as a distraction from their preferred causes saw to that. Indeed, some writers today even question the contribution of population growth to ecological degradation.

Was attention to population a mistake?

Are they right? Was past attention to population misplaced? Was it overblown as a root cause of environmental problems? Does it even compare with consumption rates in its environmental impact? Fortunately, a simple, unassailable equation answers these questions. Appearing over a decade ago in an article by John Holdren, recent president of the American Association for the Advancement of Science, it’s rarely mentioned in today’s environmental debates. Yet it shows us precisely what determines our total energy consumption.

In plain English, it says total energy consumption, for a country or the world, equals population size times the average per capita energy use. So if E = total energy use, P = population size, and e = energy use per capita, we can say E = P x e. [1]

There is no getting around that simple math. It means we have little chance of tackling our energy and environmental challenges if we ignore either of the two factors, per capita consumption and population.

In fact, though few environmentalists appear to realize it, today’s well known “ecological footprint” measure is an elaboration of Holdren’s equation. As the experts on the Global Footprint Network describe it, “Resource demand (Ecological Footprint) for the world as a whole is the product of population times per capita consumption, and reflects both the level of consumption and the efficiency with which resources are turned into consumption products.”

Hasn’t consumption grown faster?

But sometimes someone points out that in the last half century global and national resource consumption rates have increased faster than population numbers. The implication is that the rate of consumption is the more important factor, and the one deserving more attention. Is that correct?

The equation above shows the flaw in such a notion. Comparing population growth to the growth in total energy or resource use is to compare one factor in the equation to the product. Naturally, we would expect the product generally to be larger. To determine which variable is the greater contributor to our environmental problem, we must compare the two factors. The product, after all, is the problem. When we compare the factors, as Holdren did, we find population and per capita consumption both contribute heavily to total consumption.

But aren’t individual consumption rates much higher in some countries?

Still, there’s the observation that per capita consumption rates are much higher in developed countries. In the US, for instance, per capita consumption of most resources is many times higher than is seen in developing countries. Does this mean we should ignore population and focus only on reducing per person consumption? Not at all. Holdren’s equation tells us it’s never wise to ignore either population or per person consumption. It is precisely because the impact of US population growth is magnified by our high consumption rates per capita that some experts call the US population problem the worst in the world. With regard to oil use, for example, at current per person consumption levels, adding one person to the US population is like adding about 15 in China. In that light, ignoring population growth in the US is perilous.

And the discussion of population growth in the US need not become fixated on divisive controversies concerning immigration policy. On a general level, the key is to achieve widespread awareness and acknowledgment of the need to halt and then reverse our population growth. Specific solutions include social programs to reduce the number of unplanned pregnancies, thereby lowering fertility rates to the sub-replacement levels seen in other developed countries, and cooperative assistance to Mexico, for example, to improve its citizens’ economic opportunities so they’re not forced to come to the U.S. to earn even a subsistence wage.

Nor can we ignore population growth in developing countries. Fertility rates in many countries remain high, and projections have the global population, which has doubled since the 1960s, increasing by another 40 percent or more by mid-century. While it’s true per capita consumption levels in the developing world are today much lower than those in the industrialized world, they’re growing fast, in line with economic growth. We need only look at Holdren’s equation to see that without renewed attention to population, rising per capita consumption multiplied by already large and growing populations puts the Third World on a course toward disaster.

We in the industrialized world can hardly begrudge developing countries their rise toward Western living standards. We can, however, assist them in the transition to renewable energy sources. We can also assist with humane programs to hasten lowering fertility rates. Research and expert consensus tells us such programs should aim to improve the status of women. They need to increase girls’ educational opportunities, and women’s economic and health care options. They must increase family planning services and improve child survival rates. Such changes give women the social and economic freedom to opt for fewer children.

Having overshot the earth’s capacity to sustain our current numbers, living as we do, we must act now to avert catastrophe. We’ve depleted resources such as oil and groundwater and have damaged the global ecosystem, triggering a wave of extinctions. We’re dismantling the web of life. A growing number of analysts warn that if we fail to reduce both per capita consumption and to halt the growth of our population no new technology will prevent an unimaginable loss of life. The poorest countries will be the most vulnerable. We in the developed world, with the resources to act on these needs, have a moral imperative to do so.

[1] “E = P x e” is a precursor to I = PAT a better known, slightly more complex equation measuring environmental impact. See the relevant Wikipedia entry for a brief summary.
Image source: jtown’s photostream,, posted under a Creative Commons Attribution-Noncommercial 2.0 Generic license

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35 responses to “Earth Needs Renewed Attention to Human Population Growth

  1. We’re dismantling the web of life.

    To me that’s the key idea. Yet, while there is increasing acknowledgement of increasing carbon emissions and the bad effect they have on the biosphere, there is still too much resistance of the form, “we will change our ways as long as it does not impact economic growth.”

    Thing is, what if economic growth kills the web of life? It’s like a man in a burning house saying he’ll put out the fire only if his office is preserved. If you can’t guarantee the office preservation he’s unwilling to help put the fire out.

  2. What I’m reacting to, perhaps too hyperbolically, is statements from the Bush administration (from GWB himself) of the form “we will address climate change if and only if it doesn’t impact economic growth.” That’s like saying I’ll stop beating my wife if she agrees that the beating is good for her. It’s economic growth — as we know it today — that’s killing us.

    One can image a different kind of economy that doesn’t destroy the planet but there is no venue to discuss it.

  3. Yes, definitively yes.

    Perhaps the human predicament that appears darkly visible on the far horizon calls out for hyperbole or something else which serves to raise awareness of people who are still sleeping or else not yet sufficiently awake to see what is soon to become actually present.

  4. Fearlessly and self-righteously, the leaders in my not-so-great generation have taken hold of their responsibilities in such woefully inadequate ways and been found so grossly derelict in the perfomance of their duties that what we are seeing in the offing is a nightmare of catastrophic porportions for our children.

    Rather than acknowledge real challenges, our leaders avoid them at every turn in the road. The current leadership is intelligent, no doubt about that, but intelligence has not helped because this group of self-proclaimed masters of the universe are adamantly and relentlessly engaged in one fool’s errand after another.

    These leaders are actively mortgaging and threatening the future of those they claim to protect. One day our children may look back in anger and utter disbelief at so much of what the leading elders in our time have done, failed to do, and chose to gallantly describe to the children as “leaders exercising their many virtues.”

  5. Trinifar,

    Yep, there’s no healing the earth as long as we have insistence on economic growth.

    And dealing with population growth is an uphill battle as long as the powers that be tie it to economic growth.

    I have no doubt the next administration in the US will be an improvement, but I must say I see little in the way of serious steps to halt the current ecological decline in any of the candidates’ comments. I hope some of them are simply holding back on discussing more radical measures they might have in mind out of concern that such talk would make them unelectable. Perhaps someone will surprise us once s/he is in office. I doubt it though.

    I wonder if someone could get the next president to see the film “What a way to go.”

  6. Steve,

    Rather than acknowledge real challenges, our leaders avoid them at every turn in the road.

    That really does seem to be the pattern. You can almost predict where their attention will go. Identify the most profound problems of all, then look away from those to other, less significant problems. Those are where they’ll be putting their focus. It gets both absurd and scary.

  7. Just a quick correction to fix a broken link in the introduction above. My new, detailed analysis of energy and population is at

    The new paper is built on a quantitative model (called WEAP), which takes into account energy production from different sources, global per-capita energy consumption, and the effects of current and future ecological damage. The paper contains a lot less hand-waving than my original attempt in “Elephant in the Room”, and is much more defensible.

    And yes, fertility reduction and knowledge retention projects are where I think we should be putting our time, effort and money. We won’t be able to stop the train wreck, but we should do everything we can to reduce the number of people who are born in the middle of it. Knowledge retention projects might be analogous to leaving a first aid book at the side of the tracks, so the survivors who crawl out of the smoking wreckage will have some idea of what to do next.

  8. Heh, Paul, I had discovered and was fixing the broken link at the very moment you posted your comment. 🙂

    I would strongly urge everyone to read Paul’s WEAP paper. I haven’t read everything out there, but I’ve certainly seen no better analysis of the how peak energy will likely play out and impact human numbers.

  9. Nothing really new here, but it’s always nice to see these points well-articulated:,,2165698,00.html

    Is it just me, or is this topic beginning to get more attention?

  10. It does seem to be getting more attention, Dave.

    It would sure be nice if everyone’s efforts could bring about awareness of peak oil/climate change/species extinction/population issues before their convergence starts to be undeniable somewhere not so far down the road.

  11. Dear John,

    I agree with you completely. At least to me, the “powers that be” know more than they are willing to express with regard to the human predicament that is looming before humanity in the offing. That many too many politicians, economists and business people thoughtlessly support a soon to become unsustainable global enterprise of endless business expansion, is not difficult to understand. We can expect such behavior from those who have so clearly pledged their primary allegiance and reverent devotion to the success of economic globalization, regardless of the potential for eventual catastrophe that such a reckless and unrealistic pursuit portends. On the other hand, for scientists and demographers, who claim expertise in the science related to the human population, to stubbornly collude with the “powers that be” by remaining consciously and willfully blind, hysterically deaf and electively mute in the face of good scientific evidence of human-forced ecological collapse is incomprehensible.

    What worries me is this: our children will unexpectedly and suddenly come face to face with converging global challenges because their elders have remained adamantly and relentlessly in denial of human-driven, fulminating ecological degradation, already visible on the far horizon. The children will have extraordinary difficulties responding ably to that with which they could soon be confronted; that is to say, “they will not even know what hit them,” much less WHY?



  12. Concerning population getting more attention, see a recent thread of comments on the Worldwatch Institute site:

    They asked, “Help us decide what the big stories will be in 2009—and help us pick the theme that best ties them together for a compelling package.” And they’re getting some excellent replies concerning population. Look for comments from “Mike in L.A.” and others. Once I finish reading, I’ll chime in with my own.

  13. Thanks for the reference to the WorldWatch website. At least WWI is willing to ask the correct question. Dr. Stephen Hawking did this very thing recently, but went nowhere with it.

    By now our leaders surely have some idea of the role certain overgrowth activities of the human species are playing in bringing about the fulmination of converging global challenges.

    How much longer can the leaders of the human community fail to so much as acknowledge that the huge scale and anticipated growth rate of the human population is forcing the nest of emerging global challenges for which there is evidence virtually everywhere we choose to look?

    Hopefully, my not-so-great generation of elders will not much longer take our children down a “primrose path” toward a calamity (in the making), one which results from denying what is real, wasting too much time, dissipating too many resources, degrading too much of the environment, and destroying the Earth as a fit place for human habitation.

  14. Here is the first page of comments in response to Worldwatch’s call for ideas:

    I would urge others to leave suggestions as well. If Worldwatch has the honesty and courage to center the report around population overshoot or another of the (few) central aspects/causes of the ecological crisis we face, not shying away from anything just because it’s contentious, it would help raise awareness worldwide.

  15. Once again, John, many thanks to you.

    And yes, what is plainly necessary now is intellectual honesty and courage as well as “centering” on the threat to humanity, life as we know it, the environment and the integrity of Earth that is posed by the gigantic scale and unsustainable growth rate of the human population worldwide.

  16. The leaders in my not-so-great generation wish to live without having to accept limits to growth of seemingly endless economic globalization, increasing per capita consumption and skyrocketing population numbers; their desires are evidently insatiable; they choose to believe anything that is politically convenient and economically expedient; and they act accordingly; but, despite all their shared fantasies and soon to be unsustainable activities, Earth exists in space-time, is bounded and has limited resources upon which the survival of life as we know it depends. Whatsoever is is, is it not?

  17. Which resources are you particularly concerned about here? I fail to see how we cannot keep up with the demand of a growing human population.
    Check this stat: Between 1776 and 1975, while the world’s population increased sixfold, real gross world product rose about 80-fold. People are net resource producers.

    What makes you think we are not able to continue to improve the methods we use to provide food and energy to ourselves with technology?

  18. Ben,

    So are you saying the earth is not finite? Hmmm…

    Oh, and here’s your source:

    …The Cato Institute, one of the most anti-environmental, climate change denying, population growth dismissing, propagandizing so called libertarian “think tanks” on earth. Something from at least a semi-legitimate scientific organization or individual might be more convincing. Try these for starters:

  19. Ben’s comment above, paired with his comment on climate change, shows well the gist of the views of many on the right (in this case the libertarian right) who deny the problem of population growth. They also deny the problem of climate change. The common thread? For many of this ilk it’s the feared loss of potential profits in a “free market.”

    This has been well examined with regard to climate change, but less so regarding population. Dismissal of the latter often stems from the notion that population growth is necessary for economic growth. The stance, then, is that of the “cornucopian” and, as William Catton puts it, the “cargoist” (as in the cargo cults of the South Pacific post WWII) who contend the earth will always provide due to their unwavering faith that unknown or fantasized future technologies will always solve the problems created by population overshoot. It simply denies the fact that the earth is finite, and therefore capable of supporting only so much growth, be it economic (which includes a physical component) or population. (We see today, in the massive levels of ecological degradation caused by humans, the undeniable evidence that that those levels of growth have been far exceeded.)

    The pinnacle of this nonsense was the contention of the late economist Julian Simon, a libertarian icon, that we could support “an ever-growing population for the next 7 billion years.”

    Al Bartlett pointed out nicely that at a 1% growth rate (today’s is about 1.14%) the global population would equal the number of atoms in the known universe in just 17 thousand years.

  20. Hi John,

    I’m well aware of my source. I sourced it after all. Maybe you can tell me why the enviroleft are always so keen to swat away information with guilt by association fallacies? Seems to me akin to something the religious establishment would previously do to scientists. He’s a heathen and is therefore wrong. It seems to me that if the information provided is influenced by outside factors it would be much easier to refute with logic.

    I wouldn’t exactly describe myself as Libertarian Right (which is a contradiction in terms) as I deteste the Right infringing on my life as much as I do the Left. I’m not an investment banker so I doubt I’m driven by profits. I just don’t like the idea of a very dumb idea dictating what happens to my life.

    That link you provided is from 1992. It mentions such grave problems as ozone depletion which as far as I know is a sorted problem. It also mentions that the Earth is finite. An astounding fact no doubt but just how finite it is surely is the question. Population figures are mentioned but with no mention of the science behind the figures. Can you help me out with the human population YOU think we can sustain and why you think that technology can’t sustain us as it has so easily done in the past?

  21. Ben,

    I had started to write a more detailed explanation of why it’s valid to dismiss the libertarian arguments on population without a lot of explanation. But, that aside, I feel it’s a waste of my time to debate anyone, down here in the comments, on libertarian climate or population denial. The libertarian/Simonian arguments are, IMO, easy to refute. I’ve done so previously (one example), and may do so again in an article before long. But I get little bang for the buck out of debating a lone individual in these comments which only a few people will read.

    Here’s a link for anyone who does want to read critiques of the libertarian environmental view.

    I’m sure, though, there are blogs which would welcome such debate. In fact, you might try some of the peak oil sites as there are a lot more people there to debate you and many of those folks and I share some key views. 🙂

    I’ll give you a tip though. If you think a great deal about human history and population, from the old stone age through the present, and our relationship to all other species, you might find some population-related answers come to you quite clearly. Maybe read an author like Catton (linked to above) along the way. You might find that to be the “ultimate resource.” 😉

  22. No worries John,

    Most arguments I win tend to be because the other person is sick of talking to me 🙂

  23. Magne Karlsen;jsessionid=QBL5USWILOQWZQFIQMFCFFOAVCBQYIV0?xml=/opinion/2007/10/25/do2501.xml#form

    As for motherhood — the fertility of the human race — we are getting to the point where you simply can’t discuss it, and we are thereby refusing to say anything sensible about the biggest single challenge facing the Earth; and no, whatever it may now be conventional to say, that single biggest challenge is not global warming. That is a secondary challenge. The primary challenge facing our species is the reproduction of our species itself.

    … over the years, the argument changed, and certain words became taboo, and certain concepts became forbidden, and we have reached the stage where the very discussion of overall human fertility — global motherhood — has become more or less banned.

    – – – – –

    Boris Johnson is MP for Henley

  24. Hey Magne!

    Where have you been hiding? 😀

    That’s an excellent article. I passed it on to Bill Ryerson of the Population Media Center in the hope that he’ll send it out in his daily emailing of a population-related article. You can get on his list, by the way, by simply asking him through the page or link about that on his site.

    I like this passage too:

    “How the hell can we witter on about tackling global warming, and reducing consumption, when we are continuing to add so relentlessly to the number of consumers? The answer is politics, and political cowardice.”

  25. Before we can find our way forward to a good enough future for our children in a sustainable world, we must find a way to organize and maintain SUSTAINABLE COMMUNICATION about the global challenges posed to humanity by the unbridled growth of the human species.

  26. (November 2000):

    “According to the U.S. Census Bureau, the United States should get ready for a dramatic doubling of its population by 2100.

    “From 275 million Americans today, we can expect to grow to 571 million in the next hundred years. That’s actually a fairly conservative projection. The Census Bureau’s latest estimates actually go as high as predicting that there will be one billion Americans in 2100. This rapid pace contrasts starkly with the more leisurely population growth of the last 300 years. America had only one million people in 1700, and only a little bit more than five million in 1800. Even in 1900, when America’s doors were wide open to immigration and birth rates were accelerating, there were just 76 million Americans. (That number had doubled by 1950, when urban sprawl began in earnest.)”

    “In 1996, the President’s Council on Sustainable Development listed 10 goals, the eighth of which was moving toward stabilizing U.S. population. The report noted that U.S. population was growing at a rate double that of Europe, putting in peril both economic objectives and the quality of the environment.”

  27. Magne, like John I found a gold mine in those links you provided.

    Not long ago I wrote about immigration and US population growth. The first sentence: “Only one country in the world has an advanced economy and a steadily increasing population: The United States of America.” And that’s a serious problem.

  28. Magne Karlsen

    (October 1999):

    “The great problem is population. Despite UN figures suggesting that world population will peak at around 7.3 billion and then fall sharply, and despite ample evidence that the Earth can support a population much larger than this, that people are better fed, housed and educated today than ever before, and that population growth does not cause poverty or environmental degradation, the UN is absolutely committed to the line that “we have to stabilise the population of this planet.””

    “The UN’s use of language as a political tool would have impressed George Orwell, its Western-feminist wording being unintelligible to many nations. In order to get key passages approved before the delegates realise what they are really saying, they introduce terms such as “gender”, “sexual orientation” and “reproductive health” without defining them, but with implications far removed from their usual meanings. Translations disguise the ideology or are not supplied at all, so many delegates have no idea what they are voting on.”

    – —

    But the idea of birth control or mandatory family planning remains a taboo topic of sorts. It’s what is being done in China, and it doesn’t apply to us. And Chinese politicians do not know much about fundamental freedom and a basic human rights, do they?

  29. Magne Karlsen

    Funny UN people: “population growth does not cause poverty or environmental degradation,” — a statement made eight years ago. I wonder: what are they saying now?

  30. Magne, The UN is talking a little more sensibly about population right now. Here’s their latest report on the state of the environment:

    And here’s a line I pulled from the executive sumary:

    “The drivers of environmental change include population growth, economic activity and scientific and technological discoveries.”

    Here’s another:

    “A sixth major extinction is under way, this time caused not by natural disasters but by human population growth and
    consumption patterns.”

    I think we’re seeing the early stages of a resurgence of recognition of the population factor. I hope so anyway.

  31. Pingback: myriad views on overpopulation « Trinifar



    Drought could put us in dark: Electric utilities are the biggest
    users of Georgia’s freshwater, but their role has been largely

    By Ken Foskett, Margaret Newkirk, Stacy Shelton
    The Atlanta Journal-Constitution
    November 18, 2007

    Historic drought worsens and the tri-state water battle
    escalates, Georgia policymakers are all but ignoring the region’s
    biggest water guzzler.

    Electric utilities are the single largest users of the region’s
    freshwater. A family of four can use three times more water to power
    their home than they use to drink, bathe and water their lawn.

    In Georgia, electric utilities use 68 percent of all surface water,
    the single largest user in the state, according to 2000 data from the
    U.S. Geological Survey, the latest year available.

    “We’ve been working really hard over the years to tell people when
    they flip that light switch, the water is running,” said Sara
    Barczak, with the Southern Alliance for Clean Energy, an advocacy

    Yet the link between power generation and water use has been
    virtually ignored in the debate over how to fairly allocate the
    region’s water resources and plan for growth.

    Neither of the region’s principal blueprints for water use —- the
    state water plan and the North Georgia metro water plan —- include
    strategies for managing water demand by the power industry.

    Where does water come up? In the state’s official energy plan. It
    quotes research that makes the connection: The public “may indirectly
    consume as much water turning on the lights and running appliances as
    they directly use taking showers and watering lawns.”

    Carol Couch, director of the state Environmental Protection Division,
    declined an interview request to explain why the state water strategy
    doesn’t include conservation by the biggest water user. Kevin
    Chambers, an EPD spokesman, said utility water use would be discussed
    in the next round of planning, examining the specific water
    requirements in the state’s 14 water basins………………………………………

  33. Feeney: Having overshot the earth’s capacity to sustain our current numbers, living as we do, we must act now to avert catastrophe. We’ve depleted resources such as oil and groundwater and have damaged the global ecosystem, triggering a wave of extinctions. We’re dismantling the web of life. A growing number of analysts warn that if we fail to reduce both per capita consumption and to halt the growth of our population no new technology will prevent an unimaginable loss of life. The poorest countries will be the most vulnerable. We in the developed world, with the resources to act on these needs, have a moral imperative to do so.

    Mr. Green: All very commendable but not very realistic. A Darwinian solution is likely to unfold: those that have will try to keep what they have while dealing with their own population problem when they are forced to. That means that Africa and South America will get few resources from the have nations. Life will get worse there and populations will decline. China and the US (maybe India) will increasingly struggle for diminishing resources, perhaps to the extent of war. Europe may possibly survive if it is able to become a “local” economy with reduced resource demands and population.

    When deer herds become too large for their territory, disease and starvation shrink the herd.

    It’s not very pretty and nor humane but it’s a scenario nonetheless.

  34. Mr Green, that’s precisely the scenario that can and should motivate us to change our policies consciously and soon, rather than sit back and let “bussiness as usual” play out.

  35. Pingback: If by overbear you mean… « overbear