world population
When I was researching the article One Billion Americans?, I got thinking about the implications of the wildly conservative Census Bureau projections of US population, and the embarrassing drastic upward revisions that have been made to them, for global population projections. What made the US projections so wrong (US population peaking at 295 million was predicted as recently as fifteen years ago) was the compound error of underestimating the extent of immigration and overestimating the rate at which immigrants adjust their family size to the average of their new country, or the global average. It’s an understandable error — there’s lots of evidence that population growth rates in the developing world are falling quickly. But that’s not because third world countries are evolving to two-child-or-less families as infant mortality drops. Rather, it’s because those countries are simply unable to sustain more children, so parents are reluctantly, temporarily reducing family size as a result. Give them the option to emigrate to a developed country, and cultural preference, religious dictates, and improved health care will jump their family size (and life expectancy) back up again. And as inevitable ecological and humanitarian catastrophes arise in the 21st century in dozens of third world countries, compounded by the scourges of new diseases, horrendous shortages of clean water, and desertification and crop flooding due to global warming, the pressure to increase immigration quotas by orders of magnitude will be fierce.

Back in 1990 when the pundits were predicting US population would peak at 295 million (it passed that level last year and is now expected to peak at between 550 million and 1.2 billion, if it peaks at all), they were saying global population would peak at around 9-11 billion in 2100. But for that to happen with a US population of, say, 900 million instead of 300 million, would mean average third world family size would be much smaller than average US family size. The UN projections, for example, assume annual average growth rate for Africa, Asia and Latin America of 0.5% in the latter half of this century, compared to a current growth rate in those areas (even including China with its already-low birth rate) of 2.1%, and compared to a current US growth rate of 0.9%, which is trending back up to a projected 1.3% rate for most of the current century, thanks to immigration.

So the 9-11 billion global peak population just doesn’t add up. While it doesn’t make sense to get Malthusian and project population will grow indefinitely at current rates (1.3%, i.e. a doubling every 50 years to 24 billion by 2100), it’s equally illogical and irresponsible to suggest that the whole world will start immediately radically reducing its fertility rate to achieve in just two generations the low fertility rate that Europe took one hundred generations to reach. If you assume that the levels of immigration now projected by the US Census Bureau will prevail throughout the developed world, that first- and second-generation citizens of developed countries will continue to have considerably larger-than-replacement level families in their new adopted countries, that the prevailing pro-fertility population dogmas of organized world religions will not suddenly be changed, that population pressure in the third world will be eased somewhat by immigration and that modest drops in family size in those countries will be largely offset by longer life expectancy, as has been observably the case in almost every third world country except China, then instead of the 9-11 billion peak the UN is currently talking about, you end up with population soaring past 14 billion in 2100, with no end in sight (left chart above).

The curved red line shows the carrying capacity of Earth, assuming a modest annual increase in productivity from the current 30 billion acres (productive-capacity adjusted), assuming average footprint per capita continues to increase by a modest 1% per year, and assuming no land on the planet is reserved for wilderness or natural space for the rest of Earth’s creatures. It shows in 2000 that the world could sustain 5 billion humans at the then-prevailing level of consumption. That’s a billion humans less than actually inhabited the planet then, possible only by depriving much of the world of a subsistence level of resources, and by taking more from the Earth (in non-renewable resources) than we replaced, essentially stealing the excess from future generations. At the expected global level of per-capita consumption in 2100 (still well below today’s North American consumption levels), carrying capacity drops to 2 billion humans. That number is substantiated by a recent Cornell study that says the choice in 2100 is between 2 billion people living a comfortable but not lavish life (achieved by a drastic population reduction) or 12 billion “struggling in misery”. And if you want to allow 50% of the planet’s surface for other life forms, you need to achieve double that reduction (green line), to one billion people, the level both Jim Merkel and Bill McKibben think we should strive for. That’s only achievable, short of coercion, by an average one child family worldwide for the next century.

The right chart shows that the increasing average footprint, driven both by North American excess and the surging resource use of China’s billion plus people, will drive the aggregate human footprint up even more sharply than aggregate population, from 37 billion acres today (20% more than Earth’s carrying capacity) to 210 billion acres in 2100 (six times Earth’s carrying capacity). Now remember, these assumptions are much closer to the wildly optimistic assumptions of population levelling that the UN and other global agencies optimistically hope for, than to the Malthusian no-change projections that would see nearly double these numbers. Nevertheless, train wreck ahead.

We simply have no choice. We must immediately and aggressively reduce our family sizes worldwide, and we must immediately and aggressively reduce per-capita resource consumption, waste and footprint. That means we must confront religions that don’t actively encourage birth control and small families, and show those religions to be socially irresponsible. That means, too, we need to introduce ecological taxation measures to make excessive resource consumption and waste prohibitively expensive, and reward those who tread lightly on the Earth.

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  1. Philip says:

    When you say immediately and aggresively just how aggressive do you mean to be? Do we nuke India first or Brazil? ‘Cause democracy ain’t going to go for immediate and aggressive. Keep your hands off my gonads thank you very much! I’m pretty sure the United States would resist vigorously any attempt to enforce your vision of Utopia on it. If you expect people en masse to submit to voluntary sterilization you need a reality check.Coercion is the only way to immediate (and it is pretty damned aggressive too) results. Who is in charge of your eugenics program?

  2. Clonal Antibody says:

    You are wrong about it taking 100 generations in the Western countries to reach the low growth levels. In fact it took 4 generations. Until the 1920’s, and the Family Planning movement, the average family size in Europe and India was about the same, with only slightly higher fertility rates in India and China — mainly to compensate for the slightly higher child mortality rates.In fact in Southern Indian states, the fertility rate is already approaching 2.5, while in the state of Kerala, it is slightly below 2.And this has been achieved without coercion. In fact, the only attempt at coercion around fertility issues backfired very badly, setting back the clock in India by 10 years.

  3. mrG says:

    Cheer up: Iran is hardly planning to beef up (or enforce) it’s building codes, SARS is back, AIDS is bigger than ever, most of the really dense areas are rife with genocides and devoid of sanitation, and GWB hasn’t shown any signs of abandoning his personal Jihad (just make sure you re-elect him!) — lots of dedicated and dilligent people are working overtime doing their utmost best to ensure that only the most model communities could possibly survive!And then there’s the Malthusian blindspot: Innovation. Malthus never expected refrigeration or vaccines, and in just the past year we’ve seen a car sail across Australia on sunlight, we’ve seen primative (particle) time-travel and a lot of genome mapping … maybe we can stash excess people in the past (I think the book was called Time Hoppers, but I don’t remember the author. Heinlein?) … only be sure it’s the right people :)

  4. Clonal Antibody says:

    Here is the Kerala Link “how” of population stabilization thus becomes the essential question.In order to answer this “how” question, we look at the real-life, today experiences of the Malayalam speaking population of India living within the state of Kerala. In Kerala there are low and stable birth rates. Total fertility rates have been holding steady at 1.7 for ten years. In and out migration being equal, Kerala has achieved population stabilization.In addition, standardized well-being measures (not including incomes) in Kerala are approximately equal to the all Europe averages. That is, life expectancy, infant mortality rates, and educational levels. It is these high well-being measures which explain the voluntary choices of the moms and dads of Kerala for small families.The “how” answer is not economic. Kerala has the lowest economic growth rate of all states in India, near to zero. Economists, therefore, have excused themselves from explaining any of these facts: *the life expectancy of men in Kerala is ten years longer than in all India.*the life expectancy of women in Kerala is fifteen years longer than in all India.*infant mortality is four times lower in Kerala than in India.*the total fertility rate of Kerala is half that of India.

  5. Clonal Antibody says:

    Another Kerala Link Nobel laureate and economist Amartya Sen notes that the “eastern strategy” of focusing on human development and, more broadly, on acknowledging a fundamental complementarity between the State and the market provided strong support for China’s post-1979 economic development.Big deal, champions of Kerala will snort: We are on a par with, if not better than, China on indicators like life expectancy, literacy, gender bias and female education.True, Kerala compares admirably with China. Female education has expanded much faster in Kerala than in China.Fertility rates have also declined more rapidly.Between 1779 and 1991, while the Chinese fertility rate dropped from 2.8 to 2.0, Kerala’s fell from 3.0 to 1.8.Currently, Kerala’s fertility rate is below 1.7, while China’s is around 1.9.But remember – and this is where our Chinese lesson begins – in 1979, China introduced its controversial “one-child family policy” and other coercive measures, including economic penalties and punitive steps, to control its fertility rate.Kerala used no coercion, yet achieved a significantly better result than China.That was because Kerala’s achievements were based on freedom and empowerment of women through greater paid employment and gainful activities outside the household, better and more widespread education, and access to participation in public and civic bodies.That was also why Kerala’s infant mortality rates continued to fall in the absence of overt State action.

  6. Dave Pollard says:

    Philip: When I said “we need to” I meant all of us on Earth, taking collective responsibility. I know it’s not going to happen by coercive means. I’m not proposing anything monstrous, just calling for a global movement of action, awareness, and personal decision. Maybe naive, but not impossible, and the only hope we have.Clonal: This is really interesting data, thanks. Merkel visited and studied Kerala and talks a lot about it in his book Radical Simplicity. No one seems to be able to explain it, and it remains an anomoly in the developing world. Contrast it with Chile, which is the most affluent Latin American country, and has an excellent education system, but continues to double in population every 50 years — double the rate in my charts. What are the people of Kerala doing right that the people of Chile (and most of the rest of the developing world, regardless of wealth) aren’t? Is it just the matriarchal bent of Kerala? If so it doesn’t bode well for the rest of the mostly patriarchal world.Gary: I knew you were going to bring up innovation. The data in my charts are anticipating on a lot of it, to counter the loss of arable land due to urban encroachment, desertification and overuse of chemical fertilizers. Masses of innovation will be needed to increase agricultural and mineral production in spite of excessive depletion of available resources, and to address the damage that all this human production and consumption will produce. Just solving global warming, for example, will take more innovation, and more will, than has been in evidence to date.

  7. Clonal Antibody says:

    Dave,I think you may have overlooked the role of women’s emancipation as a cause of declining birth rates in US and the developed world. My hypothesis has long (over twenty years) been, that contrary to widely held belief, economic betterment had relatively little to do with the declining birth rates in western societies. My take on it is that only three things led to the voluntary decline in the fertility rate1) Women’s emancipation and education2) Abolishing Child labor3) Compulsary and free early education for allIf you noted in my posts, the rest of Southern India is not far behind Kerala. Norhthern India would also have been somewhere there, had it not been for the coercive episodes of force sterilizations that took place in North India in the early to mid 70’s. That set back the clock there by about ten years. That is the difference I believe. Even in North India, women’s movements are fast gathering speed, and integral to those movements is a drive towards giving women more reproductive rights. You may say that India is special — because there is a lot of Goddess worship, and hints of matriarchy. Latin America may lack that, but I believe that the women of Latin America will come up with their own solutions.

  8. Stonethatbleeds says:

    I have a templatethat can do all you need to save the world and more. Balance populations, feed the world, even cure many things and even create things Humans need for the future, today.This template makes the perfect solution world wide for all the problems of Humanity!Just ask at for a picture of the template that is free from me to anyone that wants it. Saving the world with the template is easy!Just build it and see!

  9. Philip says:

    Reality check Dave “we” *all of us on earth* don’t read your blog. Many of us are more obsessed with eating than population control. We do not tend to think globally. It is a shame I know it is just the way it is. You talk about moving immediately and agressively as a species when we have NEVER done such a thing in our history. You seem to believe every person on earth needs 15 acres of arable land (why not 50?) You pick a nice millenial number of 1 Billion as the perfect number of human beings for the planet. And if we don’t act immediately and agressively well what? The world as we know it will come to an end? 9 out of 10 human beings will die? (Isn’t that what you want?!)We will do as we have always done we will adapt or die. If enough of us die, problem solved? I’m going to go hand out blankets it’s cold on the steets of Portland today. For me it is a matter of priority. Kerala sounds cool we should all go live there, I know I might be able to afford to retire there!

  10. Dave Pollard says:

    Philip (sigh) — I commend you for your actions helping the poor and homeless in your city. Happy New Year.

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