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Population, Consumption, Carbon Emissions, and Human Well-Being in the Age of Industrialization (Part II — A Reality Check of the Neo-Malthusian Worldview)

By Indur Goklany -- April 23, 2010

Editor’s note: This is the second of a four part series. Part I provided a long-term view of commodity prices, their affordability and the impact on human well-being. Here, Indur M. Goklany looks in more detail at global trends in human well-being in the Age of Industrialization, from 1750 – 2007. (Part III and Part IV are here.)

In the worldview of many environmentalists and Neo-Malthusians, as population and economic development increase so does the consumption of energy, land, water and other natural resources. Originally, Malthusians feared that we would run out of these resources, and natural resource–based products, particularly food, would be in short supply, resulting in famine and a general decrease in human well-being. But as shown in the previous post, instead of becoming scarcer, resources (such as metals and food) actually have become more affordable, and the hunger and famine that had been foretold went AWOL. [I will out of charity, not beat the dead horse of Paul Ehrlich’s failed predictions.] Elsewhere, I have also shown that, at least before the enactment of government policies to boost biofuels, land and water use had, more or less, stabilized in the richer world and, possibly, worldwide (see here and here).

Today, Neo-Malthusians focus more on pollution, environment, and climate change, consumed by the notion that the by-products of all the production and consumption that underlies humanity’s economic activity would overwhelm the earth’s assimilative and regenerative capacities. This view is captured in the identity, I = PAT, where I is a measure of impact (usually, environmental impact); P is the population; A stands for affluence, and is measured by per capita production or per capita consumption and often proxied by the gross domestic product (GDP) per capita; and T, denoting technology, is a measure of the impact per unit of production or consumption. Notably, the product of P and A is the GDP, that is, consumption. Therefore, under the IPAT formulation: (a) T is the ratio of impact to GDP, which I will call “impact intensity,” and (b) the impact should grow in proportion to GDP.

As noted here:

The IPAT identity has been remarkably influential. It has intuitive appeal because of its apparent simplicity and seeming ability to explain how population, consumption or affluence, and technology can affect human and environmental well-being. It serves, for example, as the “master equation” for the field of industrial ecology (e.g., Graedel and Allenby 1995). One of its versions underpins the Intergovernmental Panel on Climate Change’s emission scenarios … (IPCC 2000, pp. 83–84)…

Despite recognizing that “benign” technology could reduce some impacts, many Neo-Malthusians argue, to quote Jared Diamond (2005, p.504), it is a mistake to believe that “[t]echnology will solve our problems.” In fact, goes this argument, “All of our current problems are unintended negative consequences of our existing technology. The rapid advances in technology during the 20th century have been creating difficult new problems faster than they have been solving old problems…” Diamond (2005, pp. 505). Ehrlich and co-workers argue that for most important activities, new technology would bring diminishing returns because as the best resources are used up (e.g. minerals, fossil fuels and farm land), society would increasingly have to turn to marginal or less desirable resources to satisfy demand which would increase energy use and pollution (Ehrlich and Holdren 1971; Ehrlich et al. 1999).

According to the IPAT identity, if all else remains the same, an increase in population, affluence or technology would each act as multipliers for environmental impact (e.g., Ehrlich and Holdren 1971; Ehrlich 2008). And as that impact increases, human well-being would necessarily deteriorate. The IPAT identity has been used to support the contention that the human enterprise as currently constituted is unsustainable in the long run, unless the population (P) shrinks, we diminish, if not reverse, “overconsumption” or economic development (A) (particularly in the United States), and apply the precautionary principle to new technologies, which in their view essentially embodies a presumption against further technological change unless the technology involved is proven safe and clean in all respects (Ehrlich and Holdren 1971; Ehrlich and Ehrlich 1991; Myers 1997; Raffensperger and Tickner 1999).

But do empirical data support the notion that increasing population and consumption coupled with technological change reduces human well-being?

Figure 1 shows global trends from 1760 onward for population, affluence (GDP per capita), CO2 emissions, and life expectancy (a surrogate for human well-being).

Part II Figure 1

Figure 1: World population (P), GDP per capita (A), life expectancy (LE), and CO2 emissions from fossil fuels in the Age of Industrialization, 1760-2007. Data for P, A and LE are sporadic until 1960. This figure assumes that trends between adjacent data points are linear. Sources: Maddisson (2003, 2010); World Bank (2009); CDIAC (2009).

It shows that contrary to the Neo-Malthusian worldview, despite an octupling of global population, and increases in affluence by an order of magnitude and CO2 emissions by three orders of magnitude, the state of humanity — as measured by average life expectancy at birth, the single most important indicator for human well-being — has advanced. In fact, life expectancy more than doubled from 26 years to 69 years. Table 1 summarizes the changes from 1750 to 2007.

Part II Table 1

Table 1: Global Population, Affluence, CO2 emissions, and Life Expectancy, 1750–2007. Sources: Maddison (2010), CDIAC (2009), World Bank (2010).

Not only are we living longer, we are also healthier, as is evidenced by the fact that for virtually every country, the Health Adjusted Life Expectancy — life expectancy adjusted downward to account for life years spent in poor health — currently exceeds the unadjusted life expectancy from a few decades ago (see, The Improving State of the World: Why We’re Living Longer, Healthier, More Comfortable Lives on a Cleaner Planet, page 40). And as anyone who has travelled elsewhere recognizes, water and food are safer in richer countries.

By contrast to safe food and water, the situation with respect to other environmental indicators is more complex. Empirical evidence suggests that as countries advance economically and technologically, some environment indicators (e.g., air pollution and some water pollutants) first gets worse, then, as they achieve a certain level of development, the environmental deterioration peaks and the indicator begins to improve again. This “environmental transition” can be explained by the environmental transition hypothesis that initially societies opt for economic and technological development over environmental quality because such development allows them to escape from poverty and improve their quality of life by making both needs and wants (e.g. food, clean water, education, health, homes, comfort, leisure and material goods) more affordable. But once basic needs are met, society begins to perceive that environmental deterioration compromises its quality of life, and starts to address its environmental problems. Being wealthier and having access to greater human capital, it is now better able to afford and employ cleaner technologies. And also with the passage of time, society now has access to improved technologies that are cleaner and/or more effective. Consequently, environmental deterioration is, first, halted and, then, reversed. Thus, technological change and economic growth may initially be the causes of environmental impacts, but eventually they work together to effect an “environmental transition” — after which they become a necessary part of the solution to environmental problems. Thus we see that rich countries have better air quality, for instance, as do many poor countries, while countries in-between have worse air quality.

Figure 2 presents a stylized representation of the Environmental Transition Hypothesis.

Part II Figure 2

Figure 2: A stylized depiction of the Environmental Transition Hypothesis, a generalization of the Environmental Kuznets Curve. It shows the evolution of environmental quality – the negative of environmental impact (EI) – as a society evolves from a low to a high level of economic development. The figure assumes that affluence and technology advance with time, which is broadly consistent with historical experience since the start of the Industrial Revolution. NOTE: p(P) = “period of perception,” the period during which the notion that environmental degradation can compromise human well-being gains acceptance; p(T) = “period of transition,” the period over which that perception leads to actions which eventually reduce environmental degradation; “Race to the Bottom Region” (where society strives to increase economic development despite increasing EI); NIMBY Region = “not in my backyard region” (EI enters this region if benefits far exceed costs to beneficiaries); C/B Region = cost/benefit region (where benefits and costs have to be more carefully balanced). Source: Goklany (2007)

In my next post, I will focus on long-term trends for population, consumption, and affluence for the U.S., and verify whether its human and environmental well-being have been compromised by the increased use of fossil fuels, synthetic chemicals, metals and other materials.


  1. Matt  

    You’ve premised your argument on the assumption that GDP correlates to wellbeing. It does up to a certain point, as you provide basic level services for people. However, as the consumption/GDP continues past this point, the happiness/welbeing stays flat while consumption rises.
    It seems that by labeling realists as “neo malthusians” you are able to make cherry pick silly arguments regarding how realists are somehow anti-technology. Nothing could be farther from reality. Technology has not created more problems. Our culture of consumption has created the problems. Technology has simply been unable to keep pace with our ever expanding appetite for consumption. You cannot consume your way to happiness. It’s about sufficiency, not excess. I’d suggest focusing on success metrics for your next post, not a continuation of this self fulfilling, head in sand prophecy.


  2. Down PAT | The Rational Optimist…  

    […] always perceptive Indur Goklany has turned his attention to IPAT, the formula by which some environmentalists insist that human impact (I) gets worse if population […]


  3. Steve Burrows  

    Reading this series of posts with much interest, I’ve been finding it a very useful summary of this topic.


  4. Jon Boone  

    Neo-Malthusians such as the Ehrlichs, Jared Diamond, Lovins, etc, have more in common with eschatology than they do the disciplines of economics and science. That they are occasionally correct has more to do with the fact that a stopped clock is right twice a day than it does with the successful predictions wrought by scientific rigor.

    I too will look forward to Parts III and IV.


  5. Jon Boone  

    Although I can’t agree with Matt that Ehrlich, et al, are “realists” in any functional sense, he does have a point about the lack of a good operational definition of “happiness,” a concept kept purposely vague by Jefferson, who evidently believed that its pursuit was sufficient for good society. GDP is one of many possible measurements of happiness–or its absence–but no metric is the same as the thing itself.

    Matt and others might read Gary Wills’ Inventing America, who provides a stimulating discussion about happiness as it relates to life, liberty, and property, covering Locke, William Wollaston, Francis Hutcheson, Adam Ferguson, George Mason, and Ben Franklin, as those stalwarts struggled to provide at least contextual understanding of the concept in the 18th Century.

    For me, consumption, at many different levels, contributes to happiness. The question, as is the case in so much of life, is what constitutes satiety. I love the new Ipad, on top of my computer, pickup truck (to get around mountain terrain), HDTV, an old Victorian home. I also thrive on mediative walks through old-growth forest, where no human technology encroaches for miles around, and by reading 200-year old books by a quiet fire. I don’t feel at all that I’m putting either my neighbors, the people of Africa, or the planet at risk by over-consumption. Quite the contrary. I’d love for all to have what I have, and more, if they wish.

    So, come on, Matt, tone down your jeremiad, leavened as it is with self-righteous notions about consumption, and help fashion a practical public policy that protects–even enhances–the best of our modernity. Which I think that Indur Goklany is working to do here.


  6. Indur M. Goklany  

    Thanks for your comments. Matt. Following are specific responses — your comment, followed by my response.
    MATT: You’ve premised your argument on the assumption that GDP correlates to well-being. It does up to a certain point, as you provide basic level services for people. However, as the consumption/GDP continues past this point, the happiness/welbeing stays flat while consumption rises.

    RESPONSE: First, I agree, wealth or GDP per capita does not buy happiness. But I do not (and would not) equate “human well-being” to “happiness”. My work is based on objective measures of well-being. See, e.g., http://www.ejsd.org/docs/HAVE_INCREASES_IN_POPULATION_AFFLUENCE_AND_TECHNOLOGY_WORSENED_HUMAN_AND_ENVIRONMENTAL_WELL-BEING.pdf or page 376 of the book The Improving State of the World: Why We’re Living Longer, Healthier, More Comfortable Lives on a Cleaner Planet (link is provided on the left of this page). I am sorry that this wasn’t emphasized in the blog. So please accept my apologies.

    “Happiness,” on the other hand, is literally a state of mind and, therefore, quite subjective. You will not see any reference in my work to “happiness”.

    Second, using life expectancy (LE) as a measure of human well-being, the relationship is not between LE and GDP, but LE and GDP per capita. Third, the relationship between the latter two is logarithmic. So while the slope declines, it does not quite flatten out. So, yes, the poorest folks get the greatest extension of LE for every dollar of income, but, all else being equal, richer will live longer, but every additional dollar will get that much less.
    MATT: Technology has not created more problems. Our culture of consumption has created the problems. Technology has simply been unable to keep pace with our ever expanding appetite for consumption. You cannot consume your way to happiness.

    RESPONSE: I am glad we agree that technology has not created more problems, but it certainly has more than kept pace in terms of ensuring that the objective measures of well-being continue to improve, as the data presented here for LE (and health) show. But we are talking about two different things. You are talking about “happiness” and I am talking about objectively measured well-being.

    Finally, you have no quarrel with me when you claim that “you cannot consume your way to happiness.” I don’t equate consumption with happiness. I am skeptical that many people do, or ever did, as evidenced by the old saying, “money doesn’t buy happiness.” If some people consume more on the basis that they are going to be happier, it’s a tip-off that their lack of happiness is due to a more fundamental factor than lack of consumption. However, it’s unclear what are “the problems” (that you refer to) that consumption has created.


  7. Indur M. Goklany  

    Rational Optimist, thanks for visiting.

    For readers of this blog, Rational Optimist has some interesting observations and poses very interesting question regarding how much land is needed to provide energy for a light bulb today versus how much land was needed to get equivalent lighting via tallow.

    RO: I will post some info on a related matter on your website later today, but I do not have the exact answer to your precise question.


  8. Robert R. Reynolds  

    I was born in 1917 and feel I was able to “ride the curve” of rising expectations to its apex in the 1990’s. The Green fantasy of AGW is an attempt to halt the rise of expectations to a sustainable level that will first affect the populations of the poorer countries of the world. I believe I was most furtunate to have lived in the “best of times” man has achieved during his short reign on Earth. About 10 years ago an article appeared in Geotimes (now Earth) that estimated at 6 billion, the earth was overpopulated by a factor of 4 times if everyone was to live on the scale of northern Europe and the United States. I regret that this has come to pass within my long lifetime.


  9. Goklany takes on greens - danielbenami.com  

    […] always interesting Indur Goklany takes on neo-Malthusians and environmentalists in this post on the masterresource website. He gives useful statistical examples of how human well-being has […]


  10. U.S. Well-Being in the Age of Fossil Fuels | Think Tank West  

    […] Elsewhere, I have shown data that, notwithstanding the Neo-Malthusian worldview, human well-being has advanced globally since the start of industrialization more than two centuries ago, despite massive increases in population, consumption, affluence, and carbon dioxide emissions. Here I will focus on long-term trends in U.S. well-being, as measured by the average life expectancy at birth, in the age of fossil fuels. […]


  11. Cooler Heads Digest 23 April 2010 | GlobalWarming.org  

    […] A Reality Check on the Neo-Malthusian World Indur Goklany, MasterResource.org, 23 April 2010 […]


  12. Did the Senate “Definitively” Reject Efforts to Rein in EPA? A Commentary on Lautenberg’s Rant  

    […] depend on prosperity and per capita income. Wealthier is healthier, richer is safer. Per capita income, CO2 emissions, and life expectancy are closely correlated. History shows that the cost of cleaner air is very low compared to its […]


  13. Effigy  

    What makes you say life-expectancy is a better indicator, or should I say, a more “objective” indicator of well-being that happiness? To suggest that surviving longer is the best indicator of well-being is a TRAGIC mistake in this type of discussion. In order to fuel the un-ending growth engine required to keep your ship of increasing population, life-expectancy, and consumption afloat you need increasing production, you need growth. Growht needs reproduction and here is where the mistake is made. Life-expectancy is A) an individualistic measure and therefore does not neccesarily relate to the being of the species orm population as a whole and B) does not directly relate to the continuance of suh improvements to the population.

    As an example: A captive animal kept in a sealed box its entire life may life 2X as long, but without the ability to reproduce there is no hope for survival of the species if kept in this fashion, nor for continued evolution.

    oh yeah, and youre also wrong…


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