Bartlett replies: The appealing assertion that Thomas Robert Malthus has been proven wrong denies a fundamental mathematical truth. Malthus recognized that the growth potential of population is greater than that of food production; that realization led him to predict widespread starvation. Mark Meier writes that Malthus has been proven wrong because “food has never grown scarce … [and] today, more people are fed more affordably and with larger varieties of food than ever before.” However, global agricultural scientists report that, despite all manner of scientific and technological advances in agriculture,
increases in food production, per hectare of land, have not kept pace with increases in population, and the planet has virtually no more arable land or fresh water to spare. As a result, per-capita cropland has fallen by more than half since 1960, and per capita production of grains, the basic food, has been falling worldwide for 20 years…. The World Health Organization estimates that more than 3 billion people are malnourished…. This is the largest number … of malnourished people ever reported. 1
Malthus’s prediction is now becoming reality. In addition, the observations of those agricultural scientists bear out Kenneth Boulding’s elaboration of Malthus’s idea: “The final result of [technical] improvements … is to increase the equilibrium population, which is to increase the sum total of human misery.” 2
A similar thing seems to be happening in petroleum production. My graph (page 54 of the July article) showed that world per capita petroleum production has declined significantly since it peaked in the 1970s at about 2.2 liters per person-day. That decline is clear evidence that the numerator, production, is growing less rapidly than the denominator, population; and as Douglas Davidson reports, the growth rate of the denominator is decreasing significantly.
Two possible explanations come to mind for such a drop in the growth rate of petroleum production: either declining demand “while supplies were plentiful,” as Meier suggests, or declining growth in production that is expected as production approaches the top of the Hubbert peak, the point at which world oil production reaches its maximum and starts its inevitable long-term downward trend. Many scientific analyses suggest that the peak will occur within the next decade or two, 3 which is consistent with my interpretation that the observed decline in the growth of world per capita petroleum production is mainly due to the approaching maximum of world petroleum production.
These observations are reflected in news stories such as one from a Boulder, Colorado, newspaper in mid-September: “Oil prices have soared in recent months because of the extremely thin margin of spare output capacity worldwide and fears of supply disruptions around the globe.” 4 I can’t see that this “unwittingly contradicts” my thesis, as Meier says. These food and petroleum data combine to exacerbate the Malthusian picture. Note that modern agriculture has been referred to as the use of land to convert petroleum into food.
The tragedy is not a periodic reemergence of the Malthusian mathematical truth. The tragedy is our continued eagerness to ignore that truth. We do so at great peril.
It is irresponsible for scientists to suggest that the large tabulated total energy content of biomass, oil shale, oil sands, heavy oil, and nuclear fission can cover world energy demand for the long-term future. Meier suggests that these sources “represent at least a thousand years of world energy demand.” Such suggestions should not be made until the public is aware of thoughtful estimates of the net energy gained in extracting and consuming each of these resources, the necessary costs, in time and dollars, to develop them on a scale sufficient to affect global energy needs, the environmental and human costs of their development and use, and the secondary human and systemic problems that will predictably result when the enormous capital resources needed for development are diverted from traditional investment channels.
Douglas Davidson is correct that the “world population growth rate is already falling.” However, current projections suggest that world population will grow from the present 6.3 billion to between 9 billion and 11 billion before it stabilizes late in this century. Does anyone think that a world of even 9 billion people will be a better, more just, or more peaceful world? And Frank Haig is ahead of his time, worrying about extinction when the world population is growing by about 75 million people per year.
As David Goldstein observes, the technological potential for improved efficiency of energy use is enormous. But technology brings new ways to consume energy as well as to conserve it. If we are going to stretch the lifetimes of fossil fuels “consistent with geophysical constraints,” we must recognize the constraints and then combine the effects of technology and population growth so that there is a decline in total annual energy use; 5 that achievement will almost certainly require stabilizing population at the earliest possible date.
Much has been published about the growing problems associated with global warming. The following truth is self-evident: If any fraction of the observed global warming is due to human activities, then this constitutes positive proof that the human population, living as it does, has exceeded Earth’s carrying capacity—a situation that is not sustainable.
In his 1966 acceptance speech for the Planned Parenthood Federation of America’s Margaret Sanger Award, the great humanitarian Martin Luther King Jr spoke about the population problem:
Unlike plagues of the dark ages or contemporary diseases we do not yet understand, the modern plague of overpopulation is soluble by means we have discovered and with resources we possess.
What is lacking is not sufficient knowledge of the solution, but universal consciousness of the gravity of the problem and education of the billions who are its victims.
When scientists seek solutions to problems caused by population growth, it is professionally unethical not to list stopping population growth as a central part of the solutions. If scientists don’t speak out, who will?
