Lately my mind has been drawn toward Malthusian economics. Perhaps dismal thoughts are needed to counterbalance excessive cheer about the future, the which arose from my recent purchase of a comfortable townhouse at a favorable 30-year interest rate.
Two centuries ago, the Reverend Thomas Malthus, to debunk the boundless optimism of his contemporaries Godwin and Condorcet concerning the perfectibility of man and society, applied his cool and rigorous intellect to examining the checks on human population growth. From Chapter I of An Essay on the Principle of Population (First edition, 1798):
It has been said that the great question is now at issue, whether man shall henceforth start forwards with accelerated velocity towards illimitable, and hitherto unconceived improvement; or be condemned to a perpetual oscillation between happiness and misery, and after every effort remain still at an immeasurable distance from the wished-for goal.
Population, when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio. A slight acquaintance with numbers will shew the immensity of the first power in comparison of the second.
By that law of our nature which makes food necessary to the life of man, the effects of these two unequal powers must be kept equal.
This implies a strong and constantly operating check on population from the difficulty of subsistence. This difficulty must fall somewhere; and must necessarily be severely felt by a large portion of mankind.
That population cannot increase without the means of subsistence, is a proposition so evident, that it needs no illustration. That population does invariably increase, where there are the means of subsistence, the history of every people that have ever existed will abundantly prove. And, that the superior power of population cannot be checked, without producing misery or vice, the ample portion of these too bitter ingredients in the cup of human life, and the continuance of the physical causes that seem to have produced them, bear too convincing a testimony.
This natural inequality of the two powers of population, and of production in the earth, and that great law of our nature which must constantly keep their effects equal, form the great difficulty that to me appears insurmountable in the way to the perfectibility of society. All other arguments are of slight and subordinate consideration in comparison of this. I see no way by which man can escape from the weight of this law which pervades all animated nature. No fancied equality, no agrarian regulations in their utmost extent, could remove the pressure of it even for a single century. And it appears, therefore, to be decisive against the possible existence of a society, all the members of which, should live in ease, happiness, and comparative leisure; and feel no anxiety about providing the means of subsistence for themselves and families.
In 1970, latter-day Malthusians in the Club of Rome think tank commissioned MIT researchers to construct a mathematical model of how population growth interacted with four other parameters describing a world system: industrialization, pollution, food production and resource depletion. The researchers – Donella Meadows, Jorgen Randers, Dennis Meadows, and William Behrens III – used their model to examine a variety of possible future scenarios for population growth. Exponential population growth was shown to quickly overwhelm linear growth in resources, as Rev. Malthus claimed.
Most scenario outcomes foretold misery and deprivation: spiking population was followed by collapse and eventual oscillation about a diminished population level sustained by the damaged resources of a depleted Earth. (The movie The Road Warrior depicted one of the more gloomy scenarios.) The range of model outcomes was summarized in the 1972 book Limits to Growth, which made the bestseller lists and provoked a noisy backlash from conservative scientists. oil executives, and pro-growth politicians.
The research was revisited and expanded in 2002 and summarized in A Synopsis of Limits to Growth: The 30 year update by Donella Meadows, Jorgen Randers, and Dennis Meadows. Population overshoot, collapse, and oscillation were still prominent in their scenario outcomes, but the time scale had contracted. Horrible things were fast approaching. Their conclusions:
Using the World3 computer model, Limits to Growth: The 30-Year Update presents 10 different scenarios for the future, through the year 2100. In each scenario a few numbers are changed to test different estimates of "real world" parameters, or to incorporate optimistic predictions about the development of technology, or to see what happens if the world chooses different policies, ethics, or goals. Most of the scenarios presented in Limits result in overshoot and collapse – through depletion of resources, food shortages, industrial decline or some combination of these or other factors.
Under the "business as usual scenario," world society proceeds in a traditional manner without major deviation from the policies pursued during most of the 20th century. In this scenario, society proceeds as long as possible without major policy change. Population rises to more than seven billion by 2030. But a few decades into the 21st century, growth of the economy stops and reverses abruptly.
As natural resources become harder to obtain, capital is diverted to extracting more of them. This leaves less capital for investment in industrial output. The result is industrial decline, which forces declines in the service and agricultural sectors. About the year 2030, population peaks and begins to decrease as the death rate is driven upward by lack of food and health services.
Upon reading these sobering words, I find myself performing an ignoble mental calculation and thinking, "Yes, tough luck indeed for the human race, but the next twenty years should be relatively good. That gets me almost to my 80th birthday. And various stopgaps and compensations will surely be made along the way, such that the inevitable collapse will likely be delayed until after 2050. I won't be around to face it."
This kind of selfish attitude is nothing new, of course. Consider 2 Kings 20:16-19:
Then Isaiah said to Hezekiah, "Hear the word of the Lord: The time will surely come when everything in your palace, and all that your fathers have stored up until this day, will be carried off to Babylon. Nothing will be left, says the Lord. And some of your descendants, your own flesh and blood, that will be born to you, will be taken away, and they will become eunuchs in the palace of the king of Babylon."
"The word of the Lord you have spoken is good," Hezekiah replied. For he thought, "Will there not be peace and security in my lifetime?"
(I hope that I am not misreading this passage and unfairly bringing Hezekiah down to my level.)