Malthusian Myths


or

The Error of Population Control

 

Malthus

Reverend Thomas Robert Malthus (born 1766, Dorking, England) was a professor of Political Economy at Haileybury, England, a company.  He is most famous for his published work "An Essay on the Principle of Population ...," a rather long title that is more commonly referred to as "Essay on Population."  The rather verbose work started out at 50,000 words, and was revised to ultimately 250,000 words.  But it all can be be boiled down to a short proposition:

"population increases in a geometric ratio, while the means of subsistence increases in an arithmetic ratio."

"Through the animal and vegetable kingdoms, nature has scattered the seeds of life abroad with the most profuse and liberal hand. She has been comparatively sparing in the room, and the nourishment necessary to rear them... The race of plants, and race of animals shrink under this great restrictive law. And the race of man cannot, by any efforts of reason, escape from it. Among plants and animals its effects are waste of seed, sickness, and premature death. Among mankind, misery and vice. ...

For let the principles of Mr. Godwin's Enquiry14 and of other similar works be carried literally and completely into effect; let every corruption and abuse of power be entirely got rid of; let virtue, knowledge and civilization be advanced to the greatest height that these visionary reformers would suppose; let the passions and appetites be subjected to the utmost control of reason and influence of public opinion: grant them, in a word, all that they ask, and the more completely their views are realized, the sooner will they be overthrown again, and the more inevitable and fatal will be the catastrophe. For the principle of population will still prevail, and from the comfort, ease and plenty that will abound, will receive an increasing force and impetus. The number of mouths to be fed will have no limit; but the food that is to supply them cannot keep pace with the demand for it; we must come to a stop somewhere, even though each square yard, by extreme improvements in cultivation, could maintain its man. In this state of things there will be no remedy; the wholesome checks of vice and misery (which have hitherto kept this principle within bounds) will have been done away; the voice of reason will be unheard; the passions only will bear sway; famine, distress, havoc and dismay will spread around; hatred, violence, war and bloodshed will be the infallible consequence; and from the pinnacle of happiness, peace, refinement and social advantage we shall be hurled once more into a profounder abyss of misery, want, and barbarism that ever by the sole operation of the principle of population!"

Or, couched in other mathematical terms, population (otherwise unchecked) increases exponentially, while sustenance increases linearly.

We can illustrate this in graphic form in the chart below and to the right.

In the graph to the right, population (red line) is increasing exponentially up to point A, while food supply (green line) is increasing linearly. 

This depiction represents a new population from time zero to some point in time (A) where the natural environment cannot further increase food supply, and agriculture and farming are necessary to support additional population growth.

At Point B, the limit is reached to support a human population, and no further growth can be accommodated -- the food supply reaches a limit, (arable land and water) which does not support any further population growth.

Without further constraint, such a birth control, the population maintains a more or less constant level by infanticide, senicide, and some portion of the population starving.

First Counter Argument

Everything that humans eat are living things.  And every living thing also reproduces in a manner that produces an exponential population growth.  So our food supplies should be able to match our human population growth thru proper agricultural and farming practices.

 

Malthus answer

The animal food chain populations, to which all living things belong, are ultimately supported by a plant and microbe populations that depend on a dedicated surface area of minerals and soils.  The output of plant production cannot increase except by exploiting more surface area. Surface area exploitation (according to Malthus) is linear.  At some point, the surface are (for example, tillable land) is finite, and food supply becomes finite and fixed..

 

Natural Population Limiters

The natural population limiters are events that tend to be continually killing off segments of a population,  The traditional limiters of the human populations are the colloquially known as the four horsemen of the apocalypse -- War, famine, pestilence, and (natural) death.  We can add a few more -- natural disaster, chaos, and social breakdown.  Of these natural population limiters, Malthus was primarily concerned with starvation from famine, and quality of life.

When we look at primitive human populations, such as remote clans and tribes of hunter-gatherers -- those who live off the natural land, without much, if any, crop cultivation, they do indeed all seem to be small populations that are especially subject to the four horsemen -- and especially famine from drought. 

 

Assumption versus fact

Malthus made the observation that to increase crop yield required a proportionate increase in arable land -- for example, to double crop yield required the doubling of crop land.  That was an accurate observation at the time, and a given in his day, when one thin crop a year was the best expectation.

But it was only an assumption that it was some kind of immutable law. In fact, modern agricultural science has increased crop yield an order of magnitude since Malthus's time -- one acre of land today can produce ten times what the same acre in Mathus's time could produce.

Also, the world population has also increased an order of magnitude since the time of Malthus, from approximately 750 million, to 7 billion today.  All dire predictions of impending doom have proved false.  Today we produce far more food supply than we consume.  In fact, the worry among modern agriculture is price-destabilizing over-production, not under-production. 

 

Future Food Supply

There are still dire warning abounding everywhere of the imminent collapse of the world food supply.  And it is certain that primitive societies will still be victim to the vagaries of nature, and in particular, to the weather.  And political instability threatens some societies, which could seriously interrupt food supplies locally.

But the global food supply is sufficiently diversified and spread out to weather localized disturbances,  And there is no natural situation that modern societies cannot improve dramatically with  good engineering, such as dams, redirecting rivers, irrigation of deserts, and desalination of sea water.  As well as methods to produce multiple crops per year, and enclosures to  extend the growing season in cooler climates.  

And we are still primarily producing on a single horizontal surface. We have yet to fully exploit agriculture and farming on a vertical scale -- where growing beds are layered on top of each other.

 

2009-2012 Simon R Mouer III, PhD, PE
all rights reserved