Robert Malthus and the Irish Potato

In 1798 Robert Malthus published a book entitled, An Essay on the Principle of Population.

As I understood it, the principle stated populations of humans grew in number until food became too scarce to sustain further growth. At this point people were able to stay alive, but just barely. Anything that reduced food production caused starvation until the population dropped to the level the amount of food available could sustain, again just barely. Making the problem worse, he maintained, was that the food supply can only increase arithmetically (1, 2, 3, 4…) while populations grow geometrically (2, 4, 8, 16…).

In everyday terms, Malthus’s Theory states that the population rises to the level of sustainability. Increase the amount of food the population rises, decrease the amount of food and the numbers of people drops.

An example is the potato famine in Ireland.

Around 1590 the potato was introduced to Ireland. By the 1800’s the potato had become the staple crop of the poor with approximately 3 million subsisting on it alone. This was possible because the potato is rich in protein, carbohydrate, minerals, and vitamins including vitamin C. So, while a boring diet, it was nevertheless a healthy one. The Irish poor subsisting on the potato were healthier than the British poor living mainly on bread. The danger for the Irish poor was that the potato increased the food supply and as a result the population doubled from 4 million to 8 million. A large segment of the Irish population was now dependent on a reliable potato crop. This dependency resulted in a disaster of colossal proportions.

In the year 1835, a disease struck the potato crop wiping it out entirely by 1837. Nearly one million starved. The Irish population dropped by 25% due to starvation, disease caused by malnutrition and by emigration, many to America where the food supply was more than adequate for the growing number of people.

This tragedy had been predicted by Malthus. The population had grown as the result of an increased food supply and when that food supply disappeared the population shrunk back to a number that could be sustained by the available food supply.

There is a lesson to be learned here for our rapidly growing world population. Feeding people is not the way to save lives, as the more you feed the more you have to feed until you simply cannot feed them all. Of course, we cannot let people starve as a way of helping them, but we must come up with some means of stabilizing our population. To my mind it is the greatest threat our planet faces. Nearly all the problems we face, energy shortages, food shortages, disease, war, pollution, and destruction of habitat are made worse by our rapidly growing population.

And despite what many say, this is not a problem technology can solve. Eventually old Robert is right.