Saturday, September 24, 2011

Complacency and global population growth

An editorial in the Irish Times today (Saturday 24th Sept 2011) notes that, this month, a birth somewhere in the world was responsible for “…tipping the global population over the seven billion mark. Up from a paltry billion in 1804, a mere two billion in 1927, and five billion in 1987”. The piece then goes on to remark, in effect, that Robert Malthus was wrong. This Anglican clergyman postulated that, as population growth is exponential and food production increases only according to an arithmetic progression, the growth in numbers of humans would eventually outstrip the ability of the planet to feed everyone. The Irish Times’s conclusion is based on the assertion that “The world population may have quadrupled in the 20th century, but the calories available per person went up, not down”.

There’s a lot that is wrong with this analysis. Claiming only that the number of people has quadrupled in the 20th century is to totally ignore, or be ignorant of the fact, that growth even as described in the article is indeed exponential. Therefore Malthus got that part of his calculation right. As for the rest, his failure to foresee certain advances in science, agriculture and food technology may only mean that he got his timing wrong, not that the basic thesis was incorrect. The world is after all, as it was in his day, a finite entity.

Something else that Malthus could not have foreseen is the development and growth of birth control. In the Western world this has achieved such as state of acceptance and practice that population rise due to live births hardly exists at all. One interesting exception is here in Ireland. However, we can afford the highest birthrate in the EU because our population density is way below the average. In the USA, growth is almost entirely due to immigration, much of it illegal. China has taken drastic steps to control its population, such as attempting to limit families to a single child and making abortion a government promoted means of supplementing other forms of birth control.

So the population growth that is taking place is in underdeveloped regions – the very areas that can least accommodate it. For this reason, as also noted, life expectancy is low. Most importantly, for the memory of Malthus, this is all too often due to famine or the effects of malnutrition, which is obviously much the same thing.

It does not become us to be too complacent about population growth.

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