[ed. note: Michael Jorrin, who I call Doc Gumshoe, is a longtime medical writer (not a doctor) who writes for us about medicine and health a couple times a month. He has agreed to our trading and disclosure restrictions, but does not generally write directly about investment ideas. His ideas, thoughts and words are his own, and you can see all his past pieces here.]
This is by no means a new concern. At the end of the 18th century, the Reverend Thomas Robert Malthus observed that population tended to grow at an exponential pace, while food supply grew only at an arithmetic pace. For example, if a thousand mating couples (2,000 individuals) had three offspring each, that would result in 3,000 children at the end of a generation, and 4,500 children at the end of two generations. In three generations, or about one century, that original population of 2,000 would have more than tripled to 6,750.
That’s more or less what has happened to global population in the past century. In fact, global population was estimated at about 2 billion in 1927, and is now somewhere around 7.5 billion, having passed the 7 billion mark in October 2010, about 12 years after it zoomed by the 6 billion marker. That’s closer to quadrupling in a century than to tripling.
However, the good Reverent Malthus thought that there would be offsetting factors that would prevent the planet from becoming impossibly overpopulated. Because food production could not conceivably keep up with the exponential pace of population growth, there would inevitably be famines. There would also be natural disasters, wars, and diseases. The Four Horsemen of the Apocalypse would keep the population in check.
Malthus was right about the exponential rate of population growth, but wrong about the factors that would offset that growth. Yes, there have been wars, natural disasters, and diseases, as well as famines, but it does not appear that those “Malthusian disasters,” as they are known, have had much effect on slowing population growth.
For example, the Chinese famine during the years 1959 to 1961 may have caused as many as 45 million deaths. (Recent conservative research puts the number at 36 million.) This does not seem to have slowed China’s increase in population by much. In 1959, Chinese population stood at 668 million, and it had increased to 682 million in 1960. Then, in 1961, due to the famine, it declined to 658 million. But by 1963 it had recovered all lost ground and increased to 691 million. The population of China passed the one billion mark in 1982, and now stands at 1.381 billion.
According to the UN’s Department of Economic and Social Affairs, global population is expected to hit 8.5 billion by 2030, 9.7 billion in 2050, and 11.2 billion by 2100. Those, by the way, are mid-range estimates. The high estimate for global population by 2100 is about 14 billion.
As of 2012, the UN’s projections for the regions of the world in 2100 were as follows:
|Latin America||0.69 billion|
|North America||0.57 billion|
This puts the total for the Western Hemisphere at around 1.26 billion, while the Eastern Hemisphere is projected to have a population of 8.84 billion. The largest increase is projected to take place in Africa, whose population of about 1 billion today is projected almost to quadruple. By 2050, the population of Nigeria is expected to top 400 million, exceeding that of the US, making it the third most populous country on the planet after India and China. And it’s projected to reach 760 million by the end of the century. India is expected to be the most populous country on earth, passing China in about five years.
The perils of population growth have been the basis for a good deal of dystopian fiction. I recall a story by Philip K. Dick in which office workers essentially lived in their workplace, sleeping in the stairwells, and subsisting on weird artificial foods. A staple was “chicken little,” an immense rapidly growing mass of an edible substance resembling chicken meat into which artificial nutrients were pumped, and which grew enormous volumes of “meat,” which were daily harvested and fed to the workers.
And currently some nervous members of the super-super rich are already in the process of establishing (or at least planning) totally self-contained and self-sufficient “environments,” in which all necessities for life could be generated, and which would protect them from the surrounding hordes. Farming and raising livestock would be carried out in perfectly climate-controlled indoor environments. Or perhaps their inhabitants could dispense with actual food – liquids containing all the necessary nutrients would keep them fit as a fiddle.
But those solutions are only for the privileged few.
Population: total numbers versus population density
Nigeria is not a tiny country, but if its population shoots up to the 400 million plus marker as expected, it’s going to be pretty crowded. Nigeria’s land area is about 357,000 square miles – less than one-tenth of the US land area of about 3.8 million square miles. And as for India, by 2050 it’s expected to have a population in the neighborhood of 1.7 billion crammed into a land area of 1.269 million square miles, less than one-third of the US land area. In each case, that comes out to a population density about ten times that of the US.
So, what are the effects of population density on health?
There are certain clear advantages to living in urbanized areas rather than out in the wonderful middle of nowhere. I am not speaking here of the Black Hole of Calcutta or the shanty-towns of Lagos or the favelas of Rio, but in general of the metropolitan areas of the world’s la