Reflections on recent events, plus the occasional fact
free rant unfiltered by rational argument.
“Population Explosion” scream the headlines. “Too many people are overburdening the planet, and we are heading for disaster.” That’s the dominant narrative: environmentalists, politicians and every ‘Johnny with a cause’ spout this line. After all the United Nations told us on 31 October 2011, the planet was home to seven billion people. That’s up from 1.6 billion in 1900. We need to get a grip and sort this out.
Poverty, pollution, instability and wars are all blamed on overpopulation. The ‘save the planet’ crowd allied to the ‘global warming pundits’ are the most vocal. Brandishing their data on power-points, they make a grand living jetting about telling us how to conduct our lives. The problem is these folks are wrong about population growth. Here’s why.
For most of recorded history, and as far as we can tell, the human population growth rate per annum was less than one per cent. I know the data is dodgy the further back we go, but that’s not a significant concern. It's modern trends we need to consider.
After World War I, fertility rates (how many children each woman has) went up. The population growth rates climbed to reach about four per cent in 1970. Only the great Chinese famine and World War II saw temporary downward moves. It’s important to understand that a two per cent annual increase in population compounds to give a doubling every 35 years.
The growth we’ve seen over the past 100 odd years is rapid and unprecedented. Moreover, in case you hadn’t noticed its stopped. The data is clear. The worldwide population birth rate peaked around 1990. It’s now going down.
Wait a minute I hear you cry! Why is the population of the world still increasing when births are falling? The answer is simple. Deliveries don't cause the continued growth, but a lack of deaths. People are living longer. At the same time, children are surviving childbirth and the delicate infant years. All these combine to keep the population up for the time being.
Forecasters observe counter-intuitive factors that have a bearing on how the numbers may change. For example, birth rates are higher when child death rates are higher. This applies to rich and developing countries. Added to that is wars, famine and epidemics spur greater population growth in the longer term. This phenomenon appears to function to ensure the species survives. Thus, if we can prevent and avoid disasters, we help stabilise the number of children born. That’s already happening.
Anti-malaria campaigns have prevented an estimated 6.5 million deaths, many of these are children. When fewer children die, parents have less compunction to add more children. Today 100 countries have eliminated malaria. In turn, this led to a corresponding drop in fertility rates. It’s as if that anti-malaria net you sponsored is a secondary birth control device. Don’t tell the Catholic Church.
To sustain a population, as a rough figure, each woman needs to give birth to 2.1 children. That’s assuming no flu epidemic or war comes along to wipe out millions. Once again, because of compounding, even small changes in fertility or death rates cause big swings in population numbers.
Forecasting is a tricky business because it involves a degree of subjectivity and making a few assumptions. Also in play are external factors. Singapore as a new nation in the 1970s wanted to understand and plan for its projected population. The demography guys got to work to predict 80,000 births a year by 2000. The reality was 38,000. Policymakers struggled to recognise that the models used to predict future numbers are weak at best and misleading at worst. No one understood that as society evolved upward, then fertility declined. That’s now obvious.
There is some data we can rely on, and it points to trends that are likely; not certain, but likely. In 1960 the average was five children per woman worldwide. These days that’s fallen to 2.5 children per woman, and the trend line appears to continue on a downward trek. While some nations have seen rises in fertility rates, this comes from new young migrants having kids. These changes are not intrinsic to the country nor sustained.
The scientists agree that the population explosion has fizzled out in the rich and developing countries. Moreover, the evidence suggests the population will either stabilise or decline.
Already we see the signs. Major urban centres such as Liverpool, Glasgow, Rostock and Detroit are experiencing de-population. These cities relied on migration to sustain their numbers. As this dries up, the life-blood ebbs from the city. We can expect more of this if the fertility rates continue to fall.
We can point to factors causing the fall in fertility. Female empowerment through the pill, better education, economic influences and culture all play a part.
The consequence of fewer people is a double-edged sword. Some are pessimistic, yet there is an optimistic side. Indeed, it should reduce the pressure on the resources of the planet assuming we don’t use more stuff. But, many of our current economic models work on growth in numbers and consumption. That will need to change. Further, it is not fewer people but also more people living longer.
The rich western nations currently moving towards curtailing migration may have to change course. With shrinking populations, who will do the menial jobs and staff the old folks homes? Who will run the hospitals? Food for thought.
As I’ve shown forecasting is a tricky business. The best data we have indicates that by 2100 we may see the population of the world peak at around 10 billion. After that, a decline may set in, although how far it goes is anyone’s guess. However, with low rates of childbirth, the population drops to 6.2 billion and keeps moving downward.
Of course, we could be completely wrong. All those ladies pushing dogs around in prams may suddenly switch track and get a boyfriend. Then all bets are off. Still, my hunch is dog pram makers have an excellent future.
Walter De Havilland was one of the last of the colonial coppers. He served 35 years in the Royal Hong Kong Police and Hong Kong Police Force. He's long retired.