Last week I attended another talk on demographic projections for 2050. A persuasive speaker (Mark Forman) impressed the audience with scary numbers about the probable increase in world population. So, let me clarify a few things.
The fear is that in the next 50 years the world population may rise to about 10 billion from the current 7 billion. This growth will be unequally spread around the globe, mostly adding to the 2.1 billion still living with less than $3.1 a day. Feeding all this people will deplete natural resources and seriously damage the environment. Equally scary, in rich countries, the rise in health care will increase life expectancy beyond 100 years, which, coupled with a drastic fall in birth rates and a rise in robotics, means that the ratio between retired people and employed workers will continue to increase. Meanwhile, lower qualified works may lose their jobs or will see them taken over by migrants.
These gloomy predictions may materialize or not, but even if they do happen they are not cause for panic. Let me explain why, one-by-one.
1) The danger of world famine. This is simply a repetition of Malthus erroneous conclusion in the XIX century and it is clearly misplaced since humanity has never lived in a world with so little hunger. Indeed, based on FAO estimates, if the increases in food production and productivity in the past 50 years (170%) are repeated in the next 50 years they will exceed by three times the forecasted rise in consumption. This is more than enough to feed the estimated two billion increase in population and still accumulate unnecessary stocks. Starting from a smaller base the growth in the recent past is more than enough to feed a much larger increase in population from two to seven billion inhabitants.
2) The depletion of nonrenewable resources, or its extensive use, like in the case of fossil fuels, will damage the environment to the point of making earth inhabitable. Again, history has shown that we can find new energy sources. For instance, just as humankind managed to replace coal by fossil fuels before we ran out of coal, we are also in the process of replacing these by electricity produced from solar and wind sources of energy before exhausting the fossil fuels.
3) Large scale migration will cause unemployment and bankrupt the welfare state. This is an old fear that history has repeatedly shown to be misplaced. Not only have mass migration flows been short lived, but they were also correlated with rising economic growth. Whether we consider ancient migrations during the Neolithic Revolution, the Indo-European expansion, and the Early Medieval Great Migrations or the recent flows to North and South America, or the contemporary flows within Europe the result has always been positive in economic terms. Of course these flows are not without turmoil, especially when they involve cultural shocks. Nevertheless, even at the cultural level, the rise of a global culture resulting from globalization at the level of the media and international travel will reduce cultural barriers.
4) Robots will replace humans causing mass unemployment. This is the same argument that led some workers to destroy machines at the start of the industrial revolution fearful of losing their jobs of 15 and 16 hours per day, including children. Many now work only 5 days a week and less than 8 hours per day and the feared massive unemployment did not materialize. It is foreseeable that robotics will facilitate longer education, longer holidays, and shorter weeks and days which will facilitate the employment of everybody for a long time. The possibility that robots might one day replace humans in most jobs is a welcoming evolution, since most humans can find better things to do than work. Still, such it is still too far away to be considered a threat.
5) An aging population is a time bomb since there are not enough babies being born and the ratio between pensioners and workers is increasing dangerously. In what concerns the risk of a pension time bomb I have written a post explaining why it is unfounded and easily overcome by past levels of productivity growth. The possibility of an inverted age pyramid is real but it is not a threat. Indeed, it will delay the replacement of humans by robots because the care for the elderly is more labor-intensive than other jobs performed by humans. All we will need is to adapt to a society with more elders than youngsters. But, humankind is eminently adaptable.
So, whatever way we look at the so-called demographic threat there is no reason to fear the future. With the right policies and transition periods all the frictions caused by demographic shifts can be solved, as long as people disregard the ignorance or malfeasance of the prophets of doom.
This is not to say that there no threats to humankind. There are certainly external threats, like the celestial bodies who destroyed the dinosaurs, as well as man-made dangers. The later may be accidental (e.g. result from scientific experiments) or may be caused by the evil use of weapons of mass destruction. Technical advances in space technology may help us avoid the fate of the dinosaurs while careful science monitoring may prevent scientific accidents.
Indeed, where humanity runs the risk of not progressing enough is in organizing society to stop evil or mad leaders from using arms of mass destruction.
All in all, as long as humans violent forms of conflict resolution, we have more reasons to be optimistic than pessimistic about the future of humankind. Such conflicts are the true threat to the humankind not demography.