Apart from two anomalies, fast declining birth rates suggest that world over-population is now destined for stabilisation and then decline.
One anomaly is that the present population of 7.4 billion contains a ‘plug’ of about 3 to 4 billion people who, 30 or 40 years ago, would have died long before old age. This would have enabled the present world population to be already poised to decline. Today, we have to wait a little longer.
The second anomaly is that of Africa. So far, the continent is such a dysfunctional mess that it is impervious to the changing birth rates in the rest of the world. This means that the present population of about 1 billion will, other things being equal, rise to 3 or even 4 billion all by itself in the next 30 years or so.
But Nature never — ever — tolerates an overlarge population without forcing some change. Of the traditional Four Horseman of the Apocalypse — starvation, warfare, death and disease — the first three already have marginal effects. The fourth has yet to happen to any significant extent.
The outbreak of Ebola last year has given us indications already of what could happen in Africa — and would have happened unless Western governments, medical charities and academic researchers had not piled in to help.
Africa, containing a large equatorial region in which mutations of viruses and bacteria proceed at a faster rate than in temperate and cold parts of the world, will continue to generate Ebola-type diseases regularly. The next time, however — and in succeeding times — the West, after weary years of fending off would-be African migrants into Europe, is highly likely not to help as it did with Ebola, but simply to quarantine Africa until the epidemic has its way.