Why will no one talk about the elephant in the room that is population? Previously because it used to be taboo – but now perhaps because it is no longer one of the key issues that faces our civilisation. The population boom is about to end one way or another. Let me explain.

Ever since Thomas Malthus outlined his theory on the inability of the human race to feed its growing population, people have been concerned about the re-emergence of the famines and starvation that have dominated much of human existence.

Whilst it is indeed true that food prices have risen substantially, they will rise again as our ability to produce more food is not matched by the increase in our population. This may lead to societal crises but managing food waste and distribution, as well as new agricultural technology, can probably help us feed our peak population.

It is also true that our overuse of antibiotics has led to more and more resistant strains of disease. One third of all antibiotics that are produced in the world are used as a preventive measure in mass-produced chicken. This abusive malpractice could easily unleash a Spanish flu type epidemic that in 1918 killed more people than World War I, some estimates range as high as 5% of the global population.

What few people realise, however, is that what we call modern civilisation is the cure to overpopulation at that time.

If every woman in her lifetime has 2.1 children, the world’s population would stay roughly flat. In Europe that birthrate figure has fallen to around 1.4 children on average. That means that if nothing else happened, and there were no migration, Europe’s population would divide by three by the year 2100.

Those countries whose already large populations are rapidly growing, such as Pakistan and Nigeria, have birthrates as high as 2.6 children per woman. This implies that the populations of those countries will more than double over the next 30 to 40 years. Such is the effect of small variances around the magic birthrate number 2.1.

If you delve deep into the numbers behind the childbirth rates in those countries, you see a remarkable and different emerging picture. In the countryside the birth rate in many regions is over 4.5 children per woman, suggesting a huge boom in population in those countries.

However, in 2006 we passed the point at which 50% of all humans lived in cities, up from 4% in the pre-industrial era. It is forecast that by 2050 nearly 80% of all humanity will live in cities and their slums.

In the major cities of those high-population growth countries, the birthrates average 1.1 children per woman during her lifetime. This birthrate would imply that the populations of humans on this planet will fall dramatically over the next 80 years just from our lower birth rates, not to mention the impact of birth protection hormones in our water systems and wider availability of reproductive health services.

The reason behind this is that in the countryside children tend as to add to economic the activity of the family. In cities children are expensive to provide for and tend to detract from a families economic activity. It may well be that cities, in which ever more of us are living, are the only effective form of contraception that mankind has ever invented.

As a society we are reluctant to talk about the over populating of our planet by humans, whereas we are quite happy to talk about overpopulation of other animals as a pest or a plague!

This keeps us from hearing and understanding the good news and that we should focus on other issues with more energy rather than just population. One of these of course is how we feed the peak population of between 9 and 11 billion without causing the collapse of civilisation as strained food systems have caused the collapse of civilisation before us.