In nature most organisms, i.e. animals and plants will produce huge numbers of offspring and yet their populations remain broadly constant. This is because huge numbers of the offspring die, mainly at an early stage. For example a single frog will produce thousands of tadpoles every year, but for the frog population to remain constant there can only be an average of two surviving young frogs for the whole lifetime of the two parents.
Human beings, like most mammals, do not produce the same vast numbers of offspring that lower animals and plants do, and there never was such huge mortality needed to maintain our population constant. However, even with quite high mortality in ancient times (especially of infants) our population has increased enormously since our species first evolved. In the modern world there is still less mortality. The only thing which prevents our population increasing vastly is that modern societies choose to exercise more control over their reproduction.
Dr Desmond Morris said in one of his early books (perhaps the Naked Ape) that when animals, such as rats for example, are overcrowded they will fight. I am not suggesting that human beings will start brawling the moment we find ourselves in a crowd, but when we are continually hindered by an excess of other people, and when this situation endures for long, we are likely to become impatient. We are likely to become less sympathetic to the interests of others.
Population grows according to the 'exponential law', that is the bigger it is, the faster it will grow. The world population is currently estimated to be 6 billion. It was about 1 billion in 1800. It is forecast to reach over 10 billion in 2050. This is made worse because people are also consuming more, and generally having a bigger impact on their environment, for example by travel. Not only are we more numerous, but in the developed countries each person is taking up more space. Whereas a hundred years ago, people lived with many family members in a small house, now we live in bigger houses with fewer people. We travel more, hence exerting impact and influence on our neighbours, and we consume far more.
In his book The Selfish Gene, Richard Dawkins picked a particularly high rate of population increase, that is that of Latin America in the 1970's. If the population continued to increase at the same rate, in 500 years the population would have to be packed in standing position over the whole area of the continent.
At the same time as we are placing ever increasing demands on the environment, the capacity for the world to go on sustaining this consumption is under threat.
It has been calculated that it is possible for world population to increase significantly and still be able to produce sufficient food. However this assumes much of the world's land and other resources being dedicated to food production. It also assumes that modern food production methods are used, yet we know that whenever science tries to defeat nature, nature will fight back and win in the end.
Probably the biggest limitation on the ability to produce food is the availability of water with which to irrigate crops. Then there is the problem of distribution. At the moment some human beings consume vastly more food than others. I have heard a statistic that approximately 1/3 of the world's population is overfed, 1/3 is underfed, and 1/3 is starving. If we were operating right on the limits of food production it would be necessary for everybody to have a more modest diet. Eating meat is a much less efficient way of using the world's food resources. Vegetable food is fed to animals, then we eat the animals, but for a given amount of food to us, meat production uses five times as much plant food as would be needed if we produced vegetarian food for our own consumption.
Our existing food production depends on fertilizers. One authority on the subject said that without fertilizers we could only sustain a population of 2 billion, whereas the actual population is 6 billion. These fertilizers are not sustainable. They are obtained from oil which is a finite resource and, quite apart from the effects on climate, oil will run out.
Not only that, but there are other pressures on our resources to grow crops. It has been said that bio-fuels might be the answer to global warming. The problem is that this will take away the ability to grow food crops, but also bio-fuels need fertilizer which comes from oil
Suppose we accept that food production and distribution can be improved to provide all the needs of mankind, what next? Population would go on increasing until once again there was insufficient food, or more likely, the other problems due to overcrowding would become significant first.
It must be necessary sooner or later for mankind to stop increasing its population.
So how far away is it before we start seeing problems? It's happening already. Clearly there are famines in the third world, sometimes due to drought, or otherwise due to wars or natural disasters. Even the civilized western world is not untouched. There were famines in England and Scotland in the years around the time of the plague and civil war. Then more recently was the Irish famine due to lack of potatoes around 1850. Notably this happened when Ireland was part of a prosperous Great Britain. In our present time the population of some species of fish such as cod are seriously under threat. Fish is the only remaining wild food eaten in quantity.
Politicians are aware of overcrowding of many parts of our society
The politician's answer is to keep saying that we must increase all these facilities. Nobody ever seems to say that we must reduce the population. This country is continuing to allow unrestricted immigration from the EU. These were not counted in the latest census and although the population of Britain is officially about 50 million, there might be another 20 million additional people uncounted.
Politicians like to see continual growth in the economy, but often this is just another way of saying growth of population. They have the idea that the only way retirement pensions can be paid is to keep increasing the working population. The problem is that increased working population will lead to a still greater number of old people in a few decades, so requiring a further increase in the working population. The logic is very similar to the logic of a chain letter, where each person pays out a small sum but receives payments from many more people. It works in theory so long as the number of people participating goes on increasing - something which is impossible in the longer term.
There is an idea that everything can be scaled up proportionately, thus as population increases there will be the same proportion of teachers, doctors, motor mechanics etc, so "what's the problem?". Well, we cannot think of the problem exclusively in terms of people. Some resources are finite and will not grow as the population grows. Land is the principal one. Land is not only finite it is FIXED.
Why not look at it another way, if the population was to reduce, all that wealth such as property and land which is in the hands of the older generation would become available for the use of a smaller number of people and their share would increase. After the plagues of the 16th and 17th century in England there was a large reduction in population. As a result land owners found agricultural workers in short supply and were forced to pay more. It became possible for working people to get more prosperity and obtain property and land for themselves.
Over-population means shortages and poverty.
When a population is increasing there will be proportionally more young people than there would otherwise be. Similarly, fewer old people. That is why some economists like to ensure the population is growing, so that the young working population will be large enough to support the non-working old people. However there is an important different aspect to this. The younger end of the population are also not working, and indeed their needs, because of education, are greater than the old. In fact there are probably more young non-working people than old. Therefore the argument works the other way round. If population is increasing there will be a greater number of non-working people at the young end of the scale. If population is decreasing the proportion of young people will reduce.
There is no doubt that education places a considerable burden on our society, though those who benefit from it, by being employed in the education industry (e.g. teachers), will deny it. In Britain we have local taxation in the form of council tax which funds local things. This tax is used to fund education (rightly or wrongly) and a full half of this local tax is used for education.
Most problems of the modern world are due to Man's excessive population, and could be solved it we would collectively stop increasing our population, and indeed allow it to decline somewhat.
Wars and conflicts. Sometimes due to competition for scarce resources such as land, food and water. Made worse by greed. Some conflicts are probably simply due to overcrowding resulting in people being unable to get some 'space'. The conflict and genocide in Rwanda in the mid 1990's did not seem to have any rational explanation. The two conflicting tribes were not even significantly different from each other.
Extinctions of wildlife. Destruction of the habitats needed by wild animals because of Man's need to accommodate his increasing population and consumption.
Pollution. There is much emphasis on the way we should live to reduce pollution, but the more people there are doing the polluting, the more pollution there will be. However environmentally friendly a person is, if he or she has an extra child, that will represent a whole lifetime of another person to add to problem.
In Britain these things are evident, but only in a minor way so far. Here the countryside is under threat, together with its wildlife. There are shortages of housing, and some species of fish in the North Sea are approaching extinction. Most of the recent population increase in Britain has been due to immigration which is a consequence of increased populations in other countries of the world. Even since beginning the writing of this page in early 2006 more news has come in to say that Britains population has increased further, and now passed 60 million. It is currently increasing faster than ever before.
This list includes things ranging from relatively minor discomforts and inconveniences to major problems which threaten the world, i.e. the well-being and even survival of mankind itself.
Many people are concerned about world issues such as climate change, nuclear power, animal welfare, threats to the countryside and wildlife. I sometimes find myself in conversation with them, usually as a result of their attempts to persuade me of their cause. I often mention my view that over-population is the underlying cause of all these problem and many agree, but it is surprising how so many say that nothing can be done.
The tax and benefit system is still paying people to have children. People are still getting fertility treatment on the NHS. International aid still concentrates on curing disease and saving lives but mostly does nothing to encourage population reductions through birth control.
In recent years a number of philanthropists and benefactors have emerged. Bill Gates, Bill Clinton, and anti-poverty activist Bob Geldof. Some have offered large amounts of money, others great personal effort, but they are all mostly concerned with saving lives and alleviating suffering, not tackling the fundamental problem of over population. Saving lives on its own will only allow empower people to reproduce and further increase in world population, so putting off the invevitable conseqences to a later time. We cannot force people of the world to exercise proper birth control, but when people have available large resources they should make their gift conditional on a long-term solution of reducing population or at least deterring further increase.
Britain cannot do much about the rest of the world, but at least we could take care of overpopulation in our own country. The consequence of this is that ultimately Britain might become a place which the rest of the world seeks to occupy. (It is now). We would have to drastically restrict immigration.
The Environment: environment.html
Farming and Food: farming.html
Nature and Wildlife: nature.html
The contents page for my environmental pages:
www.optimumpopulation.org - The Optimum Population Trust.
The direct address of this page is www.farthing.me.uk/world/population.html