Overpopulation is a major cause of most of the world’s problems. Whether it is a question of food shortage, lack of drinking water or energy shortages, every country in the world is affected by it – or will be. Partly thanks to the import of goods from abroad, any particular country is able to maintain its own welfare. But this cannot go on in an unlimited way. The world population is threatening to rise from the current 7 billion to 11 billion according to the UN. There is a good chance that more and more countries will need their own products themselves. All continents except Africa have a total fertility rate around 2 children per woman, but Africa has an alarming total fertility rate around 4, which will result in an African population around 4.4 billion in 2100 from the current 1.3 billion if nothing is done. The African population boom is unsustainable and more action is needed to slow down the rapid population growth of Africa. If the problem won't be taken seriously enough by governments and other powerfull organisations, the result will be huge global environmental problems, terrorism, wars and massive global poverty everywhere. It will also harm the richest countries. Our planet can offer a quality of life comparable to that enjoyed in the European Union to no more than 3 billion people. With a population of 11 billion, welfare per person on a world scale will drop to that of a poor farmer who can scarcely provide sufficient food for himself and knows nothing of welfare. The climate is changing – and it matters little whether this can be blamed on human activity or on changes in the solar system. The sea level only has to rise slightly in order to cause a great deal of valuable agricultural land to disappear. Human beings have a tendency to want more and more welfare. World-wide the numbers of cars, planes and refrigerators are increasing before our very eyes. But there will come a time when population growth and welfare collide. There is a reasonably good chance that floods of people will trek all over the world searching for more food and welfare. Technicians are only too happy to point to technology that has solutions to all our problems up its sleeve. Unfortunately technical solutions have not as yet been able to combat world hunger in any significant way. Wherever there is no recognition or solving of the problems on a worldwide scale, war and violence would seem to be inevitable: Everyone wants to survive. The business world and the religions are generally only interested in population growth. Allowing welfare to shrink is often just as difficult for the rich as fleeing from poverty is for the poor. The only solution for the continuing population growth is more investments in the poorest regions of the world. Some African nations have decent total fertility rates, but in a large amount of African nations, women still have around 6 children on average, which is unsustainable. Some countries also have too low birth rates, like Singapore with a TFR around 1. A very fast population decline will also result in problems, a balanced total fertility rate between 1.5 and 2 is needed in every country for the best of the world. Education, especially for women, and free contraception helped a lot of poor countries with a rapid increase in living standards. Kenya did a great job for example with taking its population growth problems seriously. In the 1970s, they had a TFR of 8 and it is estimated to be 2.3 in 2020. They became one of the highest developed African countries. In countries with the highest birth rates, women often don't have the freedom to choose their amount of children, with social and religious pressure, lack of contraception and lack of education. The $2.5 billion "Family Planning 2020" project, which was founded by Bill and Melinda Gates, takes the population growth problem seriously and invested in a large amount of money in free contraception for the poorest regions of the world. This way, women will have more freedom in their choice for the amount of children they want, which is a great step forward. The next step for the poorest African countries in economic development can only be taken when their population growth will decline fast. Fortunately, a lot of African governments also started to take the problem seriously, but they often lack funds to have a huge impact. I hope governments and big organisations will invest more in Africa (especially free birth control and education) to decline its unsustainable rapid population growth.