World population has grown very rapidly after the first billion was reached in 1825. After that, as shown in text-fig1, it took 100 years to add the second billion (1825 – 1930), 30 years to add the third billion (1930 – 1960), 15 years to add the fourth one (1960 – 1975), 12 years to add the fifth one (1975 – 1987), 12 years to add the sixth billion (1987 – 1999). Currently, the world population number equals to 6,5 billion people. Global population is growing rapidly: last year it grew by almost 80 billion people, while 3 billion people are entering in their reproductive years. Up to 95 % of population growth is taking place in LEDCs.However, the world popu- lation growth is going to stabilize at 9,1 billion by around 2050 – 2080. This big and rapid increase in population number will create many challenges to the world: in fact, it will create a great pressure on governments that have to provide for their people, issues to the environment because more cities and industries will be needed, the risk of famine and malnutrition will increase. Highest growth rate are found in Africa, while lowest growth rate are found in Europe and North America.
Currently, developing countries have higher birth rates than developed countries; this is one of the reasons why the world population is located mainly in LEDCs. Developing countries have higher birth rates because of: • A greater population base;
• Many parents will decide tu have many children because of the infant mortality rate; • Workers are needed in the farms and children represent a source; • Cultural and religious factors;
On the other hand, developed countries have lower birth rates because of: • It’s expensive to look after large families;
• More women decide to concentrate on their job;