According to an UN report, the global population will increase to 11 billion by the end of century and experts are worried that such rapid growth in Earth's population will make resources scarce, increase pollution, environmental damage, and lead to poverty, unemployment, crime, social and political unrest.
Approximately half of them will live in Africa, where the actual population of 1.2 billion is expected to rise to 5.6 billion. According to the UN report, it is a low probability of only 23% that the population growth will end this century. These predictions were made public during the 2015 Joint Statistical Meetings in Seattle..
John Wilmoth, the director of the United Nations Population Division, made public these predictions in Seattle, at the 2015 Joint Statistical Meetings, in a presentation called 'Populations Projections by the United Nations'. This was part of a larger session entitled 'Better Demographic Forecasts, Better Policy Decisions'.
The population of the United States is projected to increase at an average rate of 1.5 million per year until the end of the century. This will push the current U.S.' habitants count from 322 million to 450 million.
In Asia, where the current population is 4.4 billion, is numbers are expected to peak at 5.3 billion around the middle of the century, and then decline to around 4.9 billion.
The UN report examined the increase in population ageing in various countries, also studying using the potential support ratio (PSR). This represents the number of people aged between 20 and 64 divided by the number of people aged 65 and over. The potential support ratio is used to evaluate the number of workers per retiree.
The present situation finds Japan at the lowest PSR at 2.1. On the second place is Italy at a PSR of 2.6. In the US the median population age is expected to increase from 38 years today to 44.7 years by 2100. On the list of countries that will experience sharp PSR declines by the end of the century are included Mexico, 1.4 down from 8.7, China, from 7.1 to 1.4, and Germany, from 2.9 to 1.4.
By the end of the century only five countries are projected to have a PSR above 5.0: Somalia, Niger, Nigeria, Angola and Gambia. Among the African countries, Niger is expected to have the highest PSR by 2100, at 6.5.
According to director Wilmoth there is considerable uncertainty about these future trends, however there is a 90% chance that Nigeria's population will exceed 439 million people by the end of the century. This would be almost 2.5 times its current size.
Rapid population growth worries the experts and policy makes, since it can lead to a series of negative effects, including scarcity of resources, environmental damage, pollution, crime, poverty, unemployment and political unrest.
