The recent rapid increase in human population over the past two entries has raised concerns that the planet may not be able to sustain present or larger numbers of inhabitants. Steve Jones, head of the biology department at University College London, has said, “Humans are 1 0,000 times more common than we should be”. Many environmental problems, such as rising levels of atmospheric carbon dioxide, global warming and pollution, are aggravated by the population expansion. Other problems associated with overpopulation include the increased demand for resources such as fresh water and food, starvation and malnutrition, consumption of natural sources faster than the rate of regeneration (such as fossil fuels), and a decrease in living conditions. However, some believe that waste and over- consumption, especially by wealthy nations, is putting more strain on the environment than overpopulation.
Limiting birth rates through legal regulations, educating people about family planning increasing access to birth control and contraception, and extraterrestrial settlement have been suggested as ways to mitigate overpopulation in the future. China and other nations already have regulations limiting the birth rate, with China using the one child policy. Contraception is a response to the fact that nearly 40% of pregnancies are unintended and that in the poorest regions mothers often lack information and the means to control the size of their families. History of concern Concern about overpopulation is relatively recent in origin. Throughout history, populations have grown slowly despite high birth rates, due to the population-reducing effects of war, plagues and high infant mortality.
During the 750 years before the Industrial Revolution, the world’s population increased very slowly, remaining under 250 million. By the beginning Of the 19th century, the world population had grown to a billion individuals, and intellectuals such as Thomas Malthusian and physiographic economists predicted that mankind would outgrow its available resources, since a finite amount of land was incapable of supporting an endlessly increasing population. Mercantilism argued that a large population was a form of wealth, which made it possible to create bigger markets and armies. Demographic transition and Sub-replacement fertility The theory of demographic transition held that, after the standard of living ND life expectancy increase, family sizes and birth rates decline. However, as new data has become available, it has been observed that after a certain level of development the fertility increases again.
This means that both the worry the theory generated about aging populations and the complacency it bred regarding the future environmental impact of population growth are misguided. Factors cited in the old theory included such social factors as later ages of marriage, the growing desire of many women in such settings to seek careers outside child rearing and domestic work, and the decreased deed of children in industrialized settings. The latter factor stems from the fact that children perform a great deal of work in small-scale agricultural societies, and work less in industrial ones; it has been cited to explain the decline in birth rates in industrialization regions. Another version of demographic transition is proposed by anthropologist Virginia Abernathy in her book Population Politics, where she claims that the demographic transition occurs primarily in nations where women enjoy a special status (see Fertility-opportunity theory). In strongly patriarchal nations, where she lams women enjoy few special rights, a high standard of living tends to result in population growth.
Fresh water. Water crisis Fresh water supplies, on which agriculture depends, are running low worldwide. This water crisis is only expected to worsen as the population increases. Potential problems with dependence on desalination are reviewed below, however, the majority of the world’s freshwater supply is contained in the polar icecaps, and underground river systems accessible through springs and wells. Fresh water can be obtained from salt water by desalination.
For example, Malta derives two thirds of its freshwater by desalination. A number of nuclear powered desalination plants exist; However, the high costs of desalination, especially for poor countries, make impractical the transport of large amounts of desalinated seawater to interiors of large countries. F-DOD Some scientists argue that there is enough food to support the world population, but critics dispute this, particularly if sustainability is taken into account. Africa In Africa, if current trends of soil degradation and population growth continue, the continent might be able to feed just 25% of its population by Hunger and malnutrition kill nearly 6 million children a year. In 2025.
2001, 46. 4% of people in sub-Sahara Africa were living in extreme poverty. Environment During a remarkably short period of time, we have lost a quarter of the world’s topsoil and a fifth of its agricultural land, altered the composition of the atmosphere profoundly, and destroyed a major proportion of our forests and other natural habitats without replacing them. Worst of all, we have driven the rate of biological extinction, the permanent loss of species, up several hundred times beyond its historical levels, and are threatened with he loss of a majority of all species by the end of the 21st century.