World population growth is increasing,and is already causing many problems. It is projected to continue growing in some parts of the world whilst others stabilise, with some estimates putting the final population of the world as high as 12 billion (it is currently half that).
Population growth brings with it many pressures. The environmental impacts are discussed below, however, there are many other effects of this rapid growth.
The main areas of rapid population growth are:
Asia, Africa and Latin America. These developing areas are moving through the demographic transition model from stage 2 to stage 3. In other words, during the second half of the 20th century their death rates fell, whilst the birth rates continued to be high. This was due to improving health care and sanitary conditions. As a result of the BR being so much higher than the DR, the population of these areas has exploded.
This population growth in the LEDC's could lead to a range of problems, which are listed below:
- Urban areas will become increasingly overcrowded. Shanty towns will continue to grow, and people living there will do so in very poor sanitary conditions, which may well cause outbreaks of devastating diseases. (For more information on shanty towns see the settlement topic).
- The increasing numbers of people in the cities will also cause more pollution and traffic congestion, leading to environmental problems and possibly diseases, or the increase of respiratory problems, such as asthma.
- More people will be in need of jobs, and so the problem of massive unemployment will occur. This could lead to more people being forced to live in poverty or turn to a life of crime.
- Governments may come under increasing pressure to provide adequate food and services to the increasing population. This may be beyond the current capability of many LEDC's, and may result in them borrowing more money from the MEDC's, thus increasing their debt problems.
- There may be an escalation of tensions between the MEDC's, who have sufficient resources and the LEDC's, who do not. In extreme circumstances this may lead to conflicts, as Malthus predicted (see below).
The main areas where there is little population growth are:
- The MEDC areas, such as Europe, North America and the Former Soviet Union. Most of these countries have already reached stage 4 of the demographic transition model, and in many cases have almost zero population growth. Some, such as France and Sweden may even be entering a fifth demographic stage where the DR is higher than the BR, meaning that the population falls.
- The drop in birth rates, as well as the increasing life expectancy of people in MEDC's, has led to problems in these countries also. Countries such as the UK, France and the United States over the next twenty years are going to have an ever increasing number of elderly people, over the age of 65. These countries are having to find strategies to cope with the extra demands that this will bring.
- As the percentage of elderly dependants increases, there will be less people of working age to support a larger dependant population. This could cause problems of a lack of sufficient people to fill available jobs in some areas.
- Health care resources will have to be increased to cope with the needs of the increasing elderly population. This may take money away from other important areas of society such as education or transport.
- The economic impact will be an increased need for funding for elderly health care, as well as an increase in the numbers of people getting pensions, and other economic benefits given to the elderly.
As the population of the world continues to grow at an ever increasing rate, the pressure on natural resources such as food and fuel also increases. In 1798 Thomas Malthus produced an interesting theory on how population and food resources might continue. He said that as the population continued to grow at a geometric rate, it would slowly catch up the food supply, which only grew arithmetically. This meant that at some point the food supply would not be enough to support the population and so the population would have to be curbed in some way. Malthus theorised that this would either be by policies to reduce the number of children being born, or by war, famine and disease.
In reality his theory hasn't occurred. In 1965 Esther Boserup put forward a different theory claiming that humans will develop new technologies to increase food production whenever they need to. This is because humans are the most resourceful animals on the planet, and so have developed new technologies and methods to cope with the increasing resource demands of a growing population.
Some of the technological advancements that she was referring to could include:
- The Agricultural Revolution, which included breeding cattle and sheep, which produced more milk, meat and wool. They also developed new technologies to evenly sow seeds, plough more efficiently and use their land more effectively.
- The Green Revolution. This introduced high yield seeds to developing world areas, such as India. The seeds could also be developed to cope with the drier conditions that they might experience in some of these areas.
- The introduction of irrigation systems into developing countries. Both large scale and small scale projects have been used to increase irrigation of crops in countries in Africa and Asia. Wells and canals are now commonly built to help communities to make the best use of their land.
- Better technology allowing more intensive farm yields. Faster growing plants varieties have allowed farmers to have two harvests a year from a single field. More effective fertilisers have meant that soil has been made more fertile.
- Genetically Modified crops could also prove to be one of these advancements, although they are in only the early stages of development at the moment.
In LEDC's rapid population growth has brought a number of problems, including:
- The destruction of large areas of rainforest, for use as farming land. This has particularly occurred in Brazil and in central Africa. The impacts of destruction like this, can not be easily calculated as it may well add the global warming problem.
- Farming areas are being put under increasing pressure, and are being over-used, either for crops or cattle. This is leading to a reduction in the nutrients available in the soil and to soil erosion, both of which mean the land is less likely to produce enough food.
- The increasing use of technologies such as fertilisers is causing problems of water pollution, which may endanger the lives of people who use the rivers for drinking water and for washing in.
Land Reclamation & Drainage: Countries,such as Japan and the Netherlands have tried to increase the land available for their growing urban areas by reclaiming land from the sea and draining marsh lands. Cities, such as Kobe in Japan now have large artificial islands that are used for industry, just off their waterfront. In the Netherlands a huge area to the East of Amsterdam has been reclaimed, using long dams to reclaim islands called Polders. Both ideas have been successful in allowing urban growth to continue on previously un-used areas.
In-Migration: Some developed countries have tried to boost their declining populations by encouraging the in-migration of migrant workers into their countries. A very good example is the Turkish "Gasterbeiters" (Guest Workers) who regularly moved into Germany during the 1980's and 1990's. They were encouraged to move in to the country for short periods to fill jobs that were not being taken up by Germans. However this scheme has slowed in recent years as it has begun to cost Germany a lot of money in benefits for Turks who have decided to stay, as well as jobs being lost due to global recession.
Birth control: The most famous example of a country using a birth control scheme is that of China. As the population sky-rocketed, the government realised that something had to be done otherwise there would be not enough resources to cope. In the 1970's and 1980's agricultural improvements meant that the country became self-sufficient and, most importantly, the country was producing the best balance of nutritious foods. However they also decided to " during the 1980's. This was aimed at slowing the rapid population growth that already taken the population of China over 1 billion.
Couples only having one child gained huge benefits such as free schooling for their child, tax incentives, better pensions, better access to state housing schemes and increased family allowances. All towns and villages had government appointed health workers, who made it their business to know when someone got pregnant. They would then help them through the pregnancy and put huge pressure on them not to have any more. There are huge social pressures not to have more than one child.
In general the scheme is working well in the urban areas, however in rural areas couples are still having large families to allow them to have workers for the farms. There are also reports of abortions and that baby girls have been killed by couples wanting one boy only.
Irrigation: Irrigation schemes have been vital in increasing the agricultural yields of many areas of the developing world. Small-scale schemes that benefit a community or village seem to be the most successful. The larger schemes that involve huge dams and the production of HEP often leave the country with huge debts to pay off, which often means they are even more dependent on MEDC's for help.