|Land Resources:||Arable Land
|Land Occupation & Policies:||Urbanization||Migrations||Policies|
Bibliographies provided by Cambridge Scientific Abstracts Environmental Route Net
How population effects the ways in which people use the land, its resources and the impact upon the quality of the land environment. The effects of different types of land use on human population levels, and the policy decisions and management actions that ameliorate the effects of population on land-use
LAND RESOURCES - Human populations are dependent on the resources of the lands to provide for food and shelter. Although with proper management land can be used sustainably and provide for future generations, unwise policies and practices can degrade lands and decrease productivity. This section emphasizes resources of managed lands such as agricultural lands and forests and the interaction of population with availability of resources.
Arable Land - In 1995, a total of 666 million acres of land were used for production of grain. This is 9% less than the historical peak of 732 million acres in 1981. Causes include conversion to non-farm uses such as housing, recreation and industrialization; failures of some formerly agricultural lands, soil erosion, and reductions in the amount of water available for irrigation. Per capita cropland has declined steadily worldwide from 0.23 hectares in 1950 to 0.13 ha in 1995 and is likely to continue to decline. This section provides information on the causes and implications of this with respect to human population.
Forestry and Deforestation - Forests once covered more than 40% of the earth's land surface. Already one-third of that area has been deforested so that forests only cover 27% of the land area (3.4 billion acres). In the 1980's, 9.95 million hectares (an area the size of South Korea) of forest were destroyed annually to expand agriculture, build cattle ranches, and to remove timber for human use. Almost all of this deforestation has occurred in the tropics. There is less than half the amount of forest per capita (0.5 ha) in the developing world than in industrialized countries (1.1 ha). Forest loss continues unabated. This section provides information on the causes and implications of this with respect to human population.
Desertification - The world's deserts expanded during the past decade due to climate change, soil erosion and poor land use practices. In addition, marginal land for agriculture has lost its ability to support plant life. This section provides information on the causes and implications of this with respect to human population.
LAND OCCUPATION, POLICIES & PRACTICES - This section looks at changing patterns of human settlements - urbanization and migration - and how population is both a cause and effect of changing settlement patterns.
Urbanization - Between 1950 and 1995, the numbers of urban residents increased by 250% while the numbers of rural residents increased by 75%. Now 2.58 billion people - 45% of the world's population - live in cities, compared with 29% in 1950. By 2005, the majority of the people will live in urban areas. Presently two-thirds of the urban residents were in developing countries, in contrast to 50% in 1970. Causes include industrialization, changes in agriculture and a variety of social and economic forces. Effects include poor health and impoverishment as well as a diversity of effects on the natural environment. This section provides information on the causes and implications of urbanization with respect to human population and environmental quality.
Migration - In addition to the rural - to - urban migration, people move from country to country and from region to region. At the end of 1994, there were 27.4 million refugees in the world, a number that has increased exponentially since the late 1970s. Population growth and environmental deterioration have been driving forces for much of this movement, which also has a number of consequences for future population growth and environmental repercussions.