Furthermore, particularly for agriculture, the development of these resources often involves a substantial land area. As a result, the relationship between the physical environment and human adaptations to that environment are clearly visible. Government plays an important role in this relationship by establishing controls on land use and agricultural production and by regulating the development of many resources. It is partly because processes inherent in urbanization and industrialization lead to high demand for raw materials that the United States has become dependent on imported raw materials in spite of great natural resource abundance. And modern machines are fueled by inanimate energy sources.
Mobility also implies heavy use of energy resources.
High income spread somewhat evenly among a large share of the population will generate high product demand. All this increases energy consumption. Americans consume about 25 percent of the world's total energy production. The United States imports half the petroleum it consumes, an increasing share of the iron ore and natural gas used, nearly all of its tin and aluminum, and large quantities of many other mineral ores. High income also affects diet.