Land, energy and water: the constraints governing ideal U.S. population size
Pimental, D.; Pimental, M.
Npg Forum Series 1990: 1-6
1990
PMID: 12178968 Document Number: 328707
This document examines the constraints that are placed on US prosperity with increasing land, energy, and water usage. The report compares China and America and suggests that, if the US is not careful, our situation is headed toward the lack of prosperity found in China. US population is 246.1 million and we produce 47 times more goods and services (per capita) than the 1.1 billion people of China. This may be due to overpopulation contributing to diminished resources, food, natural forests, and increased erosion of the soil. Most of the resources we are currently using cannot be renewed after the next 100 years. Land area is diminishing, soil is eroding faster than replacement rates, 3 kcal of fossil fuel is expended to produce 1 kcal of food, natural gas is being depleted, oil supplies are limited to a 16 year supply, and groundwater is used faster than it can be replaced. Pollution (air, water, and soil) threatens these natural resources even more. The US must concentrate on the conversion from fossil fuel energy to solar energy, although much land is needed for solar energy systems. We may be able to increase our solar energy output 3-10 without affecting agriculture, and future fusion techniques may alleviate some of the fossil fuel pressures. Livestock manures could be used as fertilizers more often in order to decrease the waste of oil when synthetic fertilizers and pesticides are used. The ideal US population should be maintained at 40-100 million if we want to retain our current standard of living.