A simple example of carrying capacity is the number of people who could survive in a lifeboat after a shipwreck. Their survival depends on how much food and water they have, how much each person eats and drinks each day, and how many days they are afloat.
Simply so, what is the earth's carrying capacity for humans?
Carrying capacity is not a fixed number. Estimates put Earth's carrying capacity at anywhere between 2 billion and 40 billion people [source: McConeghy]. It varies with a wide range of factors, most of them fitting under the umbrella of "lifestyle."
Is the world becoming overpopulated?
Most contemporary estimates for the carrying capacity of the Earth under existing conditions are between 4 billion and 16 billion. Depending on which estimate is used, human overpopulation may or may not have already occurred. Nevertheless, the rapid recent increase in human population is causing some concern.
What is the carrying capacity of the United States?
The Earth's limited supply of natural resources will only be able to sustain 2 billion humans by 2100, bad news for a world that already feeds 5.9 billion. The optimum human population, or carrying capacity, for the U.S. is projected to be 200 million, which is millions fewer than the current population.