state in which a human population can survive indefinitely

used 355 billion gallons of freshwater, over 1,000 gallons (4,000 liters) per person per day. Biologically, an adult human needs less than 1 gallon of water daily. These data alone suggest the Earth can support at most one-fifth of the present population, 1.5 billion people, at an American standard of living.Ī man works recycling plastic bottles outside Hanoi, Vietnam. The average American uses about 9.7 hectares. As a fiscal analogy, we live as if our savings account balance were steady income.Īccording to the Worldwatch Institute, an environmental think tank, the Earth has 1.9 hectares of land per person for growing food and textiles for clothing, supplying wood and absorbing waste. Wealthy countries consume out of proportion to their populations. Humans are consuming and polluting resources – aquifers and ice caps, fertile soil, forests, fisheries and oceans – accumulated over geological time, tens of thousands of years or longer. This anticipated leveling off signals a harsh biological reality: Human population is being curtailed by the Earth’s carrying capacity, the population at which premature death by starvation and disease balances the birth rate. On the other hand, world numbers are projected to reach 8 billion around 2023, a doubling time of 49 years, and barring the unforeseen, expected to level off around 10 to 12 billion by 2100. Humans reached 1 billion around 1800, a doubling time of about 300 years 2 billion in 1927, a doubling time of 127 years and 4 billion in 1974, a doubling time of 47 years.

Real population growthįor real populations, doubling time is not constant. The 43rd payment, on July 1, 2022, just short of $88 billion and equal to all the preceding payments together (plus one penny), breaks the bank. After three years, $687,194,767.35, or about one week of Bezos’ 2017 income.

After two years, $167,772.15 – substantial, but paltry to a billionaire. How long would his $100 billion fortune uphold the contract? Take a moment to ponder and guess.Īfter one year, or 12 payments, your total contract receipts come to US$40.95, equivalent to a night at the movies. 1, four on March 1, and so forth, with the payment doubling each month. To illustrate, suppose Jeff Bezos agreed to give you one penny on Jan. Exponential growth tends to start slowly, sneaking up before ballooning in just a few doublings.

State in which a human population can survive indefinitely