AuthorTopic: Official Population Overshoot Thread  (Read 3555 times)

Offline RE

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🌍 7.5 billion and counting: How many humans can the Earth support?
« Reply #15 on: July 12, 2018, 02:35:43 AM »
https://theconversation.com/7-5-billion-and-counting-how-many-humans-can-the-earth-support-98797

7.5 billion and counting: How many humans can the Earth support?
July 9, 2018 6.28am EDT


Humans are the most populous large mammal on Earth today, and probably in all of geological history. This World Population Day, humans number in the vicinity of 7.5 to 7.6 billion individuals.

Can the Earth support this many people indefinitely? What will happen if we do nothing to manage future population growth and total resource use? These complex questions are ecological, political, ethical – and urgent. Simple mathematics shows why, shedding light on our species’ ecological footprint.
The mathematics of population growth

In an environment with unlimited natural resources, population size grows exponentially. One characteristic feature of exponential growth is the time a population takes to double in size.

Exponential growth tends to start slowly, sneaking up before ballooning in just a few doublings.

To illustrate, suppose Jeff Bezos agreed to give you one penny on Jan. 1, 2019, two pennies on Feb. 1, four on March 1, and so forth, with the payment doubling each month. How long would his $100 billion fortune uphold the contract? Take a moment to ponder and guess.

After one year, or 12 payments, your total contract receipts come to US$40.95, equivalent to a night at the movies. After two years, $167,772.15 – substantial, but paltry to a billionaire. After three years, $687,194,767.35, or about one week of Bezos’ 2017 income.

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.
Real population growth

For real populations, doubling time is not constant. 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.

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.

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.

Ecological implications

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.

Wealthy countries consume out of proportion to their populations. As a fiscal analogy, we live as if our savings account balance were steady income.

According 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. The average American uses about 9.7 hectares.

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.
A man works recycling plastic bottles outside Hanoi, Vietnam. REUTERS/Kham

Water is vital. Biologically, an adult human needs less than 1 gallon of water daily. In 2010, the U.S. used 355 billion gallons of freshwater, over 1,000 gallons (4,000 liters) per person per day. Half was used to generate electricity, one-third for irrigation, and roughly one-tenth for household use: flushing toilets, washing clothes and dishes, and watering lawns.

If 7.5 billion people consumed water at American levels, world usage would top 10,000 cubic kilometers per year. Total world supply – freshwater lakes and rivers – is about 91,000 cubic kilometers.

World Health Organization figures show 2.1 billion people lack ready access to safe drinking water, and 4.5 billion lack managed sanitation. Even in industrialized countries, water sources can be contaminated with pathogens, fertilizer and insecticide runoff, heavy metals and fracking effluent.
Freedom to choose

Though the detailed future of the human species is impossible to predict, basic facts are certain. Water and food are immediate human necessities. Doubling food production would defer the problems of present-day birth rates by at most a few decades. The Earth supports industrialized standards of living only because we are drawing down the “savings account” of non-renewable resources, including fertile topsoil, drinkable water, forests, fisheries and petroleum.

The drive to reproduce is among the strongest desires, both for couples and for societies. How will humans reshape one of our most cherished expectations – “Be fruitful and multiply” – in the span of one generation? What will happen if present-day birth rates continue?

Population stays constant when couples have about two children who survive to reproductive age. In some parts of the developing world today, couples average three to six children.

We cannot wish natural resources into existence. Couples, however, have the freedom to choose how many children to have. Improvements in women’s rights, education and self-determination generally lead to lower birth rates.

As a mathematician, I believe reducing birth rates substantially is our best prospect for raising global standards of living. As a citizen, I believe nudging human behavior, by encouraging smaller families, is our most humane hope.
SAVE AS MANY AS YOU CAN

Offline Surly1

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TOP 20 LARGEST COUNTRIES BY POPULATION (LIVE)
« Reply #16 on: July 14, 2018, 07:32:07 AM »
On this site you can watch the world population clock tot up births I n real time as we rush toward the Seneca cliff of population overshoot. China and India tip the scales at a billion and change, and the US is third with 326M.

Interesting site. Follow the link for much, much more including growth rates, forecasts, etc..

TOP 20 LARGEST COUNTRIES BY POPULATION (LIVE)

TOP 20 LARGEST COUNTRIES BY POPULATION (LIVE)

1 China1,415,248,554
2 India1,354,598,933
3 U.S.A.326,851,451
4 Indonesia266,898,088
5 Brazil210,925,959
6 Pakistan200,954,109
7 Nigeria196,060,166
8 Bangladesh166,430,601
9 Russia143,963,793
10 Mexico130,817,815
11 Japan127,174,404
12 Ethiopia107,630,346
13 Philippines106,570,833
14 Egypt99,443,047
15 Vietnam96,526,085
16 D.R. Congo84,104,103
17 Germany82,300,020
18 Iran82,042,954
19 Turkey81,960,054
20 Thailand69,188,507

World Population: Past, Present, and Future

(move and expand the bar at the bottom of the chart to navigate through time)
World Population : 610000000  | July 01, 1700
300400500600700800900100011001200130014001500160017001800190020002100200000000040000000006000000000800000000010000000000
Datetime World Population
Jul 1, 200 190,000,000
Jul 1, 600 200,000,000
Jul 1, 700 210,000,000
Jul 1, 800 220,000,000
Jul 1, 900 240,000,000
Jul 1, 1000 275,000,000
Jul 1, 1100 320,000,000
Jul 1, 1200 360,000,000
Jul 1, 1400 350,000,000
Jul 1, 1500 450,000,000
Jul 1, 1650 500,000,000
Jul 1, 1700 610,000,000
Jul 1, 1760 770,000,000
Aug 1, 1804 1,000,000,000
Jul 1, 1850 1,200,000,000
Jul 1, 1900 1,600,000,000
Jul 1, 1927 2,000,000,000
Jul 1, 1950 2,536,274,721
Jul 1, 1951 2,583,816,786
Jul 1, 1952 2,630,584,384
Jul 1, 1953 2,677,230,358
Jul 1, 1954 2,724,302,468
Jul 1, 1955 2,772,242,535
Jul 1, 1956 2,821,383,444
Jul 1, 1957 2,871,952,278
Jul 1, 1958 2,924,081,243
Jul 1, 1959 2,977,824,686
Jul 1, 1960 3,033,212,527
Jul 1, 1961 3,090,305,279
Jul 1, 1962 3,149,244,245
Jul 1, 1963 3,210,271,352
Jul 1, 1964 3,273,670,772
Jul 1, 1965 3,339,592,688
Jul 1, 1966 3,408,121,405
Jul 1, 1967 3,479,053,821
Jul 1, 1968 3,551,880,700
Jul 1, 1969 3,625,905,514
Jul 1, 1970 3,700,577,650
Jul 1, 1971 3,775,790,900
Jul 1, 1972 3,851,545,181
Jul 1, 1973 3,927,538,695
Jul 20, 1974 4,000,000,000
Jul 1, 1975 4,079,087,198
Jul 1, 1976 4,154,287,594
Jul 1, 1977 4,229,201,257
Jul 1, 1978 4,304,377,112
Jul 1, 1979 4,380,585,755
Jul 1, 1980 4,458,411,534
Jul 1, 1981 4,537,845,777
Jul 1, 1982 4,618,776,168
Jul 1, 1983 4,701,530,843
Jul 1, 1984 4,786,483,862
Jul 1, 1985 4,873,781,796
Jul 1, 1986 4,963,633,228
Jul 11, 1987 5,000,000,000
Jul 1, 1988 5,148,556,956
Jul 1, 1989 5,240,735,117
Jul 1, 1990 5,330,943,460
Jul 1, 1991 5,418,758,803
Jul 1, 1992 5,504,401,149
Jul 1, 1993 5,588,094,837
Jul 1, 1994 5,670,319,703
Jul 1, 1995 5,751,474,416
Jul 1, 1996 5,831,565,020
Jul 1, 1997 5,910,566,295
Jul 1, 1998 5,988,846,103
Oct 12, 1999 6,000,000,000
Jul 1, 2000 6,145,006,989
Jul 1, 2001 6,223,412,158
Jul 1, 2002 6,302,149,639
Jul 1, 2003 6,381,408,987
Jul 1, 2004 6,461,370,865
Jul 1, 2005 6,542,159,383
Jul 1, 2006 6,623,847,913
Jul 1, 2007 6,706,418,593
Jul 1, 2008 6,789,771,253
Jul 1, 2009 6,873,741,054
Jul 1, 2010 6,958,169,159
Oct 31, 2011 7,000,000,000
Jul 1, 2012 7,128,176,935
Jul 1, 2013 7,213,426,452
Jul 1, 2013 7,213,426,452
Jul 1, 2014 7,298,453,033
Jul 1, 2014 7,298,453,033
Jul 1, 2015 7,383,008,820
Jul 1, 2015 7,383,008,820
Jul 1, 2016 7,466,964,280
Jul 1, 2016 7,466,964,280
Jul 1, 2017 7,550,262,101
Jul 1, 2018 7,632,819,325
Jul 1, 2019 7,714,576,923
Jul 1, 2020 7,795,482,309
Jul 1, 2025 8,185,613,757
Jul 1, 2030 8,551,198,644
Jul 1, 2035 8,892,701,940
Jul 1, 2040 9,210,337,004
Jul 1, 2045 9,504,209,572
Jul 1, 2050 9,771,822,753
Jul 1, 2060 10,222,598,469
Jul 1, 2070 10,575,846,551
Jul 1, 2080 10,848,708,184
Jul 1, 2090 11,050,055,193
Jul 1, 2100 11,184,367,721
30040050060070080090010001100120013001400150016001700180019002000
Datetime World Population
Jul 1, 200 190,000,000
Jul 1, 600 200,000,000
Jul 1, 700 210,000,000
Jul 1, 800 220,000,000
Jul 1, 900 240,000,000
Jul 1, 1000 275,000,000
Jul 1, 1100 320,000,000
Jul 1, 1200 360,000,000
Jul 1, 1400 350,000,000
Jul 1, 1500 450,000,000
Jul 1, 1650 500,000,000
Jul 1, 1700 610,000,000
Jul 1, 1760 770,000,000
Aug 1, 1804 1,000,000,000
Jul 1, 1850 1,200,000,000
Jul 1, 1900 1,600,000,000
Jul 1, 1927 2,000,000,000
Jul 1, 1950 2,536,274,721
Jul 1, 1951 2,583,816,786
Jul 1, 1952 2,630,584,384
Jul 1, 1953 2,677,230,358
Jul 1, 1954 2,724,302,468
Jul 1, 1955 2,772,242,535
Jul 1, 1956 2,821,383,444
Jul 1, 1957 2,871,952,278
Jul 1, 1958 2,924,081,243
Jul 1, 1959 2,977,824,686
Jul 1, 1960 3,033,212,527
Jul 1, 1961 3,090,305,279
Jul 1, 1962 3,149,244,245
Jul 1, 1963 3,210,271,352
Jul 1, 1964 3,273,670,772
Jul 1, 1965 3,339,592,688
Jul 1, 1966 3,408,121,405
Jul 1, 1967 3,479,053,821
Jul 1, 1968 3,551,880,700
Jul 1, 1969 3,625,905,514
Jul 1, 1970 3,700,577,650
Jul 1, 1971 3,775,790,900
Jul 1, 1972 3,851,545,181
Jul 1, 1973 3,927,538,695
Jul 20, 1974 4,000,000,000
Jul 1, 1975 4,079,087,198
Jul 1, 1976 4,154,287,594
Jul 1, 1977 4,229,201,257
Jul 1, 1978 4,304,377,112
Jul 1, 1979 4,380,585,755
Jul 1, 1980 4,458,411,534
Jul 1, 1981 4,537,845,777
Jul 1, 1982 4,618,776,168
Jul 1, 1983 4,701,530,843
Jul 1, 1984 4,786,483,862
Jul 1, 1985 4,873,781,796
Jul 1, 1986 4,963,633,228
Jul 11, 1987 5,000,000,000
Jul 1, 1988 5,148,556,956
Jul 1, 1989 5,240,735,117
Jul 1, 1990 5,330,943,460
Jul 1, 1991 5,418,758,803
Jul 1, 1992 5,504,401,149
Jul 1, 1993 5,588,094,837
Jul 1, 1994 5,670,319,703
Jul 1, 1995 5,751,474,416
Jul 1, 1996 5,831,565,020
Jul 1, 1997 5,910,566,295
Jul 1, 1998 5,988,846,103
Oct 12, 1999 6,000,000,000
Jul 1, 2000 6,145,006,989
Jul 1, 2001 6,223,412,158
Jul 1, 2002 6,302,149,639
Jul 1, 2003 6,381,408,987
Jul 1, 2004 6,461,370,865
Jul 1, 2005 6,542,159,383
Jul 1, 2006 6,623,847,913
Jul 1, 2007 6,706,418,593
Jul 1, 2008 6,789,771,253
Jul 1, 2009 6,873,741,054
Jul 1, 2010 6,958,169,159
Oct 31, 2011 7,000,000,000
Jul 1, 2012 7,128,176,935
Jul 1, 2013 7,213,426,452
Jul 1, 2013 7,213,426,452
Jul 1, 2014 7,298,453,033
Jul 1, 2014 7,298,453,033
Jul 1, 2015 7,383,008,820
Jul 1, 2015 7,383,008,820
Jul 1, 2016 7,466,964,280
Jul 1, 2016 7,466,964,280
Jul 1, 2017 7,550,262,101
Jul 1, 2018 7,632,819,325
Jul 1, 2019 7,714,576,923
Jul 1, 2020 7,795,482,309
Jul 1, 2025 8,185,613,757
Jul 1, 2030 8,551,198,644
Jul 1, 2035 8,892,701,940
Jul 1, 2040 9,210,337,004
Jul 1, 2045 9,504,209,572
Jul 1, 2050 9,771,822,753
Jul 1, 2060 10,222,598,469
Jul 1, 2070 10,575,846,551
Jul 1, 2080 10,848,708,184
Jul 1, 2090 11,050,055,193
Jul 1, 2100 11,184,367,721

The chart above illustrates how world population has changed throughout history. View the full tabulated data.

At the dawn of agriculture, about 8000 B.C., the population of the world was approximately 5 million. Over the 8,000-year period up to 1 A.D. it grew to 200 million (some estimate 300 million or even 600, suggesting how imprecise population estimates of early historical periods can be), with a growth rate of under 0.05% per year.

A tremendous change occurred with the industrial revolution: whereas it had taken all of human history until around 1800 for world population to reach one billion, the second billion was achieved in only 130 years (1930), the third billion in 30 years (1960), the fourth billion in 15 years (1974), and the fifth billion in only 13 years (1987).

  • During the 20th century alone, the population in the world has grown from 1.65 billion to 6 billion.
  • In 1970, there were roughly half as many people in the world as there are now.
  • Because of declining growth rates, it will now take over 200 years to double again.

Wonder how big was the world's population when you were born?
Check out this simple wizard or this more elaborated one to find out.


Sources:
"It is difficult to write a paradiso when all the superficial indications are that you ought to write an apocalypse." -Ezra Pound

 

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