human population change chapter 8b raven and berg 1/9/2016o'connell: human population 8b1

Human population change

Chapter 8bRaven and berg

1/9/2016 O'Connell: Human Population 8b 1

Finite space

1/9/2016 O'Connell: Human Population 8b

[Earth,] A tiny raft in the enormous, empty night.- Archibald MacLeish (1970)

2

The Human Population

Current world population as of Jan. 9, 2016 is:7,297,700,000 (per Population Connection)

Demography: science of human population structure and growth.

http://www.prb.org/pdf15/2015-world-population-data-sheet_eng.pdf


Data Sites• http://www.prb.org • http://www.prb.org/pdf15/2015-world-population-

data-sheet_eng.pdf • http://www.populationconnection.org/ • http://www.census.gov • https://www.cia.gov/library/publications/the-

world-factbook/ • http://data.worldbank.org/indicator/SP.POP.GROW


Where the growth comes from

Current Population NumbersRapid growth primarily due to drop in death rates


Thomas Malthus• British economist (1766-

1834)• Populations were increasing

faster than food production• Could not be sustained • Didn’t foresee the advent

(arrival) of the Industrial Revolution


Population growth

• 1 billion – about the year 1800• 2 billion – 1930 • 3 billion – 1960 • 4 billion – 1975• 5 billion – 1987• 6 billion – 1999


Ninth

Eighth

Seventh

Sixth

Fifth

Fourth

Third

Second

First Billion

Number of years to add each billion (year)All of Human History (1800)

130 years (1930)

30 years (1960)

15 years (1975)

12 years (1987)

12 years (1999)

12 years (2011}

14 years (2027)

21 years (2048)

Sources: First and second billion: Population Reference Bureau. Third through ninth billion: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

World Population Growth, in Billions

Agricultural Revolution: 10,000 BCIndustrial Revolution: 1800 ADBaby Boom: 1946 - 1964

How Much is a Billion?How Much is a Billion?• 1,000 seconds = 16.7 minutes• 1 million-s = 16,677 min = 11.6 days• 1 billion-s = 11,574 days = 31.7 years_________________________________________• 1,000 pennies = ~ 88 ounces = 5.5 pounds• 1 million pennies = 5,500 pounds (~1-Suburban)• 1 billion pennies = 2,750 tons (~2 Space Shuttles)


A.D.2000

A.D.1000

A.D.1

1000B.C.

2000B.C.

3000B.C.

4000B.C.

5000B.C.

6000B.C.

7000B.C.

1+ million years

8

7

6

5

2

1

4

3

OldStoneAge New Stone Age

BronzeAge

IronAge

MiddleAges

ModernAge

Black Death —The Plague

9

10

11

12

A.D.3000

A.D.4000

A.D.5000

18001900

1950

1975

2000

2100

FutureBillions

Source: Population Reference Bureau; and United Nations, World Population Projections to 2100 (1998).

World Population Growth Through History

Total Fertility Rate

• The average number of children a woman can have in her lifetime

• 2.1 replacement rate


Top 10 Most Populous countries

1. China 1,367,485,388 6. Pakistan 199,085,847

2. India 1,251,695,584 7. Nigeria 181,562,056

3. United States 321,368,864 8. Bangladesh 168,957,745

4. Indonesia 255,993,674 9. Russia 142,423,773

5. Brazil 204,259,812 10. Japan 126,919,659


density of Countries


Decreasing growth rate

• From a peak of 2.2% (1964 – end of the Baby Boom) to 1.13% per year in 2016

• Mexico example– r = 26/1000 – 5/1000 = 0.026 – 0.005 = 0.021/100 =

2.1% per year• Absolute numbers are increasing due to sheer

volume of people of reproductive age – Baby Boom echo


Projected growth

• Population rate was 1.13% per year in 2015• Population will top out at 9 billion in the year

2050 • Zero population growth

– When the birth rate equals the death rate


Zero population growth

• Projecting Future Population Numbers– When will zero population

growth occur?


World Population Growth rate and Absolute Growth


Doubling time

• The amount of time it would take for a population to double in size (td )

• td = 70%/r

– Called the Rule of 70


Doubling time example• How many years would it take for the population

of Guatemala to double in size at the 2007 growth rate?– Needed information:

• Current population: 13.4 million (13,400,000)• Birth rate (b): 34 (per 1000 people)• Death rate (d): 6 (per 1000 people)• Growth rate (r): r = b – d (natural increase)• td = 70%/r


Doubling time example Calculations:

Growth rate (r) = 34/1000 – 6/1000 or 34 - 6

1000= 0.034 – 0.006= 0.028 (x 100 = 2.8%)

• td = 70%/r = 0.7/0.028 = 25 years

– At the current growth rate of 2.8% it will take the population of Guatemala 25 years to double in size.


Developed vs. Developing countries(table 8.2)

2004 Population Data United States (Highly

Developed)

Brazil(Moderately Dev.)

Ethiopia(Less Developed)

Fertility rate 2.0 2.2 5.9

Projected population change 2004-2050*

+43% +24% +139%

Infant mortality rate 6.7 per 1000 33 per 1000 105 per 1000

Life expectancy at birth 77 years 71 years 46 years

Per capita GNI PPP** $36,110 $7,450 $780

Women using modern contraception

72% 70% 6%


*Includes fertility, mortality, and migration estimates**GNI PPP = gross national income in purchasing power parity (at 2002 US dollars) 21

08_15.JPG

Demographic Stages Pre-industrial Stage

Birth and death rates high, modest population growth

Transitional Stage Lowered death rate, rapid population growth

Industrial Stage Birth rate decline, population growth slow

Post Industrial Stage Low birth and death rates, population growth very

slow1/9/2016 O'Connell: Human Population 8b 23

Demographic Transition Comparisons


Age structure pyramids


•Each row covers 5 years (e.g. 10 year olds – 14 year olds)•Males are on one side and females on the other•Percent or numbers of population on the bottom •3 basic types of pyramids

25

Age Structure Diagrams


Demographic example

• Nigeria– What affect will this

have on Nigeria’s future?


Demographic example

• United States– What affect will this have

on the United States’ future?


Tracking the baby-boom generation in the United StatesTracking the baby-boom generation in the United States


Demographic example

• Germany– What affect will this have on

Germany’s future?


Age structure

pyramid of Germany


Population Under Age 1530% of the human population is under age 15


Aging population

• Strain on retirement programs (e.g. pensions)• Health problems• Less workforce


•A country is A country is OVERPOPULATEDOVERPOPULATED if: if:–If the population cannot be sustainably supportedIf the population cannot be sustainably supported

•People overpopulationPeople overpopulation– environment is harmed because of too many environment is harmed because of too many peoplepeople

•Consumption overpopulationConsumption overpopulation– environment is harmed from too much environment is harmed from too much consumptionconsumption

Numbers vs ConsumptionNumbers vs Consumption

I. Population and the environmentA. IPAT model- measures humans’ total impact (I) on the environment

I = P x A x TP = population

A = affluence T = technology

1. Increase in any factor increases the environmental impacts.

2. Impacts to env. are generally pollution and resource

consumption.

Environmental Impact

05/03/23 36Fig. 1-11 p. 13

human population change chapter 8b raven and berg 1/9/2016o'connell: human population 8b1

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