7       Ups and downs of Population

 

population changes

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 

 

Prologue

 

“Human population growth has been so prodigious in recent centuries that it has also become a major driver of environmental deterioration, in the extent of pollution, consumption of natural resources, and destruction of habitats needed by other species.”

p. 140

crad

 

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 

Outline

 

  Overview

 

            the elephant in the living room” is the matter of population size

 

Total fertility rate

   

Population dynamics

Population genetics and gene pools:

“Population genetics is concerned with changes through time in the composition of gene pools (all the genetic information possessed by a population), …; population dynamics or demographics … is about changes to the numbers of individuals and in the forces that produce these changes in a given population.” (140)

 

            Population is “an input-output system.” – see formulas { 141

.    Butterfly dynamics–checkerspot butterfly life cycles { 141

.    Human dynamics – 6.859 billion people July ‘10 { 142

.    Family Planning { 144

.   Curbing the population explosion { 146

.   The arithmetic of population growth { 149

.   Population pyramids { 151-52

.   Population momentum { 153

.   Aging populations { 155

 

 

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 

Rise in global population density.
Year number of inhabitants people per square mile
1810 1,000,000,000

17.4

1850 1,171,000,000 20.4
1900 1,608,000,000 27.9
1930 2,000,000,000 34.8
1960 2,972,000,000 51.7
2000 6,080,000,000 105.7
2012 7,000,000,000 121.7

57,500,000 square miles of dry land.

Source: maps of growth-- http://desip.igc.org/populationmaps.html

http://www.vaughns-1-pagers.com/history/world-population-growth.htm

 

 

Population profiles or pyramids of an aging United States.

 

Three patterns inherent in population profiles:

 

youthful & growing | stabilizing slowly | aging & declining

 

The width of the lines is proportional to the number of people in that age group, called cohorts; males on the left, women on the right.

 

 

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 

 

Formulas

 

 

Population is P

 

N – M + (Em Ī  Im) = P

 

The natality is N for fertility or birth rates. M is mortality or death rates.

 

          (N) Fertility minus (M) mortally (plus or minus migration) equals population

 

migration

• immigration is Im the measure of people coming to a designated area; into = "+"

• emigration is the inverse or Em and refers to the number of people leaving a designated area; out of = "–"

 

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 

Impact        is represented by the letter       I.

 

Impact formula.

I = P * A * T

explained

       Impact is equal to Population times Affluence times Technical capabilities that affect carrying capacity.

 

 


The several factors in estimating the scale of human impacts.

2012 estimates Africa Asia Europe North America
I impact 2.8 29.2 20.1 16.1
=  
P population 1072 4260 740 349
* in millions
A affluence or per capita income $2,630 $6,860 $27,080 $46,400
* GNP (US, 2010 equivalent)
T technology or carbon footprint / electricity use 4,532 2,631 5,692 12,914
    S. Africa China UK USA
  People per square kilometer        
D density 35 134 32 16

Note: electricity use or, Electric power consumption (kWh per capita)
Electric power consumption measures the production of power plants and combined heat and power plants less transmission, distribution, and transformation losses and own use by heat and power plants.

Source: World Bank.

 

Source: World Population Data Sheet.

 

There is a problem, for example, with African & Asian electricity figures:

 

African figures:

 

Nations Congo Kenya Egypt Botswana
KW hours / capita 151 149 1440 1533

 

Asian figures:

 

Nations China India Indonesia Japan
KW hours / capita 2631 171 590 7819
 

 

Because the averages for Asia and Africa mask these extreme regional differences.

 

 

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 

Case studies in dynamics

 

France

 

French population change 1901-2001

The width of the lines reflects the number of people in that age group or cohort.

 

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 

 

The algorithm for how long it takes for a known rate of increase (a percent per year) to double is called:

 

"The rule of 70"

                                            % / 70 = TD

                                    percent ÷ 70 equals doubling time [TD]

 

 

 

Summary

“ . . . the problems that continued rapid global population growth is now bringing to the planet, that, in the view of the vast majority of knowledgeable scientists is already overpopulated.”

p. 157

 

US Bureau of the Census on line

The Encyclopedia of Earth

 

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time 

 

line

Population dynamics is the key to understanding the human reality of birth, death and migration as it characterizes any region.

 

Understanding aggregate behavior of large numbers allows us to put cases of individuals and regional impacts into a more understandable perspective.

 

impacts

 

For example, the aging of the populations in Japan and Russia will affect each nation's ability to consume resources despite the differences in the compact area of the island of Japan and the huge area of Siberia that Russians and other nationalities may use.

 

Twenty years of population growth may indicate the need to compare more data for nations with respect to density, urbanization per capita income and commercial range.

 

Compared to the United States (USA) with 265.2 million people and .75 hectares of cropland per person available in the 1990s, consider these five nations:

1990

 

World population was 5,771 million people.

 

Nations Japan Russia France Thailand India measure
population 125.8 147.7 58.4 60.7 949.6 millions
per capita cropland .04 .79 .34 .41 .20 hectares

2010

World population was 6,892 million people.

Nations Japan Russia France Thailand India Egypt USA measure
population 127.4 141.9 63 68.1 1188.8 80.4 309.6 millions
density 337 8 114 133 362 80 32 / sq. kilometers

Over time the US population is shifting due to fertility rates and migration, the largest proportion of increase from fertility is now among Latino or Hispanic populations, with those under 18 years of age having increased 38 per cent in a decade (2000-2010) compared to a 9.8 per cent decline in the white population and a 2.3 percent decline in the African-American population of the same age group (under 18).

pyramid

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

Terms

A hectare is 10,000 square meters or

2.471 acres.

next

 

 

Exponential growth [migration] versus natural increase [fertility]

 

Growth:

asymptote

 

"Population growth has been so prodigious in recent centuries that it has also become a major driver of environmental deterioration, in the extent of pollution, consumption of nature's resources, and destruction of habitats needed by other species."

p. 140.

florida

Exponential growth patterns are due to migration, not natural increase or refined fertility rates.

 

line

 

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 

Natural increase is linked with the Golden ratio through the Fibonacci sequence, (C. below) which is given by the difference between these number progressions:

 

Two sequences of increasing numbers -- or rates of progression
alpha Type of increase
1st
2d
3d
4th
5th
6th
7th
8rth
9th
10th
11th
12th
D
deficit (minus)
0
1
2
5
11
24
51
107
222
457
935
1904
C fibonacci
1 
1 
2
3 
5 
8 
13
21 
34 
55 
89 
144 
B exponential >
1 
 2 
4 
8
16
32
64
128
256 
512 
1024 
2048 
A arithmetic sequence 1 2 3 4 5 6 7 8 9 10 11 12

 

 

 

Vocabulary 

 

Demography: fertility, mortality, immigration, emigration, natural increase

Natality,

rule of 70, doubling time,

Fibonacci sequence,

Infant death, contraception,

migration,

Malthusian dilemma.

populate,  

exponential versus arithmetic growth, inverse square law, correlation.

 

Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 

Review Outline

     Overview

            “the elephant in the living room” is the matter of population size

“Population genetics is concerned with changes through time in the composition of gene pools (all the genetic information possessed by a population), …; population dynamics or demographics … is about changes to the numbers of individuals and in the forces that produce these changes in a given population.” (140)

           Population is “an input-output system.” – see formulas { 141

.             Butterfly dynamics–checkerspot butterfly life cycles { 141

.    Human dynamics – 6.859 billion people July ‘10 { 142

.           Family Planning { 144

.        Curbing the population explosion { 146

.              The arithmetic of population growth { 149

.           Population pyramids { 151-52

.   Population momentum { 153

.        Aging populations { 155

Summary


Prologue | Details | Outline | Vocabulary | Data Sheet, 12 | Density | Profiles | Dynamics | Two Formulas | Impact | Doubling time

 
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