Ups and downs of Population

7 Ups and downs of Population

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

Outline

Overview

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

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

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.

Formulas

Population is P

N – M + (Em ± 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 = "–"

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.

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.

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

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

Terms

A hectare is 10,000 square meters or

2.471 acres.

Exponential growth [migration] versus natural increase [fertility]

Growth:

"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.

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