Human population growth

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

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)

“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

Vocabulary

Demography: fertility, mortality N>, rule of 70, doubling time, Fibonacci sequence, Infant death, contraception, migration, Malthusian dilemma, exponential versus arithmetic growth, inverse square law, correlation.

Population distribution, graphs

Formulas

Population N – M + (Em ± Im) = P

Fertility minus mortally (plus or minus migration) equals population

Impact I = P * A * T

Impact is equal to Population times Affluence time Technical capacity

Population History

French population change 1901-2001

Doubling time

The rule of 70

% / 70 = TD

percent ÷ 70 equals doubling time [TD]

The percentage of change divided by seventy (or seventy-two) is the time it takes for a quantity to double [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 impacts any region.

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

These are all linked with the Golden ratio through the Fibonacci sequence, which is given by

Four sequences
The differences among arithmetic, fibonacci, & exponential growth patterns.
A	one	two	three	four	five	six	seven	eight	nine	ten	eleven	twelve
F	1	1	2	3	5	8	13	21	34	55	89	144
Ex	1	2	4	8	16	32	64	128	256	512	1024	2048
difference	0	1	2	5	11	24	51

U. S. Population

World Population

Additional material