### Present Remotely

Send the link below via email or IM

• Invited audience members will follow you as you navigate and present
• People invited to a presentation do not need a Prezi account
• This link expires 10 minutes after you close the presentation

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

# Population

No description
by

## Jason Linn

on 11 April 2014

Report abuse

#### Transcript of Population

Can't stop; Won't stop:
Population & The Environment
An Exploding World
The king said, “no money, no gold.  Just…”
1 grain of wheat on the first square

2 on second
4 on third (etc.)
…for the 64 squares on the board.
How many grains were on the last square?
Legend:  A king offered reward to a chess inventor
Discussions on Population in history
Exponential Growth
Carrying Capacity
Population Growth factors
Outline
Fertile Crescent
Indus Valley Civilization
Roman Empire
Easter Island

Why did they collapse?
Question: Has the human population ever experienced a crash or collapse?
The maximum number of individuals in a species that an environment can sustain indefinitely.
Carrying Capacity
18.5 QUINTILLION grains!!
Tragedy of the Commons
Paul Ehrlich (1932- )
Measurable growth takes two forms: arithmetic and geometric (exponential)

Arithmetic (Linear) operates by the principle of simple addition 2 +2 +2 +2
1,2,3,4,5,6,7

Geometric (Exponential) doubles over time
2 * 2 * 2 * 2
1,2,4,8,16,32,64
Population Growth
Garrett Hardin (1915-2003)
Thomas Malthus (1766-1834)
Lily Anne Y. Welty
Environmental Studies 1
Human Population
August 15, 2012
Ingenuity= Ultimate Resource
Julian Simon (1915-1998)
=
Impact = Population x Affluence (Consumption) x Technology
EXPANSION OF THE HUMAN POPULATION
1998
An Exploding World
Expansion of the Human Population 1998
But ecologist have never found a complex species whose population follows this idealized growth curve. Instead . . .
Yeast and bacteria populations grow like this.
Population
Time
But . . .
Based on averages
Population effect calculated as if proportionate (i.e. big and small consumers treated statistically the same)
Difficult to measure technology and effects
Criticisms of I=PAT
Carrying capacity
Then slows and has a “soft landing.”
Starts out exponential.
Population
Time
Nothing grows uncon-strained forever:
Predators
Disease
Food limits
Resource limits
Constrained Growth
Billion people
You are here!
6.6 billion 2007
5.0 billion 1987
1.7 billion 1910
1 billion 1800
Rome 250 million
Agriculture
10 million
Human Population Through Time
Time
Collapse
Overshoot
Exponential
Or even this.
Stabilize
Oscillate
Overshoot
Time
Populations more typically follow a curve like this:
Overshoot!
Growth rate peaked in 1968 with a doubling time of 35 years.
Average doubling = 50 years
Average doubling = 900 years
Billion people
6.6 billion 2007
1.7 billion 1910
1 billion 1800
Faster than Exponential
Year
1950
2050
2040
2030
2020
2010
2000
1990
1980
1970
1960
0
Population in more-developed countries
1
2
World population (in billions)
Population in less-developed countries
3
4
5
6
7
8
9
10
Fig. 6-3, p. 127
Where Population Growth Occurred
Exponential growth is characterized by:
A constant growth rate.
A constant doubling time.
8
4
2
1
An unconstrained population grows exponentially.
Exponential Growth
A. Infant mortality

Germ theory (1870s)
Vaccination (1796)
Antibiotics
germs = predator; humans = prey

Solutions
Children as part of the labor force

Factors that affect birth rates and fertility

Women: rights, edu,employment

Future
9.2 billion in 2050 according to the 2006 U.N. revision.

U.N. projection = soft landing

1. No other complex species is known to do this.
2. Yeast & bacteria grow like this

Soft Landing?

sanitation
Child labor
education
Is population

Indiv & Society’s Knowledge

Julian Simon
Paul
Ehrlich
Can't stop; won't stop
Population

I = PAT
Malthus (1798)
Mechanical
reaper
Mechanized farming
Women: edu & employment
Or even this.

Populations more typically follow a curve like this
:

Overshoot!

Overshoot & collapse
Human Population Values

The Rapture
babies born year X
Deforestation