Rev. Thomas Malthus's Essay on Population (1798):
Exponential population growth will outstrip food production.
Humans will be reduced to subsistence living.
Exponential population growth example:
E. coli doubles every 20 minutes, so…
If you start with only 1 μg of E. coli under your fingernail
in 4 hours: 4 grams
In 8 hours: 16Kg
In 12 hours: 68 metric tons
In 24 hours: enough to cover the entire Earth about 2 miles deep.
(Please wash your hands!)
Time Population
1
10
2
20
3
40
4
80
5
160
6
320
7
640
8
1,280
9
2,560
10
5,120
11
10,240
12
20,480
13
40,960
14
81,920
15
163,840
16
327,680
17
655,360
18
1,310,720
19
2,621,440
20
5,242,880
21
10,485,760
22
20,971,520
23
41,943,040
24
83,886,080
25
167,772,160
26
335,544,320
27
671,088,640
28
1,342,177,280
29
2,684,354,560
30
5,368,709,120
31
10,737,418,240
32
21,474,836,480
33
42,949,672,960
34
85,899,345,920
35
171,798,691,840
36
343,597,383,680
37
687,194,767,360
38 1,374,389,534,720
39 2,748,779,069,440
Population
3,000,000
2,500,000
2,000,000
1,500,000
1,000,000
500,000
-
0
5
10
15
20
35
40
Population
3,000,000,000,000
2,500,000,000,000
2,000,000,000,000
1,500,000,000,000
1,000,000,000,000
500,000,000,000
-
20
25
30
Exponential growth looks the same from any
point in time!
Jonathan Swift’s A Modest Proposal (1729):
"I have been assured by a very knowing American of my
acquaintance in London, that a young healthy child well nursed
is at a year old a most delicious, nourishing, and wholesome
food, whether stewed, roasted, baked, or boiled; and I make
no doubt that it will equally serve in a fricassee or a ragout."
Garrett Hardin (1968) Tragedy of the Commons
Our long-term survival will require progressive elimination of
freedoms--including government restrictions on reproductive
rights--and growing reliance on "mutual coercion."
A grazing common in Scotland
Paul Erlich – choice quotes:
"We must have population control at home, hopefully through a
system of incentives and penalties, but by compulsion if voluntary
methods fail. We must use our political power to push other
countries into programs which combine agricultural development
and population control.“
“In ten years all important animal life in the sea will be extinct.
Large areas of coastline will have to be evacuated because of the
stench of dead fish.“ (1970)
"By the year 2000 the United Kingdom will be simply a small group
of impoverished islands, inhabited by some 70 million hungry
people ... If I were a gambler, I would take even money that
England will not exist in the year 2000.“ (1971)
The real tragedy is that people believe this stuff!
Putting Hardin’s recommendations into practice: China’s one-child policy
The tragedy of a terrible social policy:
•
•
•
•
400 million coerced abortions
30 million missing girls due to sex selection
Fines, corruption & bribery
Shortage of workers vs. retirees will slow economic growth
Little emperor?
Visit your parents
--it’s the law!
US age profile, by year
(2010 Census of Population)
Are natural resources really
getting less scarce?
Simon’s bet vs. Paul Erlich:
Erlich chose a $1,000 “portfolio”
of commodity minerals—copper,
chromium, nickel, tin and
tungsten—to track over 10 years.
If its value increased, Simon
would pay Erlich the increase.
If its value decreased, Erlich
would pay Simon the decrease.
Its value decreased 57%; Erlich
paid Simon $576.07.
Julian Simon
1932-1998
POPULATION GROWTH RATE vs GDP/Capita
5
4.5
POPGRWTHRATE = -0.431ln(x) + 5.0678
R² = 0.2318
4
3.5
3
2.5
2
1.5
1
0.5
0
$100
$1,000
$10,000
$100,000
50
BIRTHRATE & DEATHRATE vs GDP/Capita
45
40
BIRTHRATE = -6.225ln(x) + 76.585
R² = 0.6428
35
DEATHRATE = -0.562ln(x) + 13.092
R² = 0.0541
30
BIRTHRATE
DEATHRATE
25
Log. (BIRTHRATE)
Log. (DEATHRATE)
20
15
10
5
0
$100
$1,000
$10,000
$100,000
100
LIFE EXPECTANCY vs GDP/Capita
90
80
70
60
50
LIFE EXPECTANCY = 5.6698ln(x) + 19.747
R² = 0.628
40
30
$100
$1,000
$10,000
$100,000
So if economic growth is the solution to the population problem,
what drives economic growth?
GDP per Capita vs. Gini Coefficient (Income Inequality)
$100,000
GDPPCAP = 50735e-0.045x
R² = 0.1262
$10,000
$1,000
$100
20
25
30
35
40
45
50
55
60
65
70
Components of the commons problem:
1. Very slow reproduction or recovery
2. Hard to privatize
3. Inelastic demand: scarcity increases price, but
demand is not very responsive to price
4. Institutional failures: govt. corruption, non-enforceability of
conservation agreements
“Common Property” vs. “Open Access” (non-excludable)
Resource markets anticipate future prices.
But the naïve static reserve index ignores this:
Reserves ÷ Annual Consumption = Years until we run out!!
Logical fallacies:
1. rising price signals scarcity, moderates consumption
2. “reserves” are not static!
“Peak Oil” predictions…going wrong!
Do not confuse “Reserves” with the physical resource base!
As resources get scarcer, their prices increase.
Rising prices moderate scarcity by motivating
--conservation
--efficiencies in resource use
--discovery and development of new reserves
--substitution to alternative resources
US Petroleum inventory
Long Beach, CA, oil field (1920)
Flaring natural gas from Iraqi oilfield
What happens when we run out?
Extraction of crude from Canadian tar sands
PBF refinery, Delaware City, DE
Delaware’s
Coastal Zone Act
“grandfathers”
the PBF refinery,
but bars
expansion
outside its
original footprint
and bars transshipments of
crude (to PBF’s
other refinery in
Paulsboro, NJ).
ALTERNATIVE ENERGY SOURCES
Ethanol: E10 mandate diverts 40% of US corn crop from food to fuel:
51 cents/gallon federal subsidy to U.S. producers.
Hoover Dam hydropower
Geo-thermal
Nissan Leaf all-electric, approx. 70 miles/charge @ 3½ cents/mile