Economics and Limits to Growth:
What’s Sustainable?
Dennis Meadows
at
The Population Institute
Washington, DC
October 6, 2009
1
The Reference Scenario
Original
Report
Today
Industrial Output
Population
Pollution
Resources
Food
2
Main Insights from the Scenario
• In 1972 we expected another 40-80 years of growth.
• All our scenarios showed growth ending in the period
2010-2050.
• The preponderant mode was overshoot and decline, not
gradual slowing within a limit.
• Changes in technology may delay the end of growth by a
few years, but they do not avoid it, and they do not avoid
the decline.
• Social changes are essential for the attractive futures.
• What are today considered to be problems are actually
symptoms. The real problem is physical growth in
material and energy flows pressing against the limits of a
finite planet.
3
Main Points of My Speech
• Growth has continued until we are now past sustainable
levels.
• The global society will change more over the next 20
years than in the past 100. Design policies for what is
coming, not what has been.
• The main forces for change will be climate change and
resource scarcity - especially fossil fuels and water.
• The end of growth does not result from total depletion,
but from rising capital costs.
• The most important scarcity is the absence of a longerterm perspective.
4
World Population
5
Industrial Production
6
Index of World Metals Use
7
“Sind die Menschen noch zu retten?” Die Zeit, 16.11.06
If current trends of overfishing and pollution continue, ..
all seafood faces collapse by 2048.
By the middle of the century … no fewer than 7 billion
people in 60 countries may be faced with water scarcity.
Human beings and the natural world are on a collision
course. .. Fundamental changes are urgent….
- more than 1,600 scientists, including 102 Nobel laureates, from 70 countries
(Ignoring climate change) “could create risks of major
Disruption to economic and social activity… on a scale
Similar to those associated with the great wars.”
Stern Review October 2006
8
One Indicator of Overshoot
9
Other Indicators of Overshoot
10
The Sequence of Objections
• 1970s: There are no limits.
• 1980s: There are limits, but they are distant in
time.
• 1990s: The limits are near, but they are
irrelevant, since they will be dealt with by the
market.
• 2000s: The market is not adequate, but new
technologies will let us evade the limits without
requiring that we stop growth.
11
Capital Cost of Discovery
C
o
s
t
0
Fraction of Resource Remaining
1
12
Capital Cost of Abatement
C
o
s
t
0
Fraction of Sink Remaining
1
13
Energy Return on Investment
14
15
The Time of Greatest Stress
• Most people assume that the major global
difficulties would occur after the end to growth.
• This is not correct.
• The globe’s population would experience the most
stress prior to the peak, as pressures mount high
enough to neutralize the enormous political,
demographic, and economic forces that now
sustain growth.
• We are in the early phases of that period now.
16
CO2 Concentration
17
Four Factors Determine the
Amount of CO2 Emissions
CO2
Emissions
Number
Units of
Energy
of x Capital x Required per x
People Per Person Capital Unit
Efficiency
Demography
Cultural
Norms
Fraction of
Energy from
Fossil Fuels
Solar Energy
Technology
© Dennis Meadows; 2007
18
A Problem
Better ------->
Time Horizon
Desired
Actual
Now
Next Evaluation
Future
19
Easy Problems
Better ------->
Action #1
Desired
Actual
Action #2
Now
Next Evaluation
Future
20
Difficult Problems
Better ------->
Action #1
Action #2
Desired
Actual
Now
Next Evaluation
Future
21
Relying on Present
Net Value to Choose Assumes:
• All consequences of an action are known
• All consequences can be expressed in monetary units; they are
commensurate
• We are the ones entitled to pick the interest rate
• Maximizing financial benefits is the goal of society
• Current mistakes can be corrected by paying some cost in the
future
Every single one of these assumptions is false for the issue of
climate change!!
22
Scarica

Dennis Meadows