LIMIT

S TO G

ROWTH

OVERSHOOT AND C

OLLAPS

E

3 CONDITIONS NECESSARY FOR OVERSHOOT AND COLLAPSE

1. A reinforcing growth loop

2. An erodible limit (carrying capacity)

3. Incorrect or delayed information about that limit

Two Types of Delayed Information about a limit

1. Material

Example: The time from when carbon pollution is created on Earth to when it is completely absorbed in the atmosphere—about 20 years

2. Informational

Example: The time from when data about the melting of the ice caps is generated to when that information reaches the public—about 2 years

THE PREMISE

What if we looked at the 5 characteristics of our world

and simulate over time how they interact with one another:

1.Population2.Cultivated land3.Industrial Capital4.Pollution5.Nonrenewable Natural Resources

What would happen?

MAJOR INTERCONNECTIONS IN MODEL

EXPLANATION

• As population increases, more money is diverted to resource constraints.

• So less capital is available for industrial growth, food, health services, and consumption of goods.

• Wars for territorial ownership of depleting natural resources are costly, further depleting capital and draining social services

• When these decline, population growth overshoots the earth’s carrying capacity and decreases.

REASONS FOR EVENTUAL ACCEPTANCE OF THE MODEL

AND ITS FINDINGS• Accurate representation of historical behavior

• Data used in the model was peer reviewed for accuracy

• Simple, understandable equations thoroughly documented

• The 3 books describing the model were written in nontechnical language, accessible by the general public, and published around the world.

• Reputation of the sponsoring institution—MIT

• Challenges to the underlying assumptions of the model never changed its fundamental behaviors

HISTORY OF PUBLICATIONS

1972—Limits to Growth1992—Beyond the Limits2002—The 30 Year UpdateThese books don’t predict the future. Rather,

they provide alternative scenarios about the future.

Criticism of the model:1973 Models of doom—A Critique of Limits to

Growth

TEN SIMULATIONS OF THE MODELEach of the ten simulations scenarios addresses a concern of the

previous simulation:

1. Standard run—business as usual

2. Increasing natural resource base

3. Pollution control technologies

4. Enhancing agricultural yields

5. Land erosion protection

6. Resource efficiency technologies

7. Stabilized population

8. Stabilized industrial output per capita

9. Technologies to reduce pollution, conserve resources, and increase land yield

10. Same policies introduced 20 years earlier—true sustainability

INCREASING NONRENEWABLE RESOURCE BASE—Scenario 2

Parallels of Limit to Growth and Climate Change

What we do now does not have impact for many years to come. This delay causes the overshoot of the earth and the atmosphere’s eroding carry capacity. This results in collapse of the earth’s and the atmosphere’s ability to absorb more toxins.

THE UNATTAINABLE STEADY-STATE SOLUTION—Scenario 10

Author’s quote from “Beyond the Limits”