Overview
This lecture summarizes the findings of the 1972 MIT "Limits to Growth" study and its subsequent analyses, focusing on the predicted global societal collapse and the key factors influencing such an outcome.
Historical Context & Major Civilizations
- Advanced human civilizations have existed for roughly 10,000 years, with empires rising and falling over time.
- Civilizational collapse is usually due to a mix of political, social, environmental, and economic factors.
- Some collapses were sudden (e.g., Pompeii), others gradual (e.g., Rome).
Modern Civilization & Wealth
- Modern society is wealthier and more advanced than any previous civilizations.
- Today's average person enjoys luxuries and safety far beyond historical elites.
- Global peace and prosperity largely stem from technology, education, and international cooperation.
The Limits to Growth Study (MIT, 1972)
- "Limits to Growth" aimed to model if current resource use was sustainable.
- It used early computer models (World 3) simulating complex global systems.
- Five key variables tracked: population, industrial output, food production, available resources, and pollution.
Modeling & Feedback Loops
- Feedback loops in the model show how interconnected variables can create cycles (e.g., declining birth rates and aging populations).
- The model tested various assumptions: constant innovation, technological breakthroughs, and plateaus.
Key Scenarios from the Study
- Comprehensive Technology Scenario: Constant innovation keeps up with needs; problems like pollution are solved through new tech.
- Stabilized World Scenario: Moderate innovation plus heavy investment in renewables/recycling; voluntary reduction in industrial output prevents shortages.
- Business as Usual 2 Scenario: No major changes; pollution increases, resources dwindle, causing population and economic collapse—this scenario most closely matches real-world data as of 2021.
Criticisms and Current Developments
- Critics argue the study underestimates human innovation's ability to avert disaster.
- Data as of 2021 matches the pessimistic scenario, though improvements in renewables are hopeful signs.
- The future depends on societal choices, innovation, and adapting to resource limitations.
Key Terms & Definitions
- Feedback Loop — A process where outputs of a system are fed back as inputs, amplifying changes.
- System Dynamics — A modeling approach to simulate complex systems and their interactions.
- Business as Usual Scenario — A projection assuming current trends continue without major intervention.
- Systematic Model — A computer-based simulation representing how multiple variables interact over time.
Action Items / Next Steps
- Read the original "Limits to Growth" (1972) and the 2021 follow-up study by Gaya Herrington.
- Consider societal impacts of innovation, resource use, and personal choices regarding sustainability.