Lecture Notes: Energy and the Future

Review of Energy Concepts

• Energy and Work: Energy allows us to perform work; measured in joules (J).
• Power: Energy per unit time, measured in watts.
• Formula: Work = Force x Distance (measured in newton meters or joules).

Population Growth and Energy Demand

• Exponential population growth:
  • Took 200,000 years to reach 1 billion people.
  • From 0 AD to 1850, reached 1 billion.
  • From 1850 to present, increased by 7 billion.
• Rising energy demands with population growth.
• US energy consumption disproportionately high relative to its population.

Sustainability Concerns

• High energy consumption may not be sustainable.
• Potential energy crisis due to over-reliance on energy.

Types of Energy

• Non-renewable Energy: Fossil fuels (coal, oil, natural gas) and nuclear power.
• Renewable Energy: To be discussed in a subsequent lecture.

Origin of Energy

• Most energy originates from the sun, except geothermal and nuclear.
• Fossil fuels formed from ancient organic materials.
• Energy from burning fossil fuels produces CO2.

Fossil Fuels

1. Coal

   • Major source of electricity.
   • US uses about 1 billion tons/year.
   • Coal reserves may deplete in ~120 years.
   • Environmental impact: significant CO2 emissions.

2. Oil

   • Used for transportation (gasoline).
   • Limited supply; potential for depletion in ~40 years.
   • High environmental impact, pollution.
   • Energy security concerns due to dependency.

3. Natural Gas

   • Extracted similarly to oil; often using water to push out gas.
   • Burns cleaner than oil/coal but still contributes to pollution.

Greenhouse Effect and Pollution

• Greenhouse Gases: CO2, methane, nitrogen forms, water vapor.
• CO2 traps solar radiation, causing warming.
• Keeling Curve shows increasing CO2 levels.
• Debate over anthropogenic vs natural causes of CO2 increase.

Nuclear Energy

• Pros:
  • Generates electricity with no CO2 emissions during operation.
  • Efficient energy production through nuclear fission.
• Cons:
  • High cost for building and decommissioning plants.
  • Produces radioactive waste.
  • Risks of accidents (e.g., Fukushima, Chernobyl).

Conclusion

• Focused on non-renewable energy sources and their impacts.
• Discussed possible future energy crises due to non-renewable energy.
• Upcoming discussion on renewable energy and sustainable living.