Patterns of energy use (AQA GCSE Physics Combined Science): Revision Notes
Patterns of energy use
Why energy use patterns have changed
Energy use around the world has changed a lot over time. There are three main reasons for this transformation:
Population growth - In the last 200 years, the world's population has grown from 1 billion people to 7 billion people. More people means we need more energy for everything.
Technology development - We now have cars, trains, planes and many other machines that didn't exist before. All these devices need energy to work.
Electrical energy - Power stations need fuel to make electricity. As we use more electrical devices, we need more fuel to generate power.
These three factors work together - as population grows, more technology is developed to meet people's needs, which in turn requires more electrical energy to power our modern lifestyle.
Population growth and energy use
The world's population has grown very quickly, especially since 1900. The growth follows a curved pattern that gets steeper over time. This is called exponential growth.
Energy use has grown in a similar way to population. However, energy use has actually grown faster than population. This means the average person now uses more energy than people did in the past.
Understanding Exponential Growth
Exponential growth means the rate of increase gets faster over time. Instead of growing by the same amount each year (linear growth), the population and energy use grow by increasingly larger amounts each decade.
How energy sources have changed over time
The transition in our primary energy sources reveals a clear pattern of technological and industrial development:
Before 1900 - Most energy came from biomass, especially wood. People burnt wood for heating, cooking and some industrial processes. This stayed fairly constant for many years.
After 1900 - Fossil fuels became much more important. Coal, oil and natural gas use increased rapidly. These became the main energy sources for most countries.
Recent years - We've started using more nuclear power and hydroelectric power. However, fossil fuels still provide most of the world's energy.
The graph shows that our total energy use has increased dramatically, especially since 1950. Most of this increase has come from using more fossil fuels.
Future energy concerns
We cannot keep using non-renewable energy sources forever. Coal, oil and natural gas are finite resources - they will eventually run out and cannot be replaced.
Using more fossil fuels creates more carbon dioxide in the atmosphere. This leads to serious environmental consequences:
- Global warming
- More extreme weather
- Flooding in some areas
- Problems with food production
Critical Environmental Impact
These are serious issues that affect everyone on the planet. The continued reliance on fossil fuels is not sustainable and poses significant risks to our climate, ecosystems, and future generations. Understanding these consequences is essential for making informed decisions about energy use.
Key Points to Remember:
- Three factors drive changing energy use: growing population, new technology, and increased electricity demand
- Population has grown from 1 billion to 7 billion in just 200 years
- Energy use has grown faster than population - each person now uses more energy
- Fossil fuels replaced wood as the main energy source after 1900
- Non-renewable resources will run out and cause climate problems if we keep using them