Patterns of energy use (AQA GCSE Physics): Revision Notes
Patterns of energy use
Energy use patterns around the world have changed dramatically over time. Understanding these changes helps us see why we face energy challenges today.
What causes energy use patterns to change?
Three main factors have changed how humans use energy over the past few centuries:
Population growth - The world's population has grown massively. In just 200 years, we've gone from 1 billion people to over 7 billion people. More people means more energy is needed for homes, transport, and industry.
Technology development - New inventions need energy to work. Cars, trains, planes, computers, and mobile phones all require energy. As technology has advanced, our energy needs have grown too.
Electrical energy demand - Power stations generate electricity for our homes and businesses. As more people want electricity, more fuel is needed to run these power stations.
These three factors work together and reinforce each other. For example, technology development enables population growth through better healthcare and food production, while a larger population creates demand for more technology.
How world population has grown
Population growth has been slow for most of human history, but it has sped up dramatically since 1800. The growth curve looks almost flat until 1800, then shoots upward rapidly. This rapid increase means many more people need energy for daily life.
The population explosion since 1800 represents one of the most significant changes in human history. This exponential growth pattern means that most humans who have ever lived are alive today, creating unprecedented energy demands.
Trends in world energy use
Before 1900 - Wood (biomass) was the main energy source. People burned wood for heating, cooking, and early industries. This use of wood has stayed roughly the same over time.
After 1900 - Fossil fuels became dominant. Coal, oil, and natural gas started being used much more heavily. These fuels powered the Industrial Revolution and modern society.
Recent decades - Nuclear power and hydroelectric power have increased. These newer energy sources help meet growing demand, but fossil fuels still provide most of our energy.
Energy Transition Timeline:
- 1800s: Wood provides 90% of world's energy
- 1900: Coal becomes dominant, wood drops to 50%
- 1950: Oil and natural gas join coal as major sources
- Today: Fossil fuels provide about 80% of global energy, with renewables and nuclear making up the remainder
Energy use vs population growth
Here's an important pattern: energy use has grown much faster than population. This means the average person uses more energy today than people did in the past.
As societies develop, they use more technology that needs energy. People drive cars, use electricity, and buy manufactured goods - all of which require energy to produce and use.
Critical Pattern to Understand:
While global population has increased about 7 times since 1800, global energy use has increased more than 20 times. This shows that rising living standards and technology adoption are major drivers of energy demand beyond just population growth.
Future energy challenges
We face serious problems with our current energy use patterns:
Limited supplies - Non-renewable energy sources like fossil fuels will eventually run out. They took millions of years to form, so once we use them up, they're gone forever.
Environmental impact - Burning more fossil fuels releases more carbon dioxide into the atmosphere. This leads to global warming, which causes severe weather, flooding, and threats to food supplies.
Growing demand - As the world population continues to grow and more countries develop technology, energy demand will keep increasing.
These challenges are interconnected. Environmental concerns are driving the search for alternatives to fossil fuels, while growing demand makes the transition to sustainable energy sources more urgent and complex.
Key Points to Remember:
- Three factors drive energy use changes: population growth, technology development, and electrical energy demand
- Energy use has grown faster than population - meaning each person uses more energy than before
- Wood stayed constant, fossil fuels dominated after 1900, and nuclear/hydroelectric power increased recently
- Non-renewable resources are finite - they will run out eventually
- Increased fossil fuel use causes environmental problems like global warming and extreme weather