Nature’s Treasures · Lesson 6 of 8
Fossil Fuels and Cleaner Choices
“Connect familiar fuels to their ancient origins, limited supply and effects on air.”
• Survey vehicle fuels and identify common uses of petroleum, coal and natural gas. • Explain in sequence how fossil fuels formed over millions of years. • Explain why fossil fuels are limited and how burning them pollutes air. • Compare practical ways to reduce dependence on them.
What powers a vehicle?
At a filling station, different vehicles may take different fuels. Make a safe survey from observation or by asking adults: record vehicle type and fuel used, without approaching moving traffic. Petrol and diesel are common. A table makes it possible to compare the fuels you actually find rather than assuming every vehicle runs on the same one.
| Vehicle type observed | Fuel reported or identified | How you know |
|---|---|---|
| Two-wheeler | Record a real observation, often petrol | Ask an adult or check reliable vehicle information |
| Car | Record petrol, diesel, CNG or electricity as appropriate | Do not guess from appearance alone |
| Bus or other vehicle | Record actual fuel | Compare survey results |
Where the fuels came from
Petrol, diesel and kerosene are obtained from petroleum. Petroleum, natural gas and coal are called fossil fuels. Their origin lies in remains of plants and tiny organisms that were buried deep in Earth and changed over millions of years. The process is extremely slow compared with our daily use. The diagram shows the sequence, not a recipe that could be completed quickly.
Coal, petroleum and natural gas, fuels formed from long-buried remains of living organisms over millions of years.
Problem
A student lists petrol, diesel, kerosene, coal and natural gas. Which are obtained from petroleum, and which are the main fossil-fuel groups?
- 1.Petrol, diesel and kerosene are products obtained from petroleum.
- 2.Petroleum itself, coal and natural gas are the main fossil-fuel groups named in the chapter.
- 3.Do not count petrol and petroleum as wholly unrelated natural origins: the former comes from the latter.
Different jobs, different forms
Petrol and diesel often power vehicles. Natural gas can be used for cooking and electricity generation. Compressed Natural Gas, or CNG, is a form used in vehicles and is described as cleaner than petrol or diesel. Liquefied Petroleum Gas, or LPG, and natural gas have gradually replaced some earlier household cooking fuels such as wood, dung cakes and coal. Coal is mainly used to produce electricity. These examples show why fuels matter to travel, homes and power supplies.
| Fuel or form | Use highlighted in the chapter |
|---|---|
| Petrol and diesel | Vehicle fuel |
| Kerosene | Product obtained from petroleum |
| Natural gas and LPG | Cooking; natural gas also generates electricity |
| CNG | Vehicle fuel; cleaner than petrol or diesel |
| Coal | Mainly electricity production |
CNG is described as cleaner than petrol or diesel, but it is still a fossil fuel. A vehicle using electricity has no smoke coming from its tailpipe, yet the source of its electricity also matters when considering pollution overall.
Use limited fuels wisely
Fossil fuels are available in limited quantities. We use them far faster than they can form, so continued wasteful use will exhaust supplies. Burning them releases smoke and carbon dioxide and contributes to air pollution. Extensive use in vehicles and homes can make city air unpleasant and unhealthy. Walking or cycling for short trips and using public transport can reduce fuel use; solar and wind energy are other energy sources explored in this chapter.
Problem
A family member plans to drive a short distance alone. Suggest a way to use less fossil fuel and explain it.
- 1.Check whether the trip is safe and practical on foot or by bicycle.
- 2.If so, make the journey without burning petrol or diesel in that vehicle.
- 3.For longer trips, shared public transport may reduce the number of separate vehicles on the road. The choice depends on distance and circumstances.
To investigate local air quality, ask community members what sources of smoke they notice, and separate observed facts from assumptions. A neighbourhood survey may suggest where cleaner transport or reduced unnecessary burning could help. Coal-producing regions can also be located on a map as a further learning task; use a current reliable map rather than guessing locations.
Quiz
Which set is obtained from petroleum?
Which are the three principal fossil-fuel groups described?
Why are fossil fuels classed as limited?
What is CNG in this lesson?
Which action usually reduces fossil-fuel use for a suitable short trip?
What happens when fossil fuels burn?
Practice Problems
- Make a table from a safe survey of at least five vehicle types and their reported fuels.
- Explain how long-buried remains lead to coal, petroleum and natural gas.
- Sort petrol, diesel and kerosene as petroleum products, then name two other main fossil fuels.
- Compare the uses of coal, natural gas, CNG and LPG.
- Explain why a cleaner fuel can still be non-renewable.
- Propose three realistic ways a household or school could reduce fossil-fuel use.
- Describe two effects of burning fossil fuels on air and one local observation you could investigate.
Key Takeaways
• Coal, petroleum and natural gas formed from buried remains over millions of years. • Petrol, diesel and kerosene come from petroleum; natural gas and coal have other important uses. • Fossil fuels are limited and burning them contributes to air pollution. • Walking, cycling, shared transport and suitable alternatives can reduce unnecessary fuel use.