Nature is the world that exists without people: plants, animals, weather, mountains. The environment is everything around us: air, water, soil, people, animals. An ecosystem is the living things in one place and how they depend on each other. People say “Mother Nature” because nature gives life and food. Sources of energy are either renewable (they come back: sun, wind, water) or not renewable (they run out: coal, oil, natural gas). Fossil fuels – coal, oil and gas – formed from the remains of plants and animals that lived hundreds of millions of years ago. Advantages: easy to get, cheap, used for many things. Disadvantages: they pollute the air when burned, release greenhouse gases and will one day run out.
Worked examples
A forest is an ecosystem: trees give shelter to birds, birds spread seeds, and the soil feeds the trees. If one part disappears, the balance changes. Coal is a fossil fuel; sunlight is renewable. Burning coal pollutes the air, but a solar panel produces electricity without smoke.