Coal

Coal is a black or dark brown rock that burns easily and gives off heat and energy. It is one of the most important fossil fuels, along with oil and natural gas. People have used coal for hundreds of years to warm homes, run trains and ships, and make electricity for cities. Although it has helped build modern life, coal also creates smoke and gases that can harm the environment.

Coal formed long ago, millions of years before humans existed. Back then, thick forests grew in low, swampy areas. When these plants died, they fell into water and were covered by mud and sand. Over millions of years, the pressure from new layers of earth and the heat inside the planet slowly turned the dead plants into coal. This process is called carbonization. The deeper the coal forms underground, the harder and more energy-rich it becomes.

There are four main types of coal: peat, lignite, bituminous, and anthracite. Peat is the softest and has the least energy, while anthracite is the hardest and burns the cleanest. Bituminous coal is the most common and is used to produce electricity in power plants. Lignite is brownish and is often found near the surface, making it easier to mine but less efficient as a fuel.

Coal is mainly used to make electricity. In a power plant, coal is burned in large furnaces to heat water into steam. The steam turns a turbine, which drives a generator that produces electricity. Coal is also used in some industries, such as steel-making, where it helps melt iron ore to form metal. However, as the world learns more about climate change, people are looking for cleaner energy sources like solar and wind power.

Mining coal can be done in two main ways: surface mining and underground mining. Surface mining removes layers of soil and rock to reach coal near the top, while underground mining digs deep tunnels. Both methods can damage the land and release dust or gases into the air. After mining, the land can be restored by planting trees and grass to reduce harm to nature.

Today, many countries are working to use less coal because burning it releases carbon dioxide — a gas that warms earth’s atmosphere. Some power plants use special filters or new technology to reduce pollution, but the best solution is to shift toward renewable energy. Still, coal remains an important part of energy history and science, showing how ancient plants continue to power the modern world.