Question: Which fossil fuel is considered the most abundant in the United States?
Paragraph: Coal also formed from once-living organisms. But the process is different. The formation of coal began when plants were buried under layers of sediment millions of years ago. Source: Amit John/Pearson India Education Services Pvt. Ltd The formation of coal also began millions of years ago, but when much of Earth’s surface was covered with shallow seas, deep forests, and wetlands. As plants died, the plant debris accumulated. Layers of mud, sediment, and additional plant material built up in thick layers over the years. As the layers piled up, the dead plant material was subjected to increased heat and pressure. But because there was very little oxygen, decomposition was slow. So the plant material retained most of its carbon. The first substance formed was peat. But more time, pressure, and heat transformed large amounts of peat into coal. Coal is burned in power plants to produce electricity. It is also a raw material needed to manufacture iron and steel products. The United States has large supplies of coal, but coal is the fossil fuel that produces the most pollution when burned. There are efforts to replace coal with cleaner fuels.
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