Coal is a natural resource millions of years in the making. Since over 40 percent of the world’s electricity comes from burning coal, it remains an important, though sometimes controversial, energy source. The processes that transform organic remains into coal, coal mines, and the carbon cycle are important topics covered in this valuable volume. Readers will learn about the pollution attributed to the burning of coal as well as about coal alternatives. Graphic organizers, instructive photographs, and thoughtful sidebars help present a well-balanced look at this relevant and timely subject.