Readers discover essential facts about the environment as they expand their knowledge of fossil fuels such as coal, oil, and natural gas. As the human population grows and technology advances, more energy is needed to power different products, such as cars, machines, and household appliances. The use of excessive fossil fuels is detrimental for the environment, whereas using renewable energy sources, such as sunlight, wind, and geothermal heat causes less destruction to the natural world. Readers learn these and other important facts with the help of a compelling, fact-filled narrative, detailed glossary, fact boxes, and creative design elements.