What element is found in all known forms of life? Carbon! Scientists call carbon the chemical backbone of life on Earth. That’s because without carbon, there’s be no humans, animals, plants, microbes, or any other kind of life. In The Carbon Cycle: Track the Path of Life's Essential Element, young scientists explore how the first life forms that evolved on our planet consumed carbon and now, 4 billion years later, carbon is still the building block of all known forms of life. Carbon regulates the planet’s temperature, serves as the foundation of our food web, and provides the energy that fuels the global economy. Carbon is stored in rocks, sediment, the ocean, the atmosphere—and in every living thing, including people. Carbon rotates through these reservoirs in what we call the carbon cycle. This carbon cycle relies on balance, but certain human activities cause carbon dioxide to get released into the atmosphere, upsetting the careful equilibrium that keeps our climate healthy and habitable. Learn all about the carbon cycle and the human influence on that cycle through a compelling narrative, links to online resources, essential questions, text-to-world observations, hands-on STEM activities, and graphic-novel style illustrations and photographs. Additional materials include a glossary, a list of media for further learning, a selected bibliography, and index. All books are leveled for Guided Reading level and Lexile and align with Common Core State Standards and Next Generation Science Standards. All titles are available in paperback, hardcover, and ebook formats.