Entries range from 100 to more than 2,000 words. Some are complemented by black-and-white photographs and diagrams. Each entry is signed, and topical coverage includes a broad range of environmental perspectives, including scientific, political, and social issues. Most of the entries are followed by a brief bibliography. However, these bibliographies are inconsistent, some pointing to a large number of standard and useful sources, others leading the user to an odd selection of works that do not represent comprehensive or core treatments of the issue at hand. Additional sections include a brief (five-page) "Historical Chronology" of environmental events, a five-page chronology of "Environmental Legislation in the United States," organizations mentioned within the bibliographies accompanying encyclopedia entries, and an index to entries and terms.