Describes an initiative to create a thesaurus of environmental terms to aid electronic search and retrieval. Link to the thesaurus, project directory, and documentation.

Find a definition of the planetary cover that is composed of multiple gases. Discusses how humans affect its conditions.

Brief period of geologic time characterized by the appearance of modern day plants and animals.

Covers the properties, discovery, and effects of this form of energy. See photos and illustrations.

Learn how weather, temperature, glaciers, and other natural processes breakdown rocks and soil.

Describes the rock that formed at the bottom of evaporated seas. Learn about limestone, gypsum, and dolomite.

Covers the use of chemical techniques to study the occurrence of elements in the earth's crust. Includes environmental and environmental issues.

See photos and detailed descriptions of how surface and ocean floor surfaces are mapped and studied.

Provides an overview of the history, methods, and focus of this field of physics.

Find out how deposits on and movement of the earth's plates produce mountain ranges.

Learn about the discovery of natural steam an its use as an alternative fuel.

Details the conditions that create the greenhouse effect, and the role of carbon dioxide and methane gases.

Describes the atmospheric condition created by an overabundance of carbon dioxide, methane, and ozone.

Details the phenomena claimed to occur once every 150 million years, and details the Quarternary period.

Virtual encyclopedia entry describes the chemical make-up, various uses, and potential hazards, of this oxygen based gas.

Provides an introductory explanation of the atmospheric layer in which oxygen and sunlight make ozone. Includes links to ozone-related news.

Provides an introductory overview and journal links related to the study of changes in the Earth's climates through out time.

Explains what an "ice age" is, as well as the difference between a "long" and "short" ice age, or glaciation. The last glaciation in North America is often capitalized.

Learn when Earth experienced ice ages in the last billion years of which there have been four intervals, with the last being during the Ordovician and Silurian periods.

Answers the question "why do Ice Ages occur?" in two parts, addressing the reason why there have been four such intervals and what makes them advance and retreat.