This unique addition to reference literature provides an introduction to the major concepts and contemporary issues that are essential for students of environmental science and environmental studies to know. With over 200 entries authored by world-class names like Anthony Brazel, John Day and Edward Keller, this text is divided into six sections: Environmental Science, Environments, Paradigms & Concepts, Processes & Dynamics, Scales & Techniques, and Environmental Issues.
The atmosphere is a layer of gases (and liquids/particles) surrounding the Earth's surface held in place by gravity. The atmosphere is composed of 78% nitrogen, 21% oxygen, 0.97% argon, 0.04% carbon dioxide, and small amounts of other gases and water vapour. The atmosphere shields the planet by reducing temperature extremes between day and night and by absorbing dangerous Sun's rays. There exists no definite boundary between outer space and the atmosphere. Three-quarters of the atmosphere's mass is within 11 km of the surface. The average temperature of the atmosphere at the surface of Earth is 15°C (ca. 60°F). Generally, atmospheric pressure and mass drop by 50% at an altitude of about 5 km. At sea level, the average [Page 88]atmospheric pressure is about 101.3 kilopascals ...