i

BRUCE GERVAIS

CALIFORNIA STATE UNIVERSITY, SACRAMENTO

ii

Vice President, Editorial: Charles Linsmeier

Associate Publisher: Steven Rigolosi

Marketing Manager: Taryn Burns

Developmental Editor: Donald Gecewicz

Media Editor: Lukia Kliossis

Market Development: Stephanie Ellis and Burrston House, Ltd.

Photo Editor: Sheena Goldstein

Photo Researcher: Jerry Marshall

Art Director: Diana Blume

Cover and Text Designer: Tom Carling, Carling Design Inc.

Copy Editor: Norma Sims Roche

Project Editor: Enrico Bruno

Managing Editor: Lisa Kinne

Illustrations: Precision Graphics; Mapping Specialists

Art Manager: Matthew McAdams

Production Coordinator: Susan Wein

Composition: Tom Carling; codeMantra

Printing and Binding: Quad/Graphics

Cover Art: Tennessee Cove, Marin Headlands, © 2013 by Tom Killion

Library of Congress Control Number: 2014945391

ISBN-13: 978-1-4641-0664-4

ISBN-10: 1-4641-0664-9

© 2015 by W. H. Freeman and Company

All rights reserved

Printed in the United States of America

First printing

W. H. Freeman and Company

41 Madison Avenue

New York, NY 10010

www.whfreeman.com

iii

For Nancy, Katherine, and Natalie

iv

Chapter GT, icon page 27: © Jumper/Photodisc/Getty Images; Chapter 1, icon page 50: NASA Ozone Watch; Chapter 2, icon page 84: © Harald Sund/Stockbyte/Getty Images; Chapter 3, icon page 116: © Erkki Makkonen/E+/Getty Images; Chapter 4, icon page 148: © Frank Krahmer/Digital Vision/Getty Images; Chapter 5, icon page 183: Image Science and Analysis Laboratory, NASA-Johnson Space Center (ISS007-E-14887); Chapter 6, icon page 214: Bruce Gervais; Chapter 7, icon page 247: © Ethan Daniels/Shutterstock.com; Chapter 8, icon page 285: © Nicholas James McCollum/Flickr Open/Getty Images; Chapter 9, icon page 318: © David Palmer/E+/Getty Images; Chapter 10, icon page 351: © 2011 Ferdi Rizkiyanto; Chapter 11, icon page 377: © Jason Reed/Photodisc/Getty Images; Chapter 12, icon page 409: Bartosz Hadyniak/Getty Images; Chapter 13, icon page 434: © Jon Mullen/E+/Getty Images; Chapter 14, icon page 468: © Stocktrek Images/Getty Images; Chapter 15, icon page 500: fotoVoyager/Getty Images; Chapter 16, icon page 534: U.S. Dept. of the Interior/Bureau of Reclamation; Chapter 17, icon page 568: NASA World Wind using data from NASA’s Earth Observatory; Chapter 18, icon page 596: © David Gomez/E+/Getty Images; Chapter 19, icon page 625: Dave & Les Jacobs/Blend Images/Getty Images

v