I studied this book independently for the AP environmental science exam. It is definitely well written and delineates many concepts in the test in a simple easy to learn manner. Unfortunately, it is a short book and only contains about 3/5 of what you need to know to get a perfect score. I assume that this would probably work if someone had taken a class as well, but on its own this will only get you a 3, tops. I answered the questions on the topics found in the book easily, but about 2/5 of the test were on concepts not in the book. Getting a 3 is pretty good considering my only exposure to this topic was in this very short study guide, but unfortunately the college I'm going to accepts no less than a 4, and my efforts were thus meaningless.
Nonetheless, I reccomend this book, but only in addition to other sources or an environmental science/studies class. This book only has 3/5 of what you need to know, but again, that 3/5 is extremely well presented.