Reviewing a high-school book in environmental science

Powerful Virtues,
Crippling Defects

William J. Bennetta

Kendall/Hunt's Global Science is something different. According to John W. Christensen -- the high-school teacher whose name appears on the book's title page -- Global Science has been written as a high-school book, and high-school students constitute its primary audience. Christensen told me this during a telephone conversation on 4 February. I had called him because I could not infer, and the book did not explicitly declare, who the primary audience was supposed to be.

"The book started out [in its 1981 and 1984 versions] as something for grades 10 to 12," Christensen said. "It was for schools that wanted to give a course beyond the usual sequence of biology, chemistry, physics. But since then, we've become aware of a new niche. Schools want to give a 9th-grade course that will be relevant and will encourage students to go farther in science. That's one of the things this new book [the 1991 version] is meant to do."

I must say that I cannot see Global Science as a book for 9th-graders, no matter what science courses they may have taken in middle-school grades. The text has passages that try to introduce basic concepts of biology and chemistry, but I do not think that those passages will enable a 9th-grader to understand the rather dense, deep material that constitutes the bulk of the book. In my judgment, making Global Science suitable for 9th-graders would require so much revision of the text that the result would be a different book altogether.

But what if I assume a more advanced audience -- say, students who already have completed a high-school course in biology, and maybe one in chemistry as well? Now the task of judging Global Science is harder, because this book has some powerful virtues and some crippling defects. Let me begin with some of the virtues:

• The text abounds with solid, knowledgeable explanations of technology. A wealth of information about commercial processes (especially processes for exploiting mineral resources) is presented competently and in ways that are appropriate for high-school juniors and seniors.

• Chapter 3 gives an admirable discussion of population dynamics. It tells of the relations between population and resources, it makes clear that the runaway increase in human numbers must be stopped, and it describes and illustrates contraceptive devices. I would like to see a comparable exposition in every life-science book, biology book and environmental-science book that is offered for use in public schools.

• The role of population growth in depleting resources or exacerbating environmental problems reappears in later parts of the book, serving as a unifying idea. See, for example, chapter 5 ("Food, Agriculture, and Population Interactions") or chapter 9 ("Water: Quantity and Quality").

• There are some good case studies. The one about the Everglades (in chapter 9) is a notably fine exposition of how a marvelous natural system was brought to ruin by human stupidity and greed. I am sorry that the book does not provide more such histories and does not recount any that involve the Japanese. Given the increasing prominence of Japan as an economic power, students should learn something about that country's recent practices with respect to, say, marine animals or tropical forests.

The principal flaws of Global Science are two:

First, too much of the book is outdated. Serious obsolescence -- meaning devotion to material that was timely 15 or 20 years ago -- is seen at many points in the text and in literature lists at the ends of chapters. Why would a textbook dated in 1991 cite Paul Ehrlich's The Population Bomb (issued in 1968) but ignore its successor, The Population Explosion (1990)? (For that matter, why would any text cite Jeremy Rifkin's Entropy: A New World View as if it were legitimate? Rifkin is a sensationalist who concocts silly, mass-market books about things that he does not understand. For some information about him and his products, see Stephen Jay Gould's article "On the Origin of Specious Critics" in the January-1985 issue of Discover, or see my own article "Where Does This Stuff Come From?" in Science 85, July-August 1985.)

Second, the text occasionally lapses into serious error, incoherence or confusion. I am not talking about isolated mistakes or cases of carelessness. I am referring to whole passages that are dreadful. Look at the confused stuff about organic evolution, starting on page 250. Worse, look at page 56 and the section "The Fundamental Laws and Principles of Human Ecology" -- an indiscriminate mixing of laws of nature (such as the first and second laws of thermodynamics) with subjective political statements. Examples of the latter include "All humans are created with an equal right to live in dignity and peace, and have a meaningful existence" or "All persons must be held responsible for their own pollution."

This is unforgivable. Although I may agree with some of the social and political ideas that are listed, I deplore the implication that they are equivalent, or even similar, to concepts derived from observations of nature. Like it or not, nature has nothing to say about equality or rights or the allocation of responsibility. Global Science, by mixing disparate classes of ideas, projects serious misimpressions.

In the end, the book's faults -- especially its obsolescence -- prevail over its better aspects. I cannot endorse Global Science.

Outdated Material,
Unfocused Writing

Max G. Rodel

Kendall/Hunt apparently has tried to create a text that would show young readers how mathematics and some principles of chemistry, physics, and geology can be applied to the analysis of environmental problems. The text touches on social issues, but always in the context of applying basic science.

In its organization, this book is somewhat different from typical environmental-science texts. It has only twelve long chapters, all focusing on aspects of energy and resource management. (Seven of the chapters have the word resource or resources or energy in their titles.) Each chapter begins with a list of at least two dozen vocabulary words, then a short set of questions. These items alert the student to the most important elements in the text that will follow. The text pages have margin-notes (which call more attention to important ideas) and numerous illustrations (which are widely variable in their quality).

Kendall/Hunt's writers present basic science by bringing it into their text wherever it fits with the topic at hand. Human reproductive biology, for example, is treated in the context of population dynamics and the controlling of human populations. Similarly, the mechanics of flowing water is in a discussion of economic mineralogy and the formation of ore deposits.

In addressing controversial social issues, the writers generally are equitable and avoid the ardent advocacy that is prominent in some other environmental-science books. (See the reviews of Prentice Hall's Environmental Science: The Way the World Works in The Textbook Letter, July-August 1990.) Chapter 3 of Global Science, for example, describes birth-control methods, shows illustrations of condoms, diaphragms and other devices, and then turns to a fairly even-handed treatment of the abortion issue. In Chapter 6 there is a lengthy, rather technical discussion of nuclear energy, concluding with a tabular summary of its advantages and disadvantages. Chapter 11 is devoted entirely to economics, then chapter 12 describes five different world-views. I did not sense a political agenda in these discussions.

A typical chapter concludes with a summary, a literature list, some questions and some problems. The problems are challenging -- solving them requires a thorough understanding of arithmetic, as well as knowledge of algebra and geometry.

Supplemental exercises, presented as worksheets, are scattered throughout the text. They usually require the application of mathematics and physics, and many of them are difficult. Exercises 2.1 and 2.4, for example, ask the student to analyze the behavior of hypothetical heat engines. Exercise 6.1 helps the student to practice the balancing of nuclear equations.

So far, so good. The good features of this textbook, however, are outweighed by the bad ones.

Similarly, the items cited in the book's literature lists date largely from the 1960s and l970s. Yes, the writers have added a number of more recent references, but not enough to keep Global Science from looking like something produced 15 years ago.

Another serious problem is the book's lack of a clearly defined audience. Though some parts of the text are suitable only for high-school seniors who have a real command of mathematics, other parts seem to have been written for elementary-school students. On page 7, for example, the writing is downright juvenile:

In 1957, a strange "star" appeared in the heavens. It was bright and clear. Unlike other stars, it moved rapidly and did not twinkle. It was called Sputnik and it wasn't a star!

A 5th-grader may keep reading, but most high-school students will soon go to sleep. So too with some of the illustrations. Page 38 shows a "cutesy" diagram of the ecological transformation of a body of fresh water, which changes from a "fish lake" to a "duck marsh" to a "frog meadow" and so on: There is a drawing of an animal for each stage. This seems right for Sesame Street, not high school -- the more so because the mechanism of the ecological succession is not explained. (And as if once were not enough, a closely similar diagram, with the same labels, is shown on page 507!)

Yet the book also has text passages, illustrations and exercises that seem to be for students in the upper grades of high school. See those complicated charts, on page 505, that relate water pollutants to some unstated property of "Cladophora" and "Tubificidae" and "Chironomus" and "Asellus," but do not even tell what "Cladophora" and those other things are. Or consider exercise 17 on page 391, in which the student must transform and then apply the equation T_e = 1/k ln [(Rk/r_o) + 1].

I must suspect that any student who is comfortable with the Sputnik passage will be badly discouraged by that exercise (and by others of comparable complexity), while a student who is comfortable with natural logarithms will be repelled by the book's juvenile aspects: Perhaps Kendall/Hunt's writers wanted Global Science be all things to all students. What they have produced is a book that seems to have no identifiable audience.

In sum, Global Science provides practical coverage of technical topics while avoiding the preaching and the moralizing that some other environmental-science texts favor. This textbook is out-of-date, however, and appears to be aimed at nobody ill particular. I cannot recommend it.

William J. Bennetta is a professional editor, a fellow of the California Academy of Sciences, the president of The Textbook League, and the editor of The Textbook Letter. He writes often about the propagation of quackery, false "science" and false "history" in schoolbooks.

Max Rodel is a consulting environmental chemist affiliated with Environmental Science Associates, in San Francisco. His principal professional interest is the chemistry of natural aquatic systems, including the fates of pollutants. He lives in Mill Valley, California, and he regularly reviews science textbooks for The Textbook Letter.

Addendum

Kendall/Hunt issued another version of Global Science in 1996. Reviews of the 1996 version appeared in TTL for November-December 1996.

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