Errors and half truths (incomplete):

• Figure 1-13: People Overpopulation/Consumption Overpopulation (p. 18)
  "This model, developed in the early 1970s by biologist Paul Ehrlich... and physicist John Holdren, can be summarized in simplified form as Impact = Population x Affluence x Technology... Overpopulation... happens when people exceed the carrying capacity of an area..." (p. 18)

  Overpopulation is not a scientific term, since it cannot be rigorously defined or separated from the issue of poverty, the actual cause of human suffered discussed here. The model described by this formula and in the diagram is seriously flawed in its handling of "technology". Improved technology has been demonstrated to decrease environmental impact per unit GNP; thus, it might be more valid to divide by "technology" rather than multiply by it (assuming technology could be well quantified). Ehrlich's predictions regarding population growth and its consequences have been proven wrong, serving to discredit much of his hypotheses.

• (Paul R. Ehrlich and Anne H. Ehrlich): "Nevertheless, a few uninformed people claim that population growth is beneficial, the ozone hole is a hoax, global warming is too uncertain to justify action, the extinction of other organisms is no problem, and the degree of crowding possible in Hong Kong, Singapore, and the Netherlands can be accommodated over the entire planet. Julian Simon is the leading spokesperson for this view. He believes that a finite earth can hold an almost infinite number of people." (p. 22)

  This is a serious misrepresentation of the views of Simon and many others. Simon can hardly be described as "uninformed", when Ehrlich has lost wagers to Simon in predicting future commodity prices using their respective hypotheses on resource issues. Over 16,000 well-informed scientists have signed a petition stating that the scientific evidence regarding global warming is insufficient to justify action in the form of the Kyoto Protocol. Simon and other well-informed individuals do not claim that "an almost infinite" population can fit on the Earth. Rather, they claim that new resources will be recognized by free people and that economic transitions will mitigate population growth, among other things.

• (Paul R. Ehrlich and Anne H. Ehrlich): "He also has maintained that resources are getting cheaper because they are infinite in supply. He believes, incorrectly, that resources are infinitely subdivisible (for example, petroleum, once it is divided into atoms, is no longer petroleum)." (p. 22)

  These statements regarding Simon's position are false, so much so that it suggests that the Ehrlichs have never examined Simon's arguments. Simon points out (correctly) that most resources exist on Earth in significantly greater quantities than the currently known and economically recoverable amounts.

• (Paul R. Ehrlich and Anne H. Ehrlich): "The main problem now with oil is neither its supply nor its price, but the environmental costs of burning it and other fossil fuels, especially the injection of greenhouse gases into the atmosphere." (p. 23)

  This statement represents a significant concession by the Ehrlichs, whose position in the 1970s was that the world would be running out of oil in the 1990s, resulting in global conflicts and mass starvation in the industrialized nations.

• (Paul R. Ehrlich and Anne H. Ehrlich): "Nuclear power may cost fewer lives than coal if there are no major accidents; but the Chernobyl (which may eventually cost many more lives than the coal industry) and Three Mile Island accidents convinced the public that the risk was too high." (p. 23)

  The Three Mile Island accident caused zero deaths and zero injuries. The Chernobyl accident killed 31 people and has so far caused a few hundred additional cases of childhood thyroid disease (most of which would have been prevented had appropriate responses been implemented after the accident). Even including major accidents, nuclear power is orders of magnitude safer than coal or any other form of energy production. Note that the public was convinced the risk was too high, which contrasts with an accurate assessment of risk by experts.

• "The United States is the world's largest user (and waster) of energy." (p. 48)

  While it may be accurate to state that the largest absolute amount of energy is wasted in the United States, the preceding statement is incorrect if energy efficiency is considered.

• "Half-life can also be used to estimate how long a sample of a radioisotope must be stored in a safe enclosure before it decays to what is considered a safe level. A general rule of thumb is that this takes about ten half-lives." (p. 50)

  The risk associated with a radioisotope is a function of activity level which in turn is a function of both decay rate and quantity of radioisotope. It is erroneous to represent it as a function of half-life alone. Under this reasoning water would be dangerous forever because it has an infinite half-life.

• Figure 6-1 (p. 130)

  Choice of photograph is inappropriate for a high school text. Similarly, much of the discussion regarding birth control methods is also inappropriate for a high school text.

• "The world's annual population growth rate dropped 18% between 1965 and 1993... This is good news, but during the same period the population base rose by 72%... This 18% drop in the growth rate of population is akin to learning that the truck heading straight at you has slowed from 100 kilometers per hour to 82 kilometers per hour while its weight has increased by almost three-fourths." (p. 131)

  This analogy is misleading. First, it implies that both absolute population and population growth rates are potentially disasterous, which is not established apart from issues of poverty. Second, it does a poor job of conflating these characteristics. A very large motionless truck poses little threat, but Miller would likely claim that a very large population is a problem even with no population growth.

• "Various factors contributed to this decline in [U.S. total fertility rate]: Widespread use of effective birth control methods. Availability of legal abortions. Social attitudes favoring smaller families. Greater social acceptance of childless couples. Increasing cost of raising a family... The rise in the average age at marriage between 1958 and 1991... More women working outside the home... Delayed reproduction..." (p. 133)

  This listing fails to acknowledge the widely varying significance of these factors. Legalization of abortion, for example, came almost at the end of the fertility decline from 1955 to 1975. "Social acceptance of childless couples" has been increasing probably since early in the century.

• Figure 6-19 (p. 145)

  Figure significantly exaggerates the area covered by urbanization.

• Figures 6-28 (p. 155) and 6-29 (p. 156)

  These models of population/resource interaction are seriously flawed and have been discredited.

• Figure 8-11: "Control room of a nuclear power plant. Watching these indicators is such a boring job that government investigators have found some operators asleep, and in one case they found the control room empty. (p. 206)

  It is unclear why the author believes the most important aspect of a control room is that there have been isolated cases where operators were inattentive. It is, however, noteworthy that the nature of nuclear power is such that it is the safest form of power production despite such occurrences.

• Table 9-1: "Major Classes of Air Pollutants: ...carbon dioxide..." (p. 215)

  Carbon dioxide is not a pollutant but a naturally occurring substance.

• "2040 A.D.: Hard Times on Planet Earth" (p. 234)

  This "fictional worst-case" scenario is orders of magnitude more extreme than any worst-case scenario put forth by the scientific community. It does not belong in a science textbook.

• "Collectively, these gases, known as greenhouse gases, act somewhat like the glass panes of a greenhouse (or of a car parked in the sun with its windows rolled up): They allow light, infrared radiation, and some ultraviolet radiation from the sun...to pass through the troposphere. The earth's surface absorbs much of this solar energy and degrades it to longer, infrared radiation--that is, heat--which then rises into the troposphere... Some of this heat escapes into space; some is absorbed by molecules of greenhouse gases, warming the air; and some radiates back toward the earth's surface. This trapping of heat in the troposphere is called the greenhouse effect..." (p. 237)

  This discussion promotes misconceptions regarding the greenhouse effect. Greenhouses and parked cars are heated primarily because the windows prevent convection with surrounding air, not because of the greenhouse effect. Some wavelenths of infrared radiation from the Sun are mostly absorbed by the atmosphere before reaching the ground. The Earth's surface does not "degrade" radiant energy; rather, it warms as a result of absorption of radiant energy. The Earth in turn radiates more energy than before it was warmed. Infrared radiation emitted by the Earth's surface does not "rise" (a term which erroneously implies convection) but radiates in all directions. The statement "Some of this [rising] heat... radiates back toward the earth's surface" does not make sense. Heat is not trapped in the troposphere; this erroneously implies prevention of convection or conduction. The discussion is flawed in confusing thermal energy (heat) with infrared radiation.

• Figure 10-6: "When greenhouse gases build up in the atmosphere, more heat is trapped near the earth's surface. Ocean surface temperatures rise, more water vapor enters the atmosphere, and the earth's surface temperature increases." (p. 238)

  It is confusing to say that greenhouse gases "trap" heat. The Earth's temperature does not necessarily increase as a result of greater quantities of atmospheric water vapor. More water vapor may lead to greater cloud cover, decreasing the Earth's albedo and decreasing its temperature.

• "Estimated changes in the levels of tropospheric CO₂ (Figure 10-8) correlate closely with estimated variations in the earth's mean surface temperature.
  Figure 10-8: "...Changes in tropospheric levels of carbon dioxide, a major greenhouse gas, correlate closely with changes in the earth's mean surface temperature and thus its climate, although other factors also influence global climate." (p. 239)

  Other geological investigations suggest that past temperatures are poorly correlated with carbon dioxide levels.

• "Eight of the 13 years from 1980 to 1992 were among the hottest in the 110-year recorded history of land-surface temperature measurements, and 1990 was the hottest of all." (p. 239)

  The stated results are from a particular weighted average of a particular subset of global recording station temperatures. This must be distinguished from directly representing the "history of land-surface temperature measurements", since the process of selecting these stations has been questioned by some reviewers.

• Figure 10-9a: "Carbon dioxide...contributes about 55% to global warming from greenhouse gases produced by human activities. Industrial countries account for about 76% of annual emissions. The main sources are fossil-fuel burning (67%) and land clearing and burning (33%). CO₂ remains in the atmosphere for 50 to 500 years." (p. 240)

  Contribution from land clearing and burning is exaggerated, and contribution from cement production (3%) is ignored. Basis for the atmospheric lifetime of carbon dioxide is questionable, given that 40% of anthropogenic carbon dioxide emissions since 1950 have not remained in the atmosphere.

• Figure 10-9b, Chlorofluorocarbons, Figure 10-9c, Methane, and Figure 10-9d, Nitrous oxide (p. 240)

  These figures are poorly represented by the graphs, which uses various scales to depict a 3% increase and a 100% increase as similar upward slopes.

• "Rising sea level... One comedian jokes of plans to buy land in Kansas because it will probably become valuable beachfront property; another boasts she isn't worried because she lives in a houseboat--the 'Noah strategy'." (p. 245)

  Not scientific evidence.

• Figure 19-5: "The end of the petroleum age is in sight. These two curves show that the world's known petroleum reserves will be 80% depleted between 2025 and 2035, depending on how fast this oil is used." (p. 519)

  This data is incorrect. The graph shown here was produced in the 1960s with projections from that time forward using flawed models. Actual rate of increase in petroleum consumption has been slower than depicted, and known reserves of petroleum has significantly increased in the intervening decades.

© 2002 by Wm. Robert Johnston.
Last modified 24 May 2002.
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