Texas high school biology textbooks battles are once again in progress in Austin, with lines drawn between those who want textbook material based only on established mainstream science and those who are anti-science. As an evangelical Christian and a botany professor at Hardin-Simmons University in Abilene, Texas, I am all too familiar with the battle for scientific authenticity in our state’s textbooks.
The Texas State Board of Education (SBOE) wields an enormous influence over which textbooks are adopted by school districts in Texas. And because the Texas market for public school textbooks is one of the country’s largest, publishers use the curriculum and content from Texas books in those they print for the rest of the nation. For this reason, what happens in Texas doesn’t stay in Texas. This is why it is so important that we ensure that publishers produce books based on mainstream science.
Over the last few weeks of hearings on science textbooks, there has been a strong push from anti-science activists and Creationists to weaken the teaching of not only evolution but climate change. We ought to be teaching our children the well-established science of climate change, since their generation will feel the effects more than our own. But some of the reviewers, whose critiques factor into the scores that textbooks receive, don’t agree with the scientific consensus on climate change. They may not have any credentials, but their opinions can bring down the score of a top-notch textbook, influencing what the publishers print, and potentially even blocking its use in public schools in Texas (and, by extension, around the country).
One of these reviewers is Ray Bohlin, vice president for Probe Ministries, a Plano, Texas-based evangelical Christian ministry that rejects evolution. He has written a review of a climate change case study in the best-selling Pearson/Prentice-Hall biology textbook. The climate change discussion in the text is thorough and thoughtful, and it sticks to mainstream science. Bohlin objects to the text in several places. As a botanist and as an evangelical Christian, I believe that science and faith can be compatible. I would like to offer my rebuttal to his arguments.
In his critique, Bohlin states that “No mention is made of the benefit to plants of higher CO2 concentrations” and that “plants always grow better under higher CO2 levels.” This is an uninformed generalization. Plant biologists have only begun to study the effects of elevated CO2 levels on plant growth. Given our understanding of plant physiology and ecology, we can confidently predict that plants in general will find environments with elevated CO2 levels more favorable for growth.
But we also know of limiting factors that make Bohlin’s statement misleading. For one, plants don’t grow in a vacuum, so without considering the host of other external environmental variables — many of which are a direct result of ongoing climate change — one cannot simply claim that plants always grow better if they have more CO2 available. A contributing reason for the uncertainty lies in how plants operate; most plant species use the C3 photosynthesis pathway, and the enzyme those plants use for CO2 uptake seems to be poorly designed. An increase in CO2 availability may, in fact, benefit those plants, but as I said before, no plant grows in a vacuum. Plant biologists don’t know yet how the current and future effects of climate change will interact with higher levels of CO2. Insects and other organisms that attack crop plants will likely thrive and increase in a warmer environment, and the same goes for the weeds that compete with crop plants for nutrients like nitrogen. There is a growing body of research that suggests any benefits in growth from elevated CO2 may be limited by nutrient availability and the effects of air pollution. Finally, increased levels of CO2 will not be of much benefit to plants that grow in regions that are predicted to become much drier due to the effects of climate change.
This discussion is a fine one to have with my students, and with anyone interested in the subject, but by submitting his critique, Bohlin is jeopardizing the chances of the Texas Board of Education publishing a sound scientific text. For Bohlin to suggest including a statement that “plants will always grow better with more CO2 available” in the Pearson/Prentice-Hall biology textbook is misleading and, in all honesty, irresponsible without a presentation of all the additional physiological, ecological, and climate-related facts that must be considered.
I can’t speak for Ray Bohlin, but perhaps his attempts to edit out sound science are based on fear that I’m threatening his view of Christianity. As a Christian, I don’t want to be prevented from telling the truth to our children about what we are doing to God’s creation. Our textbooks need to provide students with the complete scientific discussion, rather than being a political pawn for the anti-science crowd to block education.
Dr. Rick Hammer is a professor of botany, ecology, and environmental ethics at Hardin-Simmons University.
Image: Pile of textbooks, Skylines / Shutterstock.com