"When you do that, you stop becoming a teacher and start becoming an advocate," said Colley, who considers Gore's movie "a political statement."
"Under no circumstances would I pull my daughter out of her science class. She can get the other side of the argument at home," he said. "But I am concerned that there are 29 kids in that class walking away thinking that they know everything there is to know about global warming."
The Midvale science teacher did not return telephone calls, perhaps a sign of just how touchy the subject of climate change can become in the public school classroom, a place where contending public opinions often color the core curriculum. One science education specialist said the study of carbon emissions on the earth's climate is so vast, and involves the interplay of so many complex scientific disciplines, that it leaves even the best teachers almost helpless in offering useful lessons.
The choice isn't left to Utah science teachers. The state's standards of secondary core science curriculum expect that Utah science teachers introduce the topic, if only because students are expected to understand it to a degree. So science teachers walk the line, risking charges that their approach gives one side of the debate too much credence, or none at all.
With the educational debate over evolution subsided for now after several court rulings that "intelligent design" did not qualify as a science acceptable for classroom instruction, some have switched battlefields. Early last year, an evangelical Christian parent of seven in Federal Way, Wash., objected to a screening of "An Inconvenient Truth" in his daughter's seventh-grade science class on grounds that the film ran contrary to his religious beliefs.
Colley's objections, he said, are science-based. In a three-page objection sent to his daughter's science teacher, the Sandy businessman and father to eight listed and referenced several scientists and scientific organizations, along with their arguments, taking issue with Gore's thesis that human activity is the culprit behind recent changes in the Earth's climate. Like many global warming skeptics, Colley believes climate change is real, but only natural as evidenced by the ice age. What he won't concede is that carbon emissions are the cause.
"We may be contributing 1 percent to global warming. It's largely due to solar activity, and there's not a thing we can do about it," Colley said. "The polar caps on Mars are melting, and there's not an SUV or smokestack in sight."
As it turns out, state curriculum makes no declarations about naming and teaching climate change's exact causes. "You'll notice we don't say anywhere that humans are warming up the atmosphere," said Barbara Gentry, secondary science teacher specialist for the Jordan School District. "Students are merely asked to investigate or research the effects of global changes on earth systems."
It's assumed, then, that students examine evidence and data for themselves and reach their own conclusions. At the same time, there's no requirement that science teachers give equal time to scientists who interpret the data differently. Presenting "both sides" of the debate would be appropriate, Gentry said, but not altogether necessary.
"It's very difficult to find materials on the other side of the debate that are science-based," Gentry said. "That comment's going to get me into trouble, but it's true.
"Yes, a good teacher would present all the different ways in which we know why the climate changes. At the same time, current data shows that our climate has never changed this fast before."
The American Association for the Advancement of Science, the American Geophysical Union and The American Meteorological Society all agree that carbon emissions have changed the climate. The National Academy of Sciences issued a report seven years ago stating that, "Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise."
That doesn't satisfy Colley, who marshals "dissident" scientists such as Bob Carter of the Marine Geophysical Laboratory at James Cook University in Queensland, Australia.
Eugenie Scott, executive director of the National Center for Science Education in Oakland, Calif., said that in general, science teachers follow the lead of professional and university-level scientists in teaching a subject, such as evolution, that generates controversy outside the classroom. If university-level scientists teach evolution as a matter of accepted scientific theory, teachers at all levels usually follow suit. Teachers at the secondary level should have little or no reservations about teaching students that carbon emissions generated by humans influence climate change, she said.
"If evolution carries 99 percent unanimity among scientists, then climate change as being caused by human activity has a rate of 85 to 90 percent unanimity among scientists," she said.
"Where legitimate science-based positions on an issue exist, it's appropriate for students to know there are different views. But when you have an extremely complex scientific problem such as climate change that has components from virtually every science, you can think of it's almost ludicrous to expect high school or middle school students to analyze models by different sides to make arguments when even professional statisticians and mathematicians argue over the appropriateness of some models."
Don't fault Clayton Middle School science teacher Adrian Bancroft for trying. His students analyze data and information on the current climate without any commentary or interpretation. They view Gore's film, and another from the opposite view titled "The Greening of the Planet Earth," which argues that increased carbon dioxide levels in the atmosphere will lead to more oxygen-producing plants and balance out the carbon dioxide we produce.
"I never tell them what my opinions are until after they've turned in their position papers," he said.
True to his middle-of-the-road approach to teaching climate change, Bancroft's opinion also falls somewhere in the middle.
"As humans we're definitely affecting the temperature of the climate, but I don't know if it's to the degree that Al Gore claims," he said. "I should also say that I believe that if we stop carbon emissions today that would be a good thing."