First it was his world history class. Then he saw it in his economics class. And his world issues class. And his environment class. In total, 18-year-old McKenzie, a Northern Ontario high schooler, says he has had the film An Inconvenient Truth shown to him by four different teachers this year.

"I really don't understand why they keep showing it," says McKenzie (his parents asked that his last name not be used). "I've spoken to the principal about it, and he said that teachers are instructed to present it as a debate. But every time we've seen it, well, one teacher said this is basically a two-sided debate, but this movie really gives you the best idea of what's going on."

McKenzie says he has educated himself enough about both sides of the climate- change controversy to know that the Al Gore movie is too one-sided to be taught as fact. Even scientists who back Mr. Gore's message admit they're uncomfortable with liberties the politician takes with "science" in the film. But, McKenzie says most of his classmates are credulous. His teachers are not much more discerning. "They don't know there's another side to the argument," he says. McKenzie's mother was outraged to find out that Mr. Gore's film was being presented as fact in her son's classroom. "This is just being poured into kids' brains instead of letting them know there's a debate going on," she says. "An educational system falls down when they start taking one side."