“A lot of what’s in the film was already out there,” Ms. Leonard said, “but the style of the animation makes it easy to watch. It is a nice counterbalance to the starkness of the facts.”

The video certainly makes the facts stark and at times very political: “We’ll start with extraction, which is a fancy word for natural resource exploitation, which is a fancy word for trashing the planet,” she says at one point. “What this looks like is we chop down the trees, we blow up mountains to get the metals inside, we use up all the water and we wipe out the animals.”

Mark Lukach, who teaches global studies at Woodside Priory, a Catholic college-preparatory school in Portola Valley, Calif., acknowledged that the film is edgy, but said the 20-minute length gives students time to challenge it in class after viewing it.

“Compared to ‘An Inconvenient Truth,’ ” he said, referring to Al Gore’s one-and-a-half-hour documentary on climate change, “it is much shorter and easier to compact into a class segment. You can watch it and then segue into a discussion.”

Mr. Lukach’s students made a response video and posted it on YouTube, asking Ms. Leonard to scare them less and give them ideas on how to make things better. That in turn inspired high school students in Mendocino, Calif., to post an answer to Woodside, with suggested activities.

Dawn Zweig, who teaches environmental studies at the Putney School, a private academy in Vermont, said that the very reason the video appealed to teachers — it shows students how their own behavior is linked to what is happening across the globe — could also raise sensitive issues. She said students, particularly affluent ones, might take the critique personally. “If you offend a student, they turn off the learning button and then you won’t get anywhere,” Ms. Zweig said.

Image David Batker with his son Rafael de la Torre Batker, 9, who worried it might hurt the environment if he bought a new set of Legos. Credit... Kevin P. Casey for The New York Times

Sometimes teachers observe the opposite: children who become environmental advocates at home after seeing the video. After Jasmine Madavi, 18, saw it last year in Mr. Lukach’s class at Woodside Priory, she began nagging her parents to stop buying bottled water. Her mother resisted, saying that filtered tap water, Jasmine’s suggested alternative, would not taste as good. But Jasmine bought the filter on her own, and the household is now converted.