CHILDREN STILL HAVE THIS PASSION for the earth and the things that live on it," says Randi Hacker. "Instinctively they are connected to the planet in a way we adults are not." With partner Jackie Kaufman, Hacker has proved her point with P3, a children's environmental magazine that ranks among the fastest growing publications around. Since its launch a year ago, circulation has shot up from 3,000 to 20,000.

P3 (the name is code for Earth, the third planet from the sun) appears six times yearly and aims to engage and inform readers from ages 6 to 12 on environmental issues—the dwindling supply of fossil fuels, for example. Each issue packs 32 pages of eye-popping graphics, hip language, games and comics. Sent to home subscribers ($18 for 10 issues) and elementary schools across the U.S. and in nine other countries, P3 encourages activism. At the end of a story on the slaughter of African elephants by ivory poachers, the magazine urged kids to write to the U.N. Environment Program to "tell them you want elephants around when you grow up."

Hacker, 39, and Kaufman, 33, both from the New York City area, were free-lance writers who teamed up in the 1980s. The idea for P3 grew out of their concern for the environment and their experience in writing for kids. In 1989 the pair abandoned the big city for a log cabin in Vermont, settling on 13 acres in Montgomery (pop. 823). From their rustic "world headquarters," Hacker and Kaufman write and edit P3, assisted by up to seven part-time staffers.

Lauren Hutton and Sigourney Weaver are listed among P3's volunteer board of directors, and the (Barbra) Streisand Foundation has donated $6,000. But even with subsidies, the editors say they're $30,000 in debt, though they hope to break even soon with increased circulation and hoped-for corporate sponsorship. P3 "should be in every classroom," says board member Hutton. "If children understand [the environment] at an early age, maybe they'll put pressure on their teachers, their parents and themselves."