Imagine if your job was to work with a couple of thousand elementary school kids at the same time — to keep them on task, doing the same project, where everyone needed to be exactly in place for it all to work. “The teachers are always worried that it’s going to be chaos, that kids are going to cause all kinds of problems,” says Daniel Dancer. “But it never happens. There’s always love and joy present instead — it’s palpable how present it is.”

Dancer is a pioneer of what he calls sky art — if you watch this video you’ll see some of the amazing images he’s pulled off just in the last few months.

We at 350.org love his work, of course, because every image contains that nugget of science education provided by NASA’s Jim Hansen: that 350 is the most important number in the world, the boundary between beauty and desolation. But no one I know manages to get it across with more power and more subtlety.

An early fascination with the Nazca lines (the ancient drawings visible from above that mark the high desert of Peru), and a career as a photographer with a special passion for aerial work, led Dancer to his present work. He’s hired by school districts that write grants to raise the money for the art pieces; Dancer arrives, and the first job is to hold an assembly where he shows pictures of his past projects. “Once they realize what they can do, they’re all on the same page, they all want to do good, even the problem kids,” he explains.

And the kids, in turn, draw in the adults. The first image on the video is of a polar bear on a melting iceberg. And the man on the iceberg? That’s Maryland governor Martin O’Malley. “I’m not sure he quite knew what he was getting into,” says Dancer. “He said ‘I gotta leave in 20 minutes.’ I said, ‘we can do it.’ That’s the fastest I’ve ever worked.” Occasionally grownups balk: “I’ve been called into the principal’s office a couple of times for teaching the pledge of allegiance to the earth,” Dancer says. “But I think I have found an edge I can walk on with this that allows a lot of things to be said.”

When he began in 2000, Dancer found only two schools that wanted to participate. Last year he did 20 of the big pieces, including a giant one with 5,000 kids forming a windmill and tulips in the Dutch countryside. “You can literally do anything with this art form if you have enough help,” he says. The work itself is relatively simple: you start with an image, and you grid it out on graph paper so you can blow it up. But you have to know a few basic things: “one elementary school kid equals about three square feet,” for instance.

And you have to be able to convince kids that what they’re doing matters, that they’re part of making change. “Kids wake up in the morning, and they tell their mommy: ‘This is the most important day of my life,’” says Dancer. “And she’ll say, ‘Why?’ And they’ll say: ‘Today I’m going to be part of an alligator.’”