7Arlene Harper has dealt with big change before. In fourth grade, she came to the first day of school in new leg braces. But the changes that rock her world this year feel like a total earthquake.

Inspired by a social studies unit on our country's biggest social movements, and perhaps prompted by the cafeteria's overflowing garbage cans, Arlene and her friends launch a campaign to reduce their school's carbon footprint. Like most rebellions, they face stiff opposition, in this case from principal Musgrove and his love of budgets, order, and apparently, Styrofoam. But these mini versions of Rosa Parks, Susan B. Anthony, and Cesar Chavez are not deterred. They knock fists and pronounce, Si se peude!

Yes they can. They can get themselves in quite a heap of trouble. And while leading this revolution, Arlene finds herself marching farther away from the friend she always thought would be there.