MTV News reports that Hilary Duff is no longer using confetti at her concerts after learning during her environmental science class on Harvard online that the excess paper is bad for the environment. “It’s so weird now how much I conserve,” she said. “I turn the lights out, and no more confetti, because that’s not recyclable. I did the math for the amount we used, multiplied by 36 shows? We don’t need it.” The teen queen admits taking the class is really hard with her schedule, since she has to read 50 pages three times a week, but she loves what she’s learned “about the ozone layer, about waste management.” “It’s so fun!” she said.