Each week, Paul Wood chats with a high-tech difference-maker. This week, meet EMMA MERCIER, a University of Illinois curriculum and instruction professor with a doctorate from Stanford. A native of Ireland, Mercier, 37, still eats meat sometimes, but teaches children about its impact on our environment, in terms of both the carbon and water it takes to produce. She and her graduate students have created the Food for Thought app, which aims to give seventh and eighth-graders insight into the food industry's impact on the environment. In her study on middle school eating habits, she found most skipped the broccoli option in favor of meat, often burgers. The app now has a brand-new iPad version just available in the App Store as of Friday.