Plastic has a huge carbon footprint: Producing the petroleum-based material accounts for at least 100 milion tons of carbon emissions each year. Now, a team of researchers at the University of Wisconsin in Madison has invented an inexpensive way to make plastic with a much lighter touch, from sugar and corncobs. If it can be made cheaply enough, the material could one day replace one of the world’s most common plastics—polyethylene terephthalate (PET)—found in food packaging, soda bottles, and even polyester fabric.