Most of the world's sugar comes from sugarcane. But the plant is so difficult to harvest that farmers often set their fields on fire first to get rid of leaves and unwanted pests. That's how most sugarcane is harvested in Florida, the largest producer of sugar in the US. Residents who live near the fields say the giant smoke clouds are is making them sick. The largest producer of sugar in the world, Brazil, has figured out how to harvest the crop without burns. Can the US do the same?