Bioethanol is a kind of alcohol made by fermenting and distilling sugars in plants, using starch-based plants, such as sugarcane and corn, and cellulosic plant resources such as wood materials and used paper. Plants are a focus of green energy because they absorb CO2 during the growth process. Even when the gas is released when they are burned, there is no change in the absolute volume of CO2. In Japan, technologies are being researched to make bioethanol from non-food plants, such as golf course grass and roadside weeds.