Biofuels are fuel made from living organism or from the waste they produce and include wood, biogas, ethanol, diesel or other liquid fuels made from processing plant material or waste oil. In recent years, the term “biofuel” has come to mean the last category – ethanol and diesel, made from crops including corn, sugarcane (the most efficient source of biofuels) and rapeseed. Biodiesel is made through a variety of chemical processes. In principle, biofuels are a way of reducing greenhouse gas emissions compared to conventional transport fuels and for many years have been thought to provide a small but fast-growing share of road-fuel supplies, and had been expected to make an important contribution to meeting growing fuel demand. However, the energy used in farming, processing and transporting the crops can make biofuels as polluting as petroleum-based fuels. In addition, there is mounting concern that biofuels may be contributing to food shortages