Biofuels are a renewable energy source, made from organic matter or wastes, that can play a valuable role in reducing carbon dioxide emissions. Biofuels are one of the largest sources of renewable energy in use today. In the transport sector, they are blended with existing fuels such as gasoline and diesel. In the future, they can be particularly important to help decarbonise the aviation, marine and heavy-duty road transport sectors.Biofuels can be produced from organic matter, or biomass, such as corn or sugar, vegetable oils or waste feedstocks. As biofuels emit less carbon dioxide (CO2) than conventional fuels they can be blended with existing fuels as an effective way of reducing CO2 emissions in the transport sector. The use of biofuels have grown over the past decade, driven largely by the introduction of new energy policies in Europe, the USA and Brazil that call for more renewable, lower-carbon fuels for transport. Today biofuels represent around 3% of road transport fuels in use around the world.most biofuels are produced from agricultural crops and are called conventional biofuels. New technologies and processes that produce fuels from waste, inedible crops or forestry products are being developed and these fuels are known as advanced, or second-generation biofuels. Advanced biofuels are likely to become the primary form of biofuels in the future as they can improve their sustainability.