According to research, increasing the use of petrol and ethanol blends can reduce the carbon footprint of transport in the EU
A study commissioned by the European Committee for Standardization (CEN) investigated the costs and benefits of introducing a fuel containing 20% bioethanol, or E20. Bioethanol is a type of alcohol, derived from plants, considered to be a renewable fuel as it is made from plants. It is considered to be "greener" than fossil fuels, as it does not release additional carbon into the atmosphere. This is due to the fact that bioethanol is obtained from plants that absorb carbon dioxide present in the the atmosphere.
the CEN study found that while fuel consumption would go up if countries switched to using E20 fuel, due to the increased amount of ethanol, carbon dioxide emissions overall would go down 10% compared to all cars using E10. In the study, a scenario where the 27 EU countries and the UK adopted E20, would see a reduction in greenhouse gas emissions by the equivalent of 8.2% of current gasoline emission levels.
For more information on the study, see the related article on Horizon Magazine.