Petrol with up to ten percent ethanol (E10) is sold in some parts of Australia, mainly in Queensland. As ethanol is made from renewable resources, for example wheat and sugar cane, it can reduce the amount of greenhouse gases emitted from vehicles. However this depends on how the ethanol is made and the content of ethanol in the fuel. At ten percent, there is unlikely to be any greenhouse benefits. Ethanol can potentially reduce the amount of some air pollutants but increases others.
I understand the maximum blend in Europe is five percent ethanol (E5).