Biofuel : boon or bane

Biofuel usage is increasing globally and the number of biorefineries are increasing exponentially.Biofuels are considered to be eco-friendly and to reduce the green house effect and provide lesser dependence on fossil fuels. With petroleum prices shooting up to $100 per barrel there is growing dependence on biofuels. Countries like US, Brazil , China are producing biofuels with other countries slowly joining them. In US biofuels are mainy produced from Corn (Maize).In Brazil it is from sugarcane and in India it is from Jatropha plant. In recent time , bioethonol are been challenged for causing more green house effect than the fossil fuels they replace.The Feb 2008 Science issue reports that biofuel growing acreage can create twice as much as harm than other green house sources