It turns out the use of biofuels may not be such a good alternative to gasoline after all. A recent article published in Science shows that biofuels may actually increase the the carbon-dioxide levels up to twice the current emissions of gasoline engines. Earlier studies neglected to account for changes in flora where large CO2 consumers such as forests and grasslands are replaced by ethanol crops. Even converting undeveloped land can release enough CO2 from the Earth that it will take between several decades to several centuries for the net effect to be neutralized.
Does this mean that all of these "green cars" that received a tax credit because for using biofuels should now owe tax money back to the government?