All energy choices have strengths and weaknesses, and all have impacts on the environment. That is true of biofuels too.
For example, ethanol is completely domestic, and we don't fight wars to access the Iowa corn crop. Quite a strength.
But 40% of US corn and 14% of our soybean production is now consumed to make biofuels, a lot of biofuels. Corn farmers have been big winners from booming ethanol production. But not all impacts of ethanol are positive for all Americans.
Ethanol production increased from 13.3 billion gallons in 2010 to 13.9 billion gallons in 2011. Production is equal to nearly 10% of US gasoline consumption. http://www.eia.gov/biofuels/issuestrends/. Biodiesel production in 2011 was sharply up from 2010 and 2009 and nearly reached 1 billion gallons.
Corn farmers have been big winners from booming ethanol production, raising their incomes and the value of their land. But not all impacts of ethanol are positive. Diverting 40% of the corn crop to biofuels raises food prices, though by how much is contentious, raises feed costs for some farmers, and impacts water.
Corn consumes lots of water and run-off from corn fields can pollute waters. Indeed, the impact of corn ethanol production on water is likely greater than gas production--one more example of how the massive focus on gas drilling as supposedly the greatest threat to water is mistaken.