For years, biofuels have been touted as a greener, cleaner alternative to petroleum-based fuels. Turns out, they're not.

A study recently published by the University of Michigan paints a much different picture than most Americans have been led to believe.

The notion was simple: Bio-based ethanol was a cleaner and more sustainable fuel. The reality? Biofuels cause more emissions of climate change-causing carbon dioxide than gasoline, according to the study from U-M Energy Institute research professor John DeCicco.

"This pulls the rug out from under over a decade’s worth of public policy in this area," DeCicco said.

To read the full story and link to the report, see the Detroit News story here.