Source: University of Michigan press release — which begins with this:
Nearly all of the studies used to promote biofuels as climate-friendly alternatives to petroleum fuels are flawed and need to be redone, according to a University of Michigan researcher who reviewed more than 100 papers published over more than two decades.
Once the erroneous methodology is corrected, the results will likely show that policies used to promote biofuels—such as the U.S. Renewable Fuel Standard and California’s Low-Carbon Fuel Standard—actually make matters worse when it comes to limiting net emissions of climate-warming carbon dioxide gas.
The main problem with existing studies is that they fail to correctly account for the carbon dioxide absorbed from the atmosphere when corn, soybeans and sugarcane are grown to make biofuels, said John DeCicco, a research professor at U-M’s Energy Institute.
“Almost all of the fields used to produce biofuels were already being used to produce crops for food, so there is no significant increase in the amount of carbon dioxide being removed from the atmosphere. Therefore, there’s no climate benefit,” said DeCicco, the author of an advanced review of the topic in the current issue of Wiley Interdisciplinary Reviews: Energy and Environment.
“The real challenge is to develop ways of removing carbon dioxide at faster rates and larger scales than is accomplished by established agricultural and forestry activities. By focusing more on increasing net carbon dioxide uptake, we can shape more effective climate policies that counterbalance emissions from the combustion of gasoline and other liquid fuels.”
The DeCicco paper The liquid carbon challenge: evolving views on transportation fuels and climate is a valuable resource on biofuels. The paper is blessedly OPEN ACCESS.
WIREs Energy Environ 2015, 4:98–114. doi: 10.1002/wene.133
I recommend a careful read of DeCicco. For a one-graphic-summary I chose Figure 4 which shows that biofuels are not significant contributors to decarbonization if indirect land-use change (ILUC) is “correctly” accounted.