A University of Michigan researcher has found that nearly all of the studies used to promote biofuels as climate-friendly alternatives to petroleum fuels are flawed because they fail to correctly account for the carbon dioxide absorbed from the atmosphere when corn, soybeans and sugarcane are grown to make biofuels.
John DeCicco, a research professor at the University of Michigan’s Energy Institute, reviewed more than 100 papers published over more than two decades to reach his conclusion. If true, his findings undermine policies currently used to promote biofuels – such as the U.S. Renewable Fuel Standard and California’s Low-Carbon Fuel Standard – because biofuels actually worsen net emissions carbon dioxide.
“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 focus, he argues, should instead be on developing ways to remove carbon dioxide at faster rates and larger scales.
“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,” he adds.
DeCicco examined the four main approaches used to evaluate the carbon dioxide impact of liquid transportation fuels, including petroleum-based fuels and plant-based biofuels. He focused in particular on carbon footprinting, a type of lifecycle analysis proposed in the 1980s to evaluate the total emissions of carbon dioxide and other greenhouse gases emitted during the production and combustion of transportation fuels.
His analysis shows that these carbon footprint comparisons fail to properly reflect the dynamics of the terrestrial carbon cycle and miscount carbon dioxide uptake during plant growth. This process occurs on all productive lands, whether they are harvested for biofuel or not, he said.