John DeCicco: Bringing biofuels back to earth
A new piece on Energy Institute Research Professor John DeCicco's blog, Cars and Climate, explores the flow of greenhouse gas emissions and carbon dioxide during the life cycle of biofuels. It is excerpted below.
"After all that's been written about the pros and cons of biofuels over the years, it's fair to ask whether there's anything left to say. It turns out that there is, and a new insight comes from evaluating what actually happens on the earth, that is, on the land where the plants used to make biofuels are grown.
No one has previously done a careful before-and-after comparison of how the flows of CO2 between the land and the atmosphere change for a real-world case of burning a biofuel instead of a fossil fuel. The operative word here is flows, referring not only to the greenhouse gas (GHG) emissions flowing upward into the atmosphere but also to the downward flow of CO2 from the atmosphere into the biosphere as plants grow.
Our new study performed just such an evaluation, looking at the first-year operation of a particular corn ethanol facility and the farmland serving it. When tallying all of the key carbon flows for the processes directly involved -- including oil production, farming, petroleum refining, biorefining and fuel consumption -- the data show that substituting ethanol for gasoline resulted in no significant change in net CO2 emissions."
Read the rest on Cars and Climate.