Contrary to popular ‘green’ beliefs, a study funded by the US federal government argues that corn-based biofuels are actually worse for the environment than gasoline, as they emit more greenhouse gasses and deplete soil carbon.
The $500,000 peer-reviewed analysis by the University of
Nebraska-Lincoln, published in an issue of the journal Nature
Climate Change, claims that cellulosic biofuels like ethanol,
produced from residue, the byproduct of harvested corn (left-over
leaves, cobs etc.) lead to a 7-percent increase in emissions, as
well as 62 grams above the 60-percent reduction in greenhouse gas
emissions stipulated in the law on energy targets of 2007.
This is a setback for those lobbying for cleaner fuels, who wish to combat climate change. The federal government has been trying to push through mandates for increasing ethanol production to promote the idea of clean alternatives to gasoline. They invested over $1 billion in federal funds to support cellulosic biofuel research. But ethanol-based fuel alternatives have so far been a more expensive, cumbersome venture.
This should make farmers happy, as soil erosion has always been a problem, as well as the issue of retaining residue for nourishing and preserving soil quality.
According to experts in the field, the research is long overdue and is the first attempt to quantify the effect of ethanol-based biofuel on carbon depletion in soil. It looked at production in 12 Corn Belt states.
The key conclusion is that when left to be absorbed naturally by the soil, the leaves, stalks and cobs are more beneficial for the soil than when it is later burned as fuel and the residue gives off carbon into the atmosphere. As a result, the study concludes the process contributes to global warming.
"If less residue is removed, there is less decrease in soil carbon, but it results in a smaller biofuel energy yield," Adam Liska, the professor in charge of the study said, adding that the results of the study were in line with his expectations and that he’s “amazed [the findings have] not come out more solidly until now.”
As a preventive measure against depriving the soil of carbon it gets from corn residue – and to reduce carbon emissions - the research suggests planting more crops to give the earth the carbon it needs; it also talks of using alternative feed stocks and sources of residue, as well as harnessing more electricity from carbon-fuel stations, as opposed to coal-operated ones.
The study received a swift response from government officials and oil businesses, who say the research is flawed, as it uses scenarios that are firstly too simplistic, because they don’t account for variations in carbon depletion from soil in a given field; secondly, they are seen as too extreme in overestimating how much residue is removed.
According to Jan Koninckx, who is the global business director for bio refineries at DuPont, a chemical company, “no responsible farmer or business would ever employ [the study’s suggestions], because it would ruin both the land and the long-term supply of feedstock. It makes no agronomic or business sense.”
But Liska believes that this is, in fact, the first study that got the carbon depletion math as close to the truth as possible.
And, as professor David Tilman of the University of Minnesota said in support of the study: “It will be very hard to make a biofuel that has a better greenhouse gas impact than gasoline using corn residue,” as cited by The Associated Press.