The conversion of land for growing could increase greenhouse gas emissions.
A recent study conducted by the University and The Nature Conservatory shows that conversion of land to produce biofuels would lead to increased greenhouse gas emissions, actually furthering global climate change.
Stephen Polasky, an applied economics professor and co-author of the study, said it was important to address the problem of “carbon debt” – the amount of carbon released in the process of converting natural landscapes into cropland.
Producing biofuels creates more carbon emissions than the use of biofuels saves, Polasky said.
“We felt it was a missing aspect of the discussion of biofuels affecting global climate change,” he said.
The study, which was recently published in the journal Science, found the production of biofuels could have a larger impact on the environment than fossil fuels if the biofuel production involves land clearing.
The study reviewed the complete life cycle of carbon emissions from biofuels, including the production process, in comparison to the fossil fuels they would replace.
While the science community generally knew the production of biofuels was not helping the environment, much of the general public had been in the dark prior to this study.
Bridget Ulrich, a chemical engineering sophomore, said when considering cleaner energy, the general public doesn’t always realize the broader scope that’s involved with land and fossil fuel use to produce the biofuels.
According to the study, the largest carbon debt came from peat lands producing palm oil. Transforming that land would take over 400 years to pay back the emissions.
Corn-based ethanol, the most dominant in the United States, if grown on converted native prairie, would take approximately 90 years to repay the debt.
Polasky said ethanol production has to compete with food demands, increasing demand for agricultural production and increasing pressure to clear more land.
Peter Hawthorne, a research assistant who also worked on the study, said people need to take the whole production process into consideration when evaluating the benefits of biofuels.
“We need to be attentive to the secondary consequences of biofuel production, such as carbon emissions from land clearing,” he said.
Despite all the concentration on the ramifications of land conversion, the study found there are solutions without leaving such a large carbon footprint.
Biofuels produced from agricultural or forestry waste and native perennial grasses – which don’t require additional land to be transformed – would result in environmental improvement.
Ulrich said the amount of effort needed to put in to the farming of perennial grasses is far less, and there is less fossil fuel needed in the harvesting and production.
Polasky said ethanol could be produced from corn stalks or other biomass, rather than the corn itself, to produce fewer emissions and reduce land-use conversion.
“Growing native plants on abandoned fields for biomass could have a much lower carbon impact because the plants’ roots restore carbon in the soil,” Hawthorne said.
Corn and other crops don’t grow with the same root systems as native plants, so the benefits aren’t as great, he said.
While these solutions produce fewer carbon emissions, research is still being conducted to find other options.
“We don’t have the infrastructure to have a completely green production of any type of energy right now,” Ulrich said. “Everything involves some type of fossil fuel just for the production of the energy.”