|February 09, 2009|
New Study Weighs Impacts of Corn Ethanol
|A new study from the University of Minnesota finds that biofuel made from corn can be as harmful to the environment as gasoline, and that the combined costs to climate-change and health exceed that of gas. |
The study notes that the environmental impacts of energy use can impose large costs on society. It quantifies and monetizes the life-cycle climate-change and health effects of greenhouse gas (GHG) and fine particulate matter (PM2.5) emissions from gasoline, corn ethanol, and cellulosic ethanol.
The study found that for each billion ethanol-equivalent gallons of fuel produced and combusted in the US, the combined climate-change and health costs are $469 million for gasoline, $472-952 million for corn ethanol depending on biorefinery heat source (natural gas, corn stover, or coal) and technology, but only $123-208 million for cellulosic ethanol depending on feedstock (prairie biomass, Miscanthus, corn stover, or switchgrass).
Moreover, a geographically explicit life-cycle analysis that tracks PM2.5 emissions and exposure relative to U.S. population shows regional shifts in health costs dependent on fuel production systems. Because cellulosic ethanol can offer health benefits from PM2.5 reduction that are of comparable importance to its climate-change benefits from GHG reduction, a shift from gasoline to cellulosic ethanol has greater advantages than previously recognized.
These advantages are critically dependent on the source of land used to produce biomass for biofuels, on the magnitude of any indirect land use that may result, and on other as yet unmeasured environmental impacts of biofuels.
The research is the latest in the debate of the merits of first generation biofuels made from corn. The lead author of the report was Jason Hill, a resident fellow in the University of Minnesota’s Institute on the Environment. It is the first to examine and monetize lifecycle climate change and health effects from greenhouse and fine particulate matter emissions from gasoline, corn ethanol and cellulosic ethanol.
"Our work highlights the need to expand the biofuels debate beyond its current focus on climate change to include a wider range of effects such as their impacts on air quality," Hill, told BusinessGreen.com. "To understand the environmental and health consequences of biofuels, we must look well beyond the tailpipe to how and where biofuels are produced."Greenbiz.