Climate Change/Health Costs from Biofuel and Gasoline Air Emissions Assessed

 A recent article from the Proceedings of the National Academy of Sciences (PNAS) (February 10, 2009 issue) attempts to “quantify and monetize the life-cycle climate-change and health effects of greenhouse gas (GHG) and fine particulate matter (PM_2.5 ) emissions from gasoline, corn ethanol, and cellulosic ethanol. The paper by Jason Hill (University of Minnesota) and colleagues is titled, “Climate change and health costs of air emissions from biofuels and gasoline”. Results estimate that at $120 per Mg Carbon (1 Mg= 1 Mega gram), the cost estimates from increased GHG levels caused by production and combustion of an additional billion gallons of ethanol or an energy-equivalent amount of gasoline using some of the alternative methods are: $246 million for gasoline, $246 million for corn ethanol (natural gas heat), $56 million for switchgrass-based cellulosic ethanol and $21 million for prairie-biomass based cellulosic ethanol. The report mentions that cellulose ethanol fared better compared with corn ethanol because “cellulosic ethanol from corn stover or perennial crops requires lower inputs” (i.e., lower fertilizer and water requirements). Cellulosic ethanol also has “lower emissions at the biorefinery because lignin combustion provides process heat and power, thereby displacing fossil fuel inputs and electricity production”. The complete paper can be accessed at the URL above. On the other hand, the Renewable Fuels Association (URL below) responded to the report, saying that the analysis is based on “based almost entirely upon insufficient and extremely uncertain analysis of potential land use changes” (related information below).

Related information on response of the Renewable Association of America to the report http://www.ethanolrfa.org/objects/documents//u_of_m_-_ethanol_worse_than_gas_analysis.pdf