Set-Asides Can Be Better Climate Investment than Corn-Ethanol

G PIÑEIRO; EG JOBBÁGY; J BAKER; B MURRAY; RB JACKSON

ECOLOGICAL APPLICATIONS

Ecological Society of America

Lugar: Washington DC; Año: 2009 vol. 19 p. 277 - 282

1051-0761

Although various studies have shown that corn ethanol reduces greenhouse gas(GHG) emissions by displacing fossil fuel use, many of these studies fail to include how land-usehistory affects the net carbon balance through changes in soil carbon content. We evaluated theeffectiveness and economic value of corn and cellulosic ethanol production for reducing netGHG emissions when produced on lands with different land-use histories, comparing thesestrategies with reductions achieved by set-aside programs such as the Conservation ReserveProgram (CRP). Depending on prior land use, our analysis shows that C releases from the soilafter planting corn for ethanol may in some cases completely offset C gains attributed to biofuelgeneration for at least 50 years. More surprisingly, based on our comprehensive analysis of 142soil studies, soil C sequestered by setting aside former agricultural land was greater than the Ccredits generated by planting corn for ethanol on the same land for 40 years and had equal orgreater economic net present value. Once commercially available, cellulosic ethanol produced inset-aside grasslands should provide the most efficient tool for GHG reduction of any scenariowe examined. Our results suggest that conversion of CRP lands or other set-aside programs tocorn ethanol production should not be encouraged through greenhouse gas policies