The Corn Ethanol Con
Pineiro, G., Jobbagy, E.G., Baker, J., Murray, B.C. and Jackson, R.B. 2009. Set-asides can be better climate investment than corn ethanol. Ecological Applications 19: 277-282.
To find out, the authors evaluated "the effectiveness and economic value of corn- and cellulosic ethanol production for reducing net GHG [greenhouse gas] emissions when produced on lands that were previously under crop production, previously set aside, or remained as native vegetation, comparing them with carbon sequestration rates achieved by conservation programs," such as the Conservation Reserve Program (CRP), through which the U.S. federal government establishes 10-15 year contracts with farmers and pays them to keep land out of production.
The five researchers determined that "carbon releases from the soil after planting corn for ethanol may in some cases completely offset carbon gains attributed to biofuel generation for at least 50 years." In addition, they found that "soil carbon sequestered by setting aside former agricultural land was greater than the carbon credits generated by planting corn for ethanol on the same land for 40 years and had equal or greater economic net present value." And if forests are cleared for corn ethanol production, the outcome is determined to be even worse.
"Considering current ethanol incentives and typical CRP contracts," according to Pineiro et al., "extending current CRP contracts or enrolling new CRP lands appear to be cheaper strategies for sequestering GHG than converting such lands to corn ethanol for at least a century [italics added]."
One lesson to be learned from this fiasco is that government edicts regarding complex scientific issues should not be issued without a thorough consideration of all the pertinent facts, especially those that are hotly debated within the scientific community.