When the 2008 farm bill passed in May, there was much speculation about its potential impact on the development of cellulosic ethanol. That is a type of fuel harder to create than its grain-based cousins, but one that could be derived from a much wider range of potential sources — from corn stalks, rice straw and other non-edible parts of plants, to wood chips and switchgrass.

The bill, which was drafted amid the food-versus-fuel debate attached to corn-based ethanol and rising global food prices, put special emphasis on cellulosic ethanol production, providing tax credits for refiners ($1.01 a gallon), for feedstock producers ($45 a ton), and created other incentives to spur the development of cellulosic research and infrastructure.

(The term “cellulosic ethanol” is a reference to cellulose, an energy-rich molecule in plants that scientists say can be converted to fuel. The term was coined to contrast this type of fuel with ethanol made from the simpler starch molecule in grains like corn.)

In total, about $1 billion in subsidies was set aside for advanced biofuels, according to a Congressional Research Service report issued in August — principally for cellulosic fuels.

For all this, however, a group of nearly two dozen academics and scientists, writing in the Oct. 3 issue of Science magazine, sounded a note of caution.

“A cellulosic biofuels industry could have many positive social and environmental attributes,” the authors of the policy note write, “but it could also suffer from many of the sustainability issues that hobble grain-based biofuels, if not implemented the right way.”  For the complete article..  CLICK