Environment Report: A dispute about bio-fuels could put passage of a climate change bill at risk. Lester Graham reports corn ethanol is at the center of a dispute among some Democrats: Conventional wisdom in Washington these days is: it’s not a good idea to use food for fuel, so corn ethanol should be replaced by cellulosic ethanol – made from crops such as switchgrass. The chairman of the Ag Committee, Democrat Collin Peterson, believes the Obama administration and Democratic leaders in Congress …