Obama faces climate test with EPA rule on ethanol

After the EPA issues the draft rule it will have a period for public comments before the agency issues final rules. Environmentalists and many scientists, on the other hand, say the EPA rule will open up a public discussion that will eventually result in the best way to measure indirect emissions and control them.

"To ignore it is going to really tilt the playing field in a direction that is going to send the industry off in a direction that will have to be reversed later and will be counterproductive," Jeremy Martin, a senior scientist at the Union of Concerned Scientists' clean vehicles program said by telephone.

He said the EPA could help steer the industry away from grain-based fuels to cellulosic ethanol. That industry holds promise to make ethanol out of non-food crops like agricutural waste and fast growing trees and grasses. Production of cellulosic has so far been slow and the industry risks failing to meet the federal mandate to 100 million gallons of fuel into gasoline by the end of next year. (Editing by Christian Wiessner)