In his State of the Union message to Congress in January, President Bush unveiled a plan to reduce the nation's gasoline consumption by 20 percent over the next decade.

Reaching that goal would require a dramatic increase in the use of renewable fuels and greater efficiency in the fleet of American cars and trucks.

The White House says the new renewable fuel standards announced this week could help chart the way to greater U.S. independence from foreign oil.

It's been two years since the U.S. Congress passed the Energy Policy Act, a law that requires 30 billion liters of renewable fuel be blended into gasoline sold in the United States by 2012.

This week [4/10/07] Environmental Protection Agency administrator Stephen Johnson announced the final rules. He says the new renewable fuel standard or RFS strengthens the nation's energy security, supports American farmers and protects the environment. "The increased use of renewable fuels under the RFS will prevent the release of greenhouse gas emissions equivalent of up to 13 million metric tons, which is equal to the carbon dioxide emissions of nearly 2.3 million automobiles."

The Bush Administration says it would like to curb emissions even further, and hopes to grow renewable and alternative fuel use to 140 billion liters by the 2017. Secretary of Energy Samuel Bodman is encouraged that the U.S. can meet this ambitious goal, given the strong market response to renewable fuel development.

Private industry has invested over $2 billion in the first quarter of this current calendar year.

Bodman says that level of investment persuades him that the Bush Administration's long-term renewable fuel targets can be achieved, although not by corn-based ethanol alone. He says cellulosic biomass such as switchgrass and woodchips must be added to the mix. "One could see doubling the amount of renewable fuel that we can generate from corn, which would put us at roughly 60 billion liters, but to get to the 140-billion-liter level we are really going to need a major contribution from cellulosic ethanol."

A recent U.S. Department of Agriculture report predicts farmers will plant 15 percent more corn, or maize, this year because of the demand for ethanol. 

Steven Bantz is a senior engineer with the Union of Concerned Scientists, a science-based research group. He warns that pushing bio-resources too far too fast could yield unintended environmental consequences and questions the impact of increased fertilizer and pesticide use and the strain on soil and water tables.

Bantz says safeguards must be put in place that conserve biodiversity and limit the risk of invasive and genetically modified plants. He also cautions that the renewable standard could open the door to non-renewable alternatives such as liquid fuel produced from coal. "While coal is popular and readily available, its use would be a step backward because a gallon of coal-derived fuel actually has about twice the amount of global warming pollution when you look at it on a life-cycle basis."

Bantz says the fastest and most efficient way to cut U.S. oil dependence and global warming emissions is to mandate aggressive fuel economy standards for cars and trucks. He says proposals now before Congress would require a 4 percent annual increase in fuel economy over ten years. "We are getting close to being able to pass significant legislation."

President Bush embraced the 4 percent annual target in his State of the Union speech earlier this year. But U.S. automakers have consistently resisted such increases saying that the move would hurt the U.S. economy and put smaller and potentially more dangerous cars on the road."