A major energy bill signed last month by President Bush could decrease domestic oil consumption by increasing biofuels, but opposition to the new law has come hard and fast from an unusual source: environmentalists.

The Energy Independence and Security Act of 2007, signed Dec. 19, establishes a Renewable Fuel Standard that mandates a certain volume of biofuels be produced and mixed with gasoline sold in the United States. The amount required steadily increases each year, reaching 36 billion gallons by 2022 -- nearly eight times more than the 4.7 billion gallons produced in 2007.

Supporters of the legislation argue the mandate will lead to national security gains by decreasing U.S. dependence on foreign oil, as it would replace a large chunk of domestic gasoline consumption, currently 140 billion gallons annually, with biofuels. In addition, it could shrink the nation's environmental footprint by cutting climate-changing carbon emissions.

However, some stalwarts of environmental protection see the RFS as a potential out-of-the-frying-pan, into-the-fire solution. Among those to question the law's wisdom is Sandra Schubert, director of government affairs for the Environmental Working Group, a non-profit research organization based in Washington.

"EWG was one of the first supporters of renewable fuels and ethanol," Schubert told United Press International. "(But) we've seen over the last few years, since the first corn ethanol mandate, a lot of what we think are unintended consequences."