"Like their ethanol counterparts, biodiesel producers are chafing at the Environmental Protection Agency’s proposed methods of calculating their fuel’s greenhouse gas emissions.

The E.P.A.’s proposed rule, released on Tuesday, finds that biodiesel made from soybeans (the predominant feedstock in this country) produces, under one scenario, 22 percent fewer emissions than petroleum.

That is well short of requirements in 2007 energy legislation, which states that biodiesel must produce 50 percent fewer emissions than petroleum (though the rule proposed on Tuesday could nudge that requirement, which allows for some flexibility, down to 40 percent)."

Kate Galbraith reports for Green Inc. in the New York Times May 7, 2009.