Time Magazine: New fuel-economy rules proposed by the federal Department of Transportation and the Environmental Protection Agency are the first major move by the U.S. toward cracking down on greenhouse-gas emissions. The proposed program includes miles-per-gallon requirements and national emissions standards under the EPA’s greenhouse-gas-emissions guidelines for model years from 2012 to 2016. You’d think that environmental groups would be overjoyed. (See pictures of the effects of global …