Wall Street Journal: Biofuels are under siege from critics who say they crowd out food production. Now these fuels made from grass and grain, long touted as green, are being criticized as bad for the planet. At issue is whether oil alternatives — such as ethanol distilled from corn and fuels made from inedible stuff like switch grass — actually make global warming worse through their indirect impact on land use around the world. The EPA will weigh distant deforestation in gauging biofuels’ net …