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 benefits.
For example, if farmers in Brazil burn and clear more rainforest to grow food because farmers in the U.S. are using their land to grow grain for fuel, that could mean a net increase in emissions of carbon dioxide, the main "greenhouse gas" linked to climate change.
The issue has been heating up for months in scientific, corporate and environmental circles. Now, the Environmental Protection Agency has indicated it plans to measure each biofuel's ...