USA Today: A broad energy law signed by President Bush this month requires a major increase in corn-based ethanol and other biofuels to combat global warming and reduce U.S. dependence on imported oil. But it won’t come without a cost. The law calls for production of 36 billion gallons of renewable fuel by 2022. That includes 15 billion gallons of corn-based ethanol, about double current production ability. There also are incentives for biodiesel from products such as soybeans and cellulosic …