TLDR 'Scott Irwin, an economist at the University of Illinois calculates...the extra cost for biodiesel comes to about $1.80 per gallon right now, meaning that the biofuel law is costing Americans about $5.4 billion a year'.

'Biodiesel is very expensive, relative to petroleum diesel'

'Defenders of biodiesel insist that it's a much cleaner fuel than regular diesel, because it doesn't come from the ground, but from soybean plants that capture carbon dioxide from the air as they grow. In fact, by the EPA's calculations, replacing petroleum-based fuel with biodiesel will cut greenhouse emissions at least in half.

A growing number of environmentalists, however, say that this calculation is dead wrong. They say that if more soybeans are needed to make fuel in addition to food, it inevitably means that people somewhere on Earth will have to plow up grasslands or cut down forests in order to grow that additional supply — and clearing such land releases huge amounts of carbon dioxide into the atmosphere.'