Here is an excellent dissection of a newspaper article on biodiesel and ethanol.  Why does old style media get the story wrong almost every time?  Bio-d, a tireless Gristmill opponent of  biofuel farming, does the autopsy.

With virtually no feedback, letters to the editor are seldom published and almost never responded to by editors, and only previous articles as a guide, myths are passed on.  Actual scientific studies show that biofuel farming releases a lot more GHG throughout the whole process than even oil based fuels do.  So writers draw on previous studies, flawed as they are, to give a "fair and balanced" picture.  leaving out crucial facts.

That leaves out the most efficient, most GHG-free systems, solar panel or wind power to wheel.  Plugin battery driving.  6 kwh gets the same miles as a gallon of gas.

And what about biogas (from waste) to wheel, through a fuel cell/turbine generator?

Every kwh of electric power sent to the wheels with this system cancels over 20 times the CO2 it produces, by curtailing methane emitted by manure and fertilizer run off.

Trucks and trains have the capacity to carry methane tanks big enough to give the same utility as with diesel power.  Hypercars (ultralight carbon fiber vehicles) need a lot less fuel and therefore could carry the much smaller amount of methane fuel needed for backup for the plugin battery.

If only 5% of our energy came from biogas/waste, the rest of the CO2 we emit would be offset.  Effectively eliminating our collective carbon footprint.  That would allow renewable/conservation energy revolution along with organic fertilizer byproduct from waste biodigestion to actually reverse GHG disaster. 

Biogas/waste farm projects could use heavy subsidies, politicians and eco-lobbyists please take note of this main component of green revolution.