Most of the emphasis of biofuel synthesis has been on carbon-neutral programs. Put simply, the amount of carbon-dioxide [CO2] removed from the atmosphere, by the biomass crops, is equal to the amount of CO2 emitted by biofuel synthesis and resulting fuel combustion.
This process has already been put into widespread use with ethanol, which has found its way into 95% of the US gasoline supply, in concentrations of up to 85% ethanol / gasoline. Biodiesel also works on a similar principle, and is often found as a 20% blend. Biodiesel can be used up to 100% concentration in any diesel-powered vehicle.