LIFECYCLE EMISSIONS FROM FOSSIL FUELS USED IN AIRPLANES, VERSUS LIFECYCLE EMISSIONS FROM BIOJET FUELS. AT EACH STAGE IN THE DISTRIBUTION CHAIN, CO2 IS EMITTED. IN THE CASE OF BIOFUELS THE CO2 WILL BE REABSORBED TO A LARGE EXTENT AS THE NEXT GENERATION OF FEEDSTOCK IS GROWN. SOURCE: BEGINNER’S GUIDE TO AVIATION BIOFUELS, 2009