Many airlines are testing biofuels now and generating good results:

…findings from the almost 1200 flights that the biofuel mix was not only reliable but delivered 1 per cent better efficiency. (Lufthansa says its bio kerosene was 85 per cent Camelina Sativa (wild flax), 15 per cent Jatropha oil and 5 per cent animal fat.)

KLM is about to start their own trials.

This, to me, is one of the positive and effective directions we can be taking toward emissions control and reduction. Everyone wins here.