The airlines are in no doubt about their problem with fuel.
They like to talk about reducing CO2 but it does not take much to read
between the lines. Alan Joyce spelt it out.

Read this Airbus bulletin;

http://tinyurl.com/7kd8spl

They want to have major plant on each continent producing biofuels
for aircraft. Just where do they think they can obtain enough land to
say nothing about water to grow such an enormous area of crops.
The area will have to be double in size to produce the fuel to
cultivate, harvest, process and transport the fuel.
This is because the ERoEI is not better than 1:1.4.

Finally it will get down to whether you want to fly or eat !
Probably, it will get down to whether the rich countries want to fly
or the poor countries want to eat.