Good post....except for the two engine part. I fly single engine turbines (PC-12 and Caravan) and four engine jets (KC135R) and I can't say I'm any more concerned in the singles. Even though I burn a lot of Jet-A, I am concerned for the future of aviation fuels. When I drive my hybrid (HCH) to work then fly around burning a gallon every two seconds, I can't help but to think about it.