John Kerry flies private jet aircraft, a lot. I did a little checking around. His plane burns likely 6 to 7 gallons of fuel per minute, about what I burn in a week.
I think before he has the right to tell me anything about saving fuel, he needs to start flying commercial.
If he wants to go around boring holes in the sky at speeds approaching the speed of sound, i have no problems with it. However, if he wants to be the spokesman of global warming, he really should stop contributing so much to warming the globe.