Round trip on Air Force 1 from Washington to Copenhagen and back - 57,000 gallons of jet fuel.
Backup 747 in case you need it - 57,000 gallons of jet fuel
C17 to transport limousines and other vehicles - 40,000 gallons of jet fuel.
Total fuel consumed for trip to global warming summit 157,000 gallons.
Telling the rest of the world they need to reduce their carbon footprint? Priceless
(I based my calculations on a HowStuffWorks.com article guessing that it would be an 8 hour flight from the US to Copenhagen. I also made an educated guess on how much fuel a C17 would use but I think it is in the ballpark. I did not count additional support planes but my guess is there are several.)