I'm going to have to look up some chemistry tonight but this doesn't sound right at all:

"An average European flight produces 400 kg of greenhouse gases per passenger"

And exactly what is the average European flight? Are they talking just intra-European flights, or all flights that have a European origin or destination? update - reading further looks like just intra-European flights based on the "short-haul" sentence.

>http://www.greenmuze.com/climate/travel/1850-shocking-polar-bear-ad.html