Did you read the details? You're comparing transcontinental and regional travel on jets compared to "average trains" - i.e. diesel.There is a overwhelming bias pushed by the anti globalization crowd against aviation ( for obvious reasons). Your link is hilarious.
Try a real green source like treehugger.com:
The folks at 1BOG (short for One Block Off The Grid) have developed this interesting infographic about the greenest mode of transit depending on the type of journey. Click through to check it out. Home Solar Powerwww.treehugger.com
Oh and the infographic is actually from EEA - European Environment Agency:
Obviously, some anti-globalization crowd.