Expertiness

First, there was truthiness, for when you feel something to be true even if the actual facts show you are wrong.
Now I think we have also identified "expertiness", for someone who feels himself to be an expert even if he doesn't actually know anything about the subject.
The Editors nails Slate writer Gregg Easterbrook for trumpeting his own "expertiness" on global warming when he is not a scientist himself nor apparently is he even capable of reporting accurately on the content of technical reports.
Expertiness personified.