I didn't know Patrick Geryl had a Wikipedia page actually, because normally, any articles there about cranks will soon get removed. But you're right it is there and here it is:
http://en.wikipedia.org/wiki/User:Nathan_hutchcraft/Patrick_Geryl
(Not sure why it has "User:Nathan_hutchcraft" in the title and url either - I"ve never seen that before on a Wiki page - does that mean that's the author and it's earmarked for review or something, does anyone know?)
Anyway, the author's claim that "some scientists find that his theories has (sic) good credibility and identify him as credible person," is rubbish - at least as far as genuine scientists are concerned. "Credible Edgar Cayce" is mentioned, but he was an alleged psychic, not a scientist. I would imagine that Wiki page will be consigned to the dustbin shortly …
As far as Geryl himself is concerned, you did say you had read the article here at 2012hoax, but there are several threads as well in the forum worth reading through as well, if you search "Patrick Geryl" including a good one started by Bikenbeer2000 which I've just spent 10 minutes trying to find, without success (which is why it's taken me so long to make this post.) Bikenbeer, if you're reading this, have you any idea where it is? (It's from about 3 weeks ago I think.)
Anyway, bottom line with Geryl is, he's a crackpot with many failed predictions to his name already and not to be taken seriously at all.