Didn't Greenland have a warmer climate around the time Erik the Red settled there? I remember reading somthing about a Medieval warm period. Might that account for why Erik labled it Greenland? My memories failing me here, I can't remember the web address of the article.
EDIT:
http://en.wikipedia.org/wiki/Medieval_Warm_Period I'll just use the info WIKI has on it for now. I know I read a more in depth article about it somwhere though. I believe it was cited as an example to dismiss the theory of human activity producing global warming or somthing of that sort.