Been a while since i went through all this but,plenty of research out there and it is a pretty controversial subject as i am sure you know.8)
   http://www.dakotavoice.com/2009/06/nasa-study-shows-sun-responsible-for-planet-warming/ ....here is a pretty balanced viewish.Could flood you with more then flood you with the contrary so a bit meh.
    I'm still not sure myself but i think anyone who says they know for sure are ..well wrong heh. Too many leaps of faith on "our behalf" the EU option covers all aspects of our existence and clears up a lot of jumbled mess;unites everything.Imho way way too much evidence for the EU now.Anyhow all old hat really, if only we could give Tesla the greatest mind/scientist that ever drew breath the credit he deserved we would be in better shape.Opinion of course.8)