Speaking of on topic... there's a nice article today from a guy in Australia detailing how ALL of the rise in the USA surface temperature since 1900 is due to the adjustments that have been made to the actual temperatures recorded rather than the data itself... making one wonder about the agenda at work within Mr. Hansens fiefdom.
The article is not peer reviewed science but relies entirely on data on the NASA/GISS website so it appears to be quite credible. Mr. Hammer is a spectroscopic engineer and has written on warming before from that discipline's perspective. Here's the article:
Jennifer Marohasy » How the US Temperature Record is Adjusted