The lead voice on concern for global climate change is the Goddard Institute for Space Studies. GISS is part of NASA, though it’s located at Columbia University. They are the one who provide much of the context that’s turned global temperature data into an instrument of hysteria.
Recently, some of GISS’s work has been reexamined. Steve McIntyre of ClimateAudit.org seems to be leading the charge here. McIntyre found 1998 was not the hottest year on record in the United States, as had been claimed. It’s now replaced (though barely) by 1934.
After GISS acknowledged their errors and changed their numbers, the new data show 5 of the 10 hottest years on record in the U.S. came before World War II!
The numbers aren’t radically different, but it’s going to be very tough to spin them the same way they were spun before.
There’s a pretty good summary of what went on here, on Daily Tech.